Fermentation

19 pages, 2526 KiB

Open AccessArticle

The Profile of Exopolysaccharides Produced by Various Lactobacillus Species from Silage during Not-Fat Milk Fermentation

by Elena Nikitina, Tatyana Petrova, Alya Sungatullina, Oxana Bondar, Maria Kharina, Polina Mikshina, Elizaveta Gavrilova and Airat Kayumov

Fermentation 2023, 9(2), 197; https://doi.org/10.3390/fermentation9020197 - 20 Feb 2023

Cited by 9 | Viewed by 2564

Abstract

The exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) and released into fermented milk play a protective role from stress factors as well as improve emulsifying and thickening properties of the product, reduce syneresis, and increase elasticity. Here we report the relationship between [...] Read more.

The exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) and released into fermented milk play a protective role from stress factors as well as improve emulsifying and thickening properties of the product, reduce syneresis, and increase elasticity. Here we report the relationship between the properties, composition, and microstructure of EPS produced by six different strains of lactobacilli (L. bulgaricus and five strains isolated from silage). The presence of fructose together with negative-charged uronic acid was found to play a significant role in changing the EPS properties. Thus, the increased fraction of rhamnose and arabinose and a decrease in xylose leads to compaction of the EPS, decreased porosity and increased both OH- and superoxide scavenging and Fe-chelating activities. By contrast, increased xylose and low rhamnose and arabinose apparently leads to loss of large aggregates and high DPPH activity and FRAP. The high content of glucose, however, provides the formation of large pores. The increased fructan fraction (69.9 mol%) with a high fraction of galacturonic (18.2 mol%) and glucuronic acids (6.7 mol%) apparently determines the highly porous spongy-folded EPS microstructure. Taken together, our results indicate that both the quantitative characteristics of the individual components of the fraction and the structural features of EPS are important for the antioxidant potential of fermented milk and depend on the strain used for milk fermentation, suggesting the advantage of a multicomponent starter to achieve the optimal beneficial properties of fermented milk. Full article

(This article belongs to the Special Issue Application of Microbial Fermentation in Organic Matter Production)

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31 pages, 2216 KiB

Open AccessReview

Petroleum Hydrocarbon Catabolic Pathways as Targets for Metabolic Engineering Strategies for Enhanced Bioremediation of Crude-Oil-Contaminated Environments

by Nandita Das, Ankita Das, Sandeep Das, Vasudha Bhatawadekar, Prisha Pandey, Kamlesh Choure, Samir Damare and Piyush Pandey

Fermentation 2023, 9(2), 196; https://doi.org/10.3390/fermentation9020196 - 20 Feb 2023

Cited by 14 | Viewed by 6527

Abstract

Anthropogenic activities and industrial effluents are the major sources of petroleum hydrocarbon contamination in different environments. Microbe-based remediation techniques are known to be effective, inexpensive, and environmentally safe. In this review, the metabolic-target-specific pathway engineering processes used for improving the bioremediation of hydrocarbon-contaminated [...] Read more.

Anthropogenic activities and industrial effluents are the major sources of petroleum hydrocarbon contamination in different environments. Microbe-based remediation techniques are known to be effective, inexpensive, and environmentally safe. In this review, the metabolic-target-specific pathway engineering processes used for improving the bioremediation of hydrocarbon-contaminated environments have been described. The microbiomes are characterised using environmental genomics approaches that can provide a means to determine the unique structural, functional, and metabolic pathways used by the microbial community for the degradation of contaminants. The bacterial metabolism of aromatic hydrocarbons has been explained via peripheral pathways by the catabolic actions of enzymes, such as dehydrogenases, hydrolases, oxygenases, and isomerases. We proposed that by using microbiome engineering techniques, specific pathways in an environment can be detected and manipulated as targets. Using the combination of metabolic engineering with synthetic biology, systemic biology, and evolutionary engineering approaches, highly efficient microbial strains may be utilised to facilitate the target-dependent bioprocessing and degradation of petroleum hydrocarbons. Moreover, the use of CRISPR-cas and genetic engineering methods for editing metabolic genes and modifying degradation pathways leads to the selection of recombinants that have improved degradation abilities. The idea of growing metabolically engineered microbial communities, which play a crucial role in breaking down a range of pollutants, has also been explained. However, the limitations of the in-situ implementation of genetically modified organisms pose a challenge that needs to be addressed in future research. Full article

(This article belongs to the Special Issue Bioprocess and Metabolic Engineering)

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16 pages, 2684 KiB

Open AccessArticle

Transcriptional Response of Multi-Stress-Tolerant Saccharomyces cerevisiae to Sequential Stresses

by Ane Catarine Tosi Costa, Mariano Russo, A. Alberto R. Fernandes, James R. Broach and Patricia M. B. Fernandes

Fermentation 2023, 9(2), 195; https://doi.org/10.3390/fermentation9020195 - 20 Feb 2023

Cited by 5 | Viewed by 2839

Abstract

During the fermentation process, yeast cells face different stresses, and their survival and fermentation efficiency depend on their adaptation to these challenging conditions. Yeast cells must tolerate not only a single stress but also multiple simultaneous and sequential stresses. However, the adaptation and [...] Read more.

During the fermentation process, yeast cells face different stresses, and their survival and fermentation efficiency depend on their adaptation to these challenging conditions. Yeast cells must tolerate not only a single stress but also multiple simultaneous and sequential stresses. However, the adaptation and cellular response when cells are sequentially stressed are not completely understood. To explore this, we exposed a multi-stress-tolerant strain (BT0510) to different consecutive stresses to globally explore a common response, focusing on the genes induced in both stresses. Gene Ontology, pathway analyses, and common transcription factor motifs identified many processes linked to this common response. A metabolic shift to the pentose phosphate pathway, peroxisome activity, and the oxidative stress response were some of the processes found. The SYM1, STF2, and HSP genes and the transcription factors Adr1 and Usv1 may play a role in this response. This study presents a global view of the transcriptome of a multi-resistance yeast and provides new insights into the response to sequential stresses. The identified response genes can indicate future directions for the genetic engineering of yeast strains, which could improve many fermentation processes, such as those used for bioethanol production and beverages. Full article

(This article belongs to the Special Issue Yeast, Biofuels, and Value-Added Products)

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19 pages, 2862 KiB

Open AccessArticle

Improving the Functionality of Lentil–Casein Protein Complexes through Structural Interactions and Water Kefir-Assisted Fermentation

by Mohammad Alrosan, Thuan-Chew Tan, Azhar Mat Easa, Muhammad H. Alu’datt, Carole C. Tranchant, Ali Madi Almajwal, Sana Gammoh, Sofyan Maghaydah, Mohammed Ali Dheyab, Mahmood S. Jameel and Ali Al-Qaisi

Fermentation 2023, 9(2), 194; https://doi.org/10.3390/fermentation9020194 - 20 Feb 2023

Cited by 15 | Viewed by 3461

Abstract

Highly nutritious lentil proteins (LP) have recently attracted interest in the food industry. However, due to their low solubility, extensive application of LP is severely limited. This study describes a new and successful method for overcoming this challenge by improving the nutritional–functional properties [...] Read more.

Highly nutritious lentil proteins (LP) have recently attracted interest in the food industry. However, due to their low solubility, extensive application of LP is severely limited. This study describes a new and successful method for overcoming this challenge by improving the nutritional–functional properties of LP, particularly their solubility and protein quality. By combining protein complexation with water kefir-assisted fermentation, the water solubility of native LP (~58%) increases to over 86% upon the formation of lentil–casein protein complexes (LCPC). Meanwhile, the surface charge increases to over −40 mV, accompanied by alterations in secondary and tertiary structures, as shown by Fourier-transform infrared and UV-vis spectra, respectively. In addition, subjecting the novel LCPC to fermentation increases the protein digestibility from 76% to over 86%, due to the reduction in micronutrients that have some degree of restriction with respect to protein digestibility. This approach could be an effective and practical way of altering plant-based proteins. Full article

(This article belongs to the Special Issue Fermentation Processes: Modeling, Optimization and Control)

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13 pages, 2913 KiB

Open AccessArticle

Pigment Production of Chlamydomonas Strains in Response to Norflurazon and ZnO Nanoparticles

by Thanaporn Intha and Anchalee Sirikhachornkit

Fermentation 2023, 9(2), 193; https://doi.org/10.3390/fermentation9020193 - 19 Feb 2023

Cited by 2 | Viewed by 2295

Abstract

Numerous species of microalgae have been utilized for pigment production. More and more species are gaining popularity due to their ability to accumulate pigments with varying chemical compositions and the fact that some have distinctive byproducts that can be co-produced. Despite the fact [...] Read more.

Numerous species of microalgae have been utilized for pigment production. More and more species are gaining popularity due to their ability to accumulate pigments with varying chemical compositions and the fact that some have distinctive byproducts that can be co-produced. Despite the fact that many of the species have unique by-products and traits, they are not being used economically due to high production costs. Utilizing agricultural and industrial wastewater for algae cultivation is one way to lower manufacturing costs. Herbicide-contaminated wastewater can result from agricultural contamination. Norflurazon is a popular pesticide frequently used for weed control. The presence of norflurazon in water renders that water unusable and requires proper treatment. Nanoparticles of ZnO (ZnO NPs), on the other hand, are utilized in a variety of industrial productions of numerous household goods. Water contaminated with ZnO NPs can present potential risks to human health and the environment. In this study, two field isolates of the green microalga Chlamydomonas reinhardtii, a widely used model organism, were examined for their reaction to these two compounds in order to assess the responses of different natural strains to environmental stresses. Norflurazon at 10 µM had a higher inhibitory effect on growth and pigment production than ZnO NPs at 200 mg L⁻¹. Although both norflurazon and ZnO NPs inhibit cell growth and pigmentation, they do so through distinct processes. Norflurazon induces oxidative stress in cells, resulting in photosystem damage. ZnO nanoparticles, on the other hand, did not cause photosystem damage but rather mechanical cell damage and disintegration. In addition, the physiological responses of the two Chlamydomonas strains were distinct, supporting the utilization of natural algal strains for specific types of environmental pollutants. Full article

(This article belongs to the Special Issue Pigment Production in Submerged Fermentation)

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11 pages, 3270 KiB

Open AccessArticle

The Potential of Using Istrian Albumin Cheese Whey in the Production of Whey Distillate

by Darija Bendelja Ljoljić, Samir Kalit, Josipa Kazalac, Iva Dolenčić Špehar, Marin Mihaljević Žulj, Luna Maslov Bandić and Milna Tudor Kalit

Fermentation 2023, 9(2), 192; https://doi.org/10.3390/fermentation9020192 - 19 Feb 2023

Cited by 4 | Viewed by 1934

Abstract

In addition to the production of albumin cheese, biogas and whey powder, whey has also been used as a raw material for the production of alcoholic beverages. The aim of this research was to investigate the potential of using Istrian albumin cheese whey [...] Read more.

In addition to the production of albumin cheese, biogas and whey powder, whey has also been used as a raw material for the production of alcoholic beverages. The aim of this research was to investigate the potential of using Istrian albumin cheese whey in the production of whey distillate. Three batches of Istrian albumin cheese were produced in a small-scale cheese plant. The remaining whey after the production of albumin cheese was fermented using Kluyveromyces marxianus subsp. marxianus for 5 days and then distilled. In the whey samples before and after fermentation, the content of total solids, protein, milk fat and lactose was determined. The ethanol content and the composition of volatile compounds in the distillate was determined. The content of all components of the chemical composition of whey, except for the content of fat, decreased during fermentation. In the whey distillate with an alcohol content of 35%, the following compounds were determined: acetaldehyde, methanol, n-propanol, i-butanol, n-butanol, 3-methyl-1-ol, 2-methylbutan-1-ol and ethyl-lactate. The distillate obtained confirmed the potential of using whey for the production of spirits. However, further research is needed due to the potential presence of the harmful effects of certain volatile compounds on human health. Full article

(This article belongs to the Special Issue Fermented Dairy Products: Processing Technology, Microbiology and Health Benefits)

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17 pages, 3153 KiB

Open AccessArticle

Overexpression of a Novel Vacuolar Serine Protease-Encoding Gene (spt1) to Enhance Cellulase Production in Trichoderma Reesei

by Cheng Yao, Ningning Sun, Weihao Gao, Yu Sun, Jiaxin Zhang, Hong Liu and Yaohua Zhong

Fermentation 2023, 9(2), 191; https://doi.org/10.3390/fermentation9020191 - 19 Feb 2023

Cited by 3 | Viewed by 2198

Abstract

Trichoderma reesei is widely applied as the major industrial fungus for the production of cellulases used for the conversion of lignocellulosic biomass to biofuels and other biobased products. The protein secretion pathway is vital for cellulase secretion, but few reports are related to [...] Read more.

Trichoderma reesei is widely applied as the major industrial fungus for the production of cellulases used for the conversion of lignocellulosic biomass to biofuels and other biobased products. The protein secretion pathway is vital for cellulase secretion, but few reports are related to the role of the vacuole in cellulase production. Here, we identified a novel vacuolar serine protease gene spt1 and investigated the ability of T. reesei to secrete cellulases by disrupting, complementing and overexpressing the spt1 gene. Amino acid sequence analysis of the Spt1 protein showed that it belongs to the subtilisin S8 family and has the conserved catalytic triples (Asp, His, Ser) of the serine protease. The deletion of spt1 did not lead to a decrease in extracellular protease activity, and the observation of mycelia with the Spt1–eGFP fusion expression and the vacuolar membrane dye FM4-64 staining confirmed that Spt1 was an intracellular protease located in the vacuoles of T. reesei. However, the spt1 gene deletion significantly reduced spore production and cellulase secretion, while the spt1 complementation recovered these traits to those of the parental strain. When spt1 was overexpressed by using its native promoter and introducing multiple copies, the cellulase secretion was improved. Furthermore, a strong promoter, Pcdna1, was used to drive the spt1 overexpression, and it was found that the cellulase production was significantly enhanced. Specifically, the filter paper activity of the spt1 overexpression strain SOD-2 reached 1.36 U/mL, which was 1.72 times higher than that of the parental strain. These findings demonstrated that the spt1 gene can be a powerful target for increasing cellulase production in T. reesei, which suggests a possible important role of the vacuole in the cellulase secretion pathway and provides new clues for improving strains for efficient cellulase production. Full article

(This article belongs to the Special Issue Biorefinery of Lignocellulosic Biomass)

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18 pages, 3738 KiB

Open AccessFeature PaperArticle

Comparison of Aqueous and Lactobacterial-Fermented Mercurialis perennis L. (Dog’s Mercury) Extracts with Respect to Their Immunostimulating Activity

by Peter Lorenz, Ilona Zilkowski, Lilo K. Mailänder, Iris Klaiber, Sven Nicolay, Manuel Garcia-Käufer, Amy M. Zimmermann-Klemd, Claudia Turek, Florian C. Stintzing, Dietmar R. Kammerer and Carsten Gründemann

Fermentation 2023, 9(2), 190; https://doi.org/10.3390/fermentation9020190 - 18 Feb 2023

Cited by 3 | Viewed by 2230

Abstract

Lactic acid (LA) fermentation of dog’s mercury (M. perennis L.) herbal parts was investigated in samples inoculated with either Lactobacteria (Lactobacillus plantarum and Pediococcus pentosaceus, LBF) or whey (WF). Depending on fermentation time, LA concentrations were monitored in a range [...] Read more.

Lactic acid (LA) fermentation of dog’s mercury (M. perennis L.) herbal parts was investigated in samples inoculated with either Lactobacteria (Lactobacillus plantarum and Pediococcus pentosaceus, LBF) or whey (WF). Depending on fermentation time, LA concentrations were monitored in a range of 3.4–15.6 g/L with a concomitant pH decline from 6.5 to 3.9. A broad spectrum of cinnamic acids depsides containing glucaric, malic and 2-hydroxyglutaric acids along with quercetin and kaempferol glycosides were detected by LC-DAD-ESI-MSⁿ. Moreover, in this study novel constituents were also found both in unfermented and fermented extracts. Furthermore, amino acids and particular Lactobacteria metabolites such as biogenic amines (e.g., putrescine, 4-aminobutyric acid, cadaverine) and 5-oxoproline were assigned in WF extracts by GC-MS analysis after silylation. Enhanced NFκB and cytokine expression (IL-6, TNFα, IL-8 and IL-1β) was induced by all extracts, both non-fermented and fermented, in NFκB-THP-1 reporter cells, showing a concentration-dependent immunostimulatory effect. The WF extracts were tested for micronuclei formation in THP-1 cells and toxicity in luminescent bacteria (V. fischeri), whereby no mutagenic or toxic effects could be detected, which corroborates their safe use in pharmaceutical remedies. Full article

(This article belongs to the Special Issue Recent Trends in Lactobacillus and Fermented Food)

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19 pages, 2131 KiB

Open AccessArticle

Bioconversion of a Lignocellulosic Hydrolysate to Single Cell Oil for Biofuel Production in a Cost-Efficient Fermentation Process

by Zora S. Rerop, Nikolaus I. Stellner, Petra Graban, Martina Haack, Norbert Mehlmer, Mahmoud Masri and Thomas B. Brück

Fermentation 2023, 9(2), 189; https://doi.org/10.3390/fermentation9020189 - 18 Feb 2023

Cited by 5 | Viewed by 2742

Abstract

Cutaneotrichosporon oleaginosus is a highly efficient single cell oil producer, which in addition to hexoses and pentoses can metabolize organic acids. In this study, fed-batch cultivation with consumption-based acetic acid feeding was further developed to integrate the transformation of an industrial paper mill [...] Read more.

Cutaneotrichosporon oleaginosus is a highly efficient single cell oil producer, which in addition to hexoses and pentoses can metabolize organic acids. In this study, fed-batch cultivation with consumption-based acetic acid feeding was further developed to integrate the transformation of an industrial paper mill lignocellulosic hydrolysate (LCH) into yeast oil. Employing pentose-rich LCH as a carbon source instead of glucose significantly improved both biomass formation and lipid titer, reaching 55.73 ± 5.20 g/L and 42.1 ± 1.7 g/L (75.5% lipid per biomass), respectively. This hybrid approach of using acetic acid and LCH in one process was further optimized to increase the share of bioavailable carbon from LCH using a combination of consumption-based and continuous feeding. Finally, the techno-economic analysis revealed a 26% cost reduction when using LCH instead of commercial glucose. In summary, we developed a process leading to a holistic approach to valorizing a pentose-rich industrial waste by converting it into oleochemicals. Full article

(This article belongs to the Special Issue Yeast, Biofuels, and Value-Added Products)

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12 pages, 1427 KiB

Open AccessArticle

Overproduction of Laccase by Trametes versicolor and Pycnoporus sanguineus in Farnesol-Pineapple Waste Solid Fermentation

by Emanueli Backes, Camila Gabriel Kato, Verci Alves de Oliveira Junior, Thaís Marques Uber, Luís Felipe Oliva dos Santos, Rúbia Carvalho Gomes Corrêa, Adelar Bracht and Rosane Marina Peralta

Fermentation 2023, 9(2), 188; https://doi.org/10.3390/fermentation9020188 - 18 Feb 2023

Cited by 7 | Viewed by 2742

Abstract

The effect of farnesol, a sesquiterpene alcohol, on the production of laccases by Trametes versicolor and Pycnoporus sanguineus in pineapple waste solid-state fermentation was evaluated. Extracellular laccase production reached a maximum of 77.88 ± 5.62 U/g (236% above control) in farnesol-induced cultures of [...] Read more.

The effect of farnesol, a sesquiterpene alcohol, on the production of laccases by Trametes versicolor and Pycnoporus sanguineus in pineapple waste solid-state fermentation was evaluated. Extracellular laccase production reached a maximum of 77.88 ± 5.62 U/g (236% above control) in farnesol-induced cultures of T. versicolor on the 17th day, whereas in a similar P. sanguineus culture, a maximal laccase activity of 130.95 ± 2.20 U/g (159% increase) was obtained on the 17th day. A single 45 KDa laccase was produced by both fungi under the influence of farnesol. These and other data allow us to conclude that farnesol acted as an inducer of the same form of laccase in both fungi. Farnesol disfavored fungal growth by increasing the lag phase, but it also clearly improved the oxidative state of the cultures. Contrary to the results obtained previously in submerged cultures, farnesol did not promote hyperbranching in the fungal mycelia. This is the first demonstration that farnesol is an excellent inducer of laccases in T. versicolor and P. sanguineus in solid-state cultivation. In quantitative terms, the results can be regarded as an excellent starting point for developing industrial or at least pre-industrial procedures to produce laccases using T. versicolor and P sanguineus under the stimulus of farnesol. Full article

(This article belongs to the Special Issue Current and Future Trends in Food Waste Valorization for the Production of Value-Added Products)

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9 pages, 1409 KiB

Open AccessCommunication

The Effect of a Glutathione (GSH)-Containing Cryo-Protectant on the Viability of Probiotic Cells Using a Freeze-Drying Process

by Trung Hau Nguyen, Jin-Seong Kim, Hyuk-Ju Kwon and Chang-Ho Kang

Fermentation 2023, 9(2), 187; https://doi.org/10.3390/fermentation9020187 - 17 Feb 2023

Cited by 8 | Viewed by 2312

Abstract

Lactic acid bacteria (LAB) and probiotics promise specific health benefits to their host. However, good storage stability is a prerequisite for their functioning and industrial use. This study aimed to evaluate glutathione (GSH) as a potential protective agent for improving microbial stability deteriorated [...] Read more.

Lactic acid bacteria (LAB) and probiotics promise specific health benefits to their host. However, good storage stability is a prerequisite for their functioning and industrial use. This study aimed to evaluate glutathione (GSH) as a potential protective agent for improving microbial stability deteriorated by freeze-drying, freeze-thawing, and cold treatments. In this study, the optimal concentration of glutathione (50% w/w) was 1%, showing effective protection on the viability and stability of various LAB strains (Lactiplantibacillus plantarum MG4229 and MG4296, Lactococcus lactis MG5125, Limosilactobacillus fermentum MG4295, Lacticaseibacillus paracasei MG5012, and Bifidobacterium animalis ssp. lactis MG741). Glutathione-containing protectants considerably improved the viability of all of these strains after freeze-drying compared with non-coated probiotics. Survivability in the gastrointestinal (GI) tract, accelerated stability tests, and adhesion assays on intestinal epithelial cells were performed to determine whether glutathione enhances bacterial stability. Based on morphological observations, protectants containing GSH were coated onto the cell surface, resulting in effective protection against multiple external stress stimuli. The applicability of GSH as a new and effective protective agent can improve the stability and viability of various probiotics with anti-freezing and anti-thawing effects. Full article

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18 pages, 5288 KiB

Open AccessArticle

Roe Deer Produce Less Methane and Harbor Distinct Gut Microbiota

by Yu Han, Songze Li, Ruina Mu, Fei Zhao, Xiaogang Yan, Huazhe Si and Zhipeng Li

Fermentation 2023, 9(2), 186; https://doi.org/10.3390/fermentation9020186 - 17 Feb 2023

Cited by 1 | Viewed by 2119

Abstract

Enteric methane (CH₄) is an important greenhouse gas emitted by ruminants. Cervidae produces less CH₄ than other ruminants, but the underlying mechanism remains unclear. Here, we measured and compared the gas production, nutrient digestibility, gut microbiota composition, and fermentation characteristics [...] Read more.

Enteric methane (CH₄) is an important greenhouse gas emitted by ruminants. Cervidae produces less CH₄ than other ruminants, but the underlying mechanism remains unclear. Here, we measured and compared the gas production, nutrient digestibility, gut microbiota composition, and fermentation characteristics of roe deer (n = 4) and goats (n = 4). After the animals had adapted to the same total mixed ration for 21 days, the gas yield was measured using respiration chambers, and fecal samples were collected. The CH₄ yield (g/kg DMI) was significantly lower in roe deer than in goats (p < 0.001), while the difference in carbon dioxide yield was not significant (p > 0.05). Roe deer showed lower digestibility of dry matter (p = 0.005), crude protein (p < 0.001), and neutral detergent fiber (p = 0.02) than goats. Principal coordinate analysis revealed that the bacterial and methanogen communities were significantly different between roe deer and goats, indicating a potential role of host genetics. Roe deer and goats showed enrichment of specific key bacterial and methanogen taxa. The relative abundances of Bifidobacterium, Ruminococcus, Succinivibrio, Treponema, Prevotella, Lachnoclostridium, Christensenellaceae R7, and members of the family Lachnospiraceae were higher in roe deer than in goats (p < 0.05). Methanocorpusculum and Methanobrevibacter were dominant methanogens in the guts of roe deer and goats, respectively, but their species compositions differed significantly between the host species. The predicted metabolic pathways, including those for butyrate and propionate, were significantly more abundant in roe deer than in goats (p < 0.05). The molar proportions of propionate and branched volatile fatty acids were significantly higher in roe deer and goats (p < 0.01), respectively. The variation in CH₄ yield was characterized by correlations between digestibility, bacteria and methanogens between roe deer and goats, particularly for members within the taxa Lachnospiraceae and Methanosphaera. In summary, our results revealed that gut bacteria and methanogens differ significantly between high- and low-CH₄ emitters and identified microbial taxa potentially involved in the mitigation of CH₄ production in ruminants. Full article

(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)

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11 pages, 1485 KiB

Open AccessArticle

Isolation, Purification, and Antitumor Activity of a Novel Active Protein from Antrodia cinnamomea Liquid Fermentation Mycelia

by Yingying Li, Jiaxin Ge, Yanbin Li, Siqi Zheng, Yangyang Liu, Yunxiang Liang and Yuxia Mei

Fermentation 2023, 9(2), 185; https://doi.org/10.3390/fermentation9020185 - 17 Feb 2023

Cited by 2 | Viewed by 2060

Abstract

Antrodia cinnamomea, a rare medicinal fungus endemic to Taiwan, contains numerous active components and displays strong antitumor and anti-inflammatory effects. We isolated and purified a novel A. cinnamomea active protein (termed ACAP) from liquid fermentation mycelia and evaluated its antitumor activity. A [...] Read more.

Antrodia cinnamomea, a rare medicinal fungus endemic to Taiwan, contains numerous active components and displays strong antitumor and anti-inflammatory effects. We isolated and purified a novel A. cinnamomea active protein (termed ACAP) from liquid fermentation mycelia and evaluated its antitumor activity. A homogeneous protein-eluted fraction was obtained by anion exchange chromatography and gel filtration chromatography, and ACAP was identified based on the antitumor activity screening of this fraction. An in vitro assay of three tumor cell lines (HeLa, Hep G2, and Hepa 1-6) revealed significant antiproliferative effects of ACAP at low concentrations, with IC₅₀ values of 13.10, 10.70, and 18.69 µg/mL, respectively. Flow cytometric analysis showed that ACAP induced late apoptosis of Hep G2 cells. The apoptosis rate of 50 µg/mL ACAP-treated cells (60%) was significantly (p < 0.01) more than that of the control. A Western blotting assay of apoptotic pathway proteins showed that ACAP significantly upregulated p53 and downregulated caspase-3 expression levels. Our findings indicate that ACAP has strong antitumor activity and the potential for development as a therapeutic agent and/or functional food. Full article

(This article belongs to the Special Issue Bioactive Products from Edible and Medicinal Fungi by Fermentation)

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20 pages, 1386 KiB

Open AccessReview

Alcohol-Induced Headache with Neuroinflammation: Recent Progress

by He Zhu, Yanxia Xing, Otobong D. Akan and Tao Yang

Fermentation 2023, 9(2), 184; https://doi.org/10.3390/fermentation9020184 - 17 Feb 2023

Cited by 5 | Viewed by 6081

Abstract

Ethanol and other congeners in alcoholic beverages and foods are known triggers of alcohol-induced headaches (AIHs). Recent studies implicate AIHs as an important underlying factor for neuroinflammation. Studies show the relationship between alcoholic beverages, AIH agents, neuroinflammation, and the pathway they elicit. However, [...] Read more.

Ethanol and other congeners in alcoholic beverages and foods are known triggers of alcohol-induced headaches (AIHs). Recent studies implicate AIHs as an important underlying factor for neuroinflammation. Studies show the relationship between alcoholic beverages, AIH agents, neuroinflammation, and the pathway they elicit. However, studies elucidating specific AIH agents’ pathways are scarce. Works reviewing their pathways can give invaluable insights into specific substances’ patterns and how they can be controlled. Hence, we reviewed the current understanding of how AIH agents in alcoholic beverages affect neuroinflammation and their specific roles. Ethanol upregulates transient receptor potential cation channel subfamily V member 1 (TRPV1) and Toll-like receptor 4 (TLR4) expression levels; both receptors trigger a neuroinflammation response that promotes AIH manifestation—the most common cause of AIHs. Other congeners such as histamine, 5-HT, and condensed tannins also upregulate TRPV1 and TLR4, neuroinflammatory conditions, and AIHs. Data elucidating AIH agents, associating pathways, and fermentation parameters can help reduce or eliminate AIH inducers and create healthier beverages. Full article

(This article belongs to the Special Issue The Rendering of Traditional Fermented Foods in Human Diet: Distribution of Health Benefits and Nutritional Benefits)

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17 pages, 2479 KiB

Open AccessArticle

The Effects of Nanoparticles- Zerovalent Iron on Sustainable Biomethane Production through Co-Digestion of Olive Mill Wastewater and Chicken Manure

by Khalideh Al Bkoor Alrawashdeh, Kamel K. Al-Zboon, Jalal A. Al-Tabbal, La’aly A. AL-Samrraie, Abeer Al Bsoul, Rebhi A. Damseh, Ayat Khasawneh, Yasser Dessouky, Kareem Tonbol, Bassma M. Ali and Elen E. Youssef

Fermentation 2023, 9(2), 183; https://doi.org/10.3390/fermentation9020183 - 17 Feb 2023

Cited by 4 | Viewed by 2217

Abstract

The impacts of nanoparticles-zerovalent iron (NP-ZVI) on anaerobic co-digestion (AcoD) were assessed. The production of biogas and methane (CH₄), as well as the removal efficiency of volatile solids (VS) and contaminants were investigated in the AcoD of chicken manure (CM) and [...] Read more.

The impacts of nanoparticles-zerovalent iron (NP-ZVI) on anaerobic co-digestion (AcoD) were assessed. The production of biogas and methane (CH₄), as well as the removal efficiency of volatile solids (VS) and contaminants were investigated in the AcoD of chicken manure (CM) and olive mill wastewater (OMWW) with the addition of NP-ZVI at different concentrations (10–50 mg/g VS) and different sizes resulting from various mixing volume ratios (MVR) of NaBH₄:FeSO₄.7H₂O. The results show that NP-ZVI ≤ 30 mg/g VS at MVR-2:1, MVR-4:1, and MVR-6:1 improves the AcoD. In contrast to 40–50 mg/g VS of NP-ZVI, which caused an inhibitory impact in all of the AcoD stages, as well as a decrease in the contaminant’s removal efficiency, the concentration of 10–30 mg NP-ZVI/g VS at MVR-4:1 achieved a maximum improvement of CH₄ by 21.09%, 20.32%, and 22.87%, respectively, and improved the biogas by 48.14%, 55.0%, and 80.09%, respectively, vs. the 0 additives. Supplementing AcoD with NP-ZVI at a concentration of 30 mg/g VS at MVR-4:1 resulted in maximum enhancement of the contaminant removal efficiency, with a total oxygen demand (TCOD) of up to 73.99%, turbidity up to 79.07%, color up to 53.41%, total solid (TS) up to 59.57%, and volatile solid (VS) up to 74.42%. It also improved the hydrolysis and acidification percentages by up to 86.67% and 51.3%, respectively. Full article

(This article belongs to the Special Issue Energy Converter: Anaerobic Digestion)

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22 pages, 2230 KiB

Open AccessArticle

Assessment of Starters of Lactic Acid Bacteria and Killer Yeasts: Selected Strains in Lab-Scale Fermentations of Table Olives (Olea europaea L.) cv. Leccino

by Grazia Federica Bencresciuto, Claudio Mandalà, Carmela Anna Migliori, Giovanna Cortellino, Maristella Vanoli and Laura Bardi

Fermentation 2023, 9(2), 182; https://doi.org/10.3390/fermentation9020182 - 17 Feb 2023

Cited by 8 | Viewed by 2459

Abstract

Olives debittering, organoleptic quality and safety can be improved with yeasts and lactic acid bacteria (LABs) selected strain starters, that allow for better fermentation control with respect to natural fermentation. Two selected killer yeasts (Wickerhamomyces anomalus and Saccharomyces cerevisiae) and Lactobacillus [...] Read more.

Olives debittering, organoleptic quality and safety can be improved with yeasts and lactic acid bacteria (LABs) selected strain starters, that allow for better fermentation control with respect to natural fermentation. Two selected killer yeasts (Wickerhamomyces anomalus and Saccharomyces cerevisiae) and Lactobacillus plantarum strains were tested for olive (cv. Leccino) fermentation to compare different starter combinations and strategies; the aim was to assess their potential in avoiding pretreatments and the use of excessive salt in the brines and preservatives. Lactobacilli, yeasts, molds, Enterobacteriaceae and total aerobic bacteria were detected, as well as pH, soluble sugars, alcohols, organic acids, phenolic compounds, and rheological properties of olives. Sugars were rapidly consumed in the brines and olives; the pH dropped quickly, then rose until neutrality after six months. The oleuropein final levels in olives were unaffected by the treatments. The use of starters did not improve the LABs’ growth nor prevent the growth of Enterobacteriaceae and molds. The growth of undesirable microorganisms could have been induced by the availability of selective carbon source such as mannitol, whose concentration in olive trees rise under drought stress. The possible role of climate change on the quality and safety of fermented foods should be furtherly investigated. The improvement of olives’ nutraceutical value can be induced by yeasts and LABs starters due to the higher production of hydroxytyrosol. Full article

(This article belongs to the Special Issue Yeast Biotechnology 6.0)

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14 pages, 1539 KiB

Open AccessArticle

Evaluation of Fermentative Xylitol Production Potential of Adapted Strains of Meyerozyma caribbica and Candida tropicalis from Rice Straw Hemicellulosic Hydrolysate

by Sundeep Kaur, Payal Guleria and Sudesh Kumar Yadav

Fermentation 2023, 9(2), 181; https://doi.org/10.3390/fermentation9020181 - 16 Feb 2023

Cited by 9 | Viewed by 2722

Abstract

Dilute acid hydrolysis of lignocellulosic biomass generates inhibitors in the hydrolysate which hamper yeast metabolism and the fermentation process. Therefore, understanding the effect of these compounds on the performance of microorganisms becomes essential to achieve improved product yields. In this study, the effect [...] Read more.

Dilute acid hydrolysis of lignocellulosic biomass generates inhibitors in the hydrolysate which hamper yeast metabolism and the fermentation process. Therefore, understanding the effect of these compounds on the performance of microorganisms becomes essential to achieve improved product yields. In this study, the effect of acetic acid, furfural, and hydroxymethylfurfural was evaluated on yeast growth and fermentation efficiency. Various parameters for the pretreatment of rice straw, such as an acid catalyst, and its concentration and residence time, were optimized for the maximum liberation of sugars in the hydrolysate. Further, the yeast strains Candida tropicalis and Meyerozyma caribbica were adapted for the tolerance of inhibitors at higher concentrations. A comparative analysis was carried out using un-adapted and adapted strains of Candida tropicalis and Meyerozyma caribbica for xylitol production. The findings of this study revealed that sulfuric acid (1.25% v/v) at 121 ரC for 30 min can efficiently convert rice straw xylan to xylose, with the release of 16.07 g/L xylose in the hydrolysate. Further, the adaptation results showed an increase of 76.42% and 69.33% in xylose assimilation by C. tropicalis and M. caribbica, respectively. The xylitol production with the adapted C. tropicalis was increased by 7.54% to 28.03 g/L xylitol. However, the xylitol production with the adapted M. caribbica was increased by 8.33%, yielding 26.02 g/L xylitol in the non-detoxified hydrolysate when compared to the un-adapted strains. Repeated batch fermentation was carried out for seven batches, and xylitol was found to be efficiently produced by the yeasts during five successive batches without any significant loss in the xylitol yield. Moreover, the results suggest that M. caribbica is a promising microorganism for the transformation of rice straw-derived xylose to xylitol. Full article

(This article belongs to the Section Industrial Fermentation)

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22 pages, 1270 KiB

Open AccessArticle

Optimization of Wheat Straw Conversion into Microbial Lipids by Lipomyces tetrasporus DSM 70314 from Bench to Pilot Scale

by Antonio Caporusso, Isabella De Bari, Aristide Giuliano, Federico Liuzzi, Roberto Albergo, Rocchina Pietrafesa, Gabriella Siesto, Assunta Romanelli, Giacobbe Braccio and Angela Capece

Fermentation 2023, 9(2), 180; https://doi.org/10.3390/fermentation9020180 - 16 Feb 2023

Cited by 7 | Viewed by 2340

Abstract

Microbial lipids are renewable platforms for several applications including biofuels, green chemicals, and nutraceuticals that can be produced from several residual carbon sources. Lignocellulosic biomasses are abundant raw materials for the production of second-generation sugars with conversion yields depending on the quality of [...] Read more.

Microbial lipids are renewable platforms for several applications including biofuels, green chemicals, and nutraceuticals that can be produced from several residual carbon sources. Lignocellulosic biomasses are abundant raw materials for the production of second-generation sugars with conversion yields depending on the quality of the hydrolysates and the metabolic efficiency of the microorganisms. In the present work, wheat straw pre-treated by steam explosion and enzymatically hydrolysed was converted into microbial lipids by Lipomyces tetrasporus DSM 70314. The preliminary optimization of the enzymatic hydrolysis was performed at the bench scale through the response surface methodology (RSM). The fermentation medium and set-up were optimized in terms of the nitrogen (N) source and carbon-to-nitrogen (C/N) ratio yielding to the selection of soy flour as a N source and C/N ratio of 160. The bench scale settings were scaled-up and further optimized at the 10 L-scale and finally at the 50 L pilot scale bioreactor. Process optimization also included oxygen supply strategies. Under optimized conditions, a lipid concentration of 14.8 gL⁻¹ was achieved corresponding to a 23.1% w/w lipid yield and 67.4% w/w lipid cell content. Oleic acid was the most abundant fatty acid with a percentage of 57%. The overall process mass balance was assessed for the production of biodiesel from wheat straw. Full article

(This article belongs to the Special Issue Recent Trend in Biofuel Fermentation from Renewable Biomass)

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20 pages, 2753 KiB

Open AccessArticle

Laccase Production from Local Biomass Using Solid State Fermentation

by Shoaib Hasan, Zahid Anwar, Waseem Khalid, Fareed Afzal, Muddassar Zafar, Usman Ali, Mohammed Y. Refai, Mohamed Afifi, Ammar AL-Farga and Moneera O. Aljobair

Fermentation 2023, 9(2), 179; https://doi.org/10.3390/fermentation9020179 - 16 Feb 2023

Cited by 11 | Viewed by 3635

Abstract

The large family of enzymes, known as polyphenols oxidases, includes laccase. Due to the inclusion of a copper atom in their catalytic core, laccases are frequently referred to as multi-copper oxidases. Laccases are versatile enzymes that can catalyze the oxidation of a wide [...] Read more.

The large family of enzymes, known as polyphenols oxidases, includes laccase. Due to the inclusion of a copper atom in their catalytic core, laccases are frequently referred to as multi-copper oxidases. Laccases are versatile enzymes that can catalyze the oxidation of a wide range of phenolic and non-phenolic substances. In the current study, a local strain of Aspergillus niger was used for solid-state fermentation to produce fungal laccase, as well as purify and optimize laccase. The enzyme profile, which was acquired using guaiacol to measure enzyme activity, showed that after five days of incubation, wheat straw provided the highest level of laccase activity, or 2.551 U/mL. A technique called response surface methodology (RSM) was used to examine the effects of various conditions on the production of enzymes. The RSM results demonstrated that after five days of incubation, the enzyme activity was at its highest at 45 °C, pH 5.5, and 30% moisture level, inoculated with 2 mL mycelium. Through ammonium sulphate precipitation and dialysis, the enzyme was purified. Additionally, column chromatography was used to further purify laccase. The next step was enzyme characterization to evaluate how temperature and pH affected enzyme activity. At 45 °C and pH 5.5, the isolated enzyme produced its highest level of activity. The findings of the current study showed that A. niger is capable of producing laccase in an economical and environmentally friendly way. Due to its unique oxidative and catalytic features, this enzyme has received a lot of attention recently. Full article

(This article belongs to the Section Industrial Fermentation)

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8 pages, 1134 KiB

Open AccessCommunication

Effect of Ammonia–Autoclave Pretreatment on the Performance of Corn Straw and Cow Manure Batch Anaerobic Digestion

by Yonghua Xu, Xinrui Xu, Xiaohong Su, Wei Liu, Jingbo Qu and Yong Sun

Fermentation 2023, 9(2), 178; https://doi.org/10.3390/fermentation9020178 - 16 Feb 2023

Viewed by 1626

Abstract

Biomass pretreatment is a critical method for improving the anaerobic digestion (AD) performance of lignocellulosic feedstocks. In this study, an effective combined ammonia–autoclave pretreatment method was selected for the pretreatment of corn straw at 90 °C using four ammonia concentrations (7%, 9%, 11%, [...] Read more.

Biomass pretreatment is a critical method for improving the anaerobic digestion (AD) performance of lignocellulosic feedstocks. In this study, an effective combined ammonia–autoclave pretreatment method was selected for the pretreatment of corn straw at 90 °C using four ammonia concentrations (7%, 9%, 11%, and 13%). The results showed that the combined pretreatment improved the substrate’s degradation efficiency and the system’s buffer capacity, and significantly improved the hydrolysis and biogas production performance of corn straw. After pretreatment, the lignin removal rate increased by 11.28–39.69%, and the hemicellulose degradation rate increased from 10.12% to 21.23%. Pretreatment of corn straw with 9% ammonia and an autoclave gave the highest methane yield of 257.11 mL/gVS, which was 2.32-fold higher than that of untreated corn straw, making it the optimal pretreatment condition for corn straw. Therefore, the combined ammonia–autoclave pretreatment technology can further improve the AD performance of corn straw. Full article

(This article belongs to the Section Industrial Fermentation)

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14 pages, 3923 KiB

Open AccessArticle

Ammonia–Mechanical Pretreatment of Wheat Straw for the Production of Lactic Acid and High-Quality Lignin

by Yulian Cao, Haifeng Liu, Junqiang Shan, Baijun Sun, Yanjun Chen, Lei Ji, Xingxiang Ji, Jian Wang, Chenjie Zhu and Hanjie Ying

Fermentation 2023, 9(2), 177; https://doi.org/10.3390/fermentation9020177 - 15 Feb 2023

Cited by 3 | Viewed by 2333

Abstract

In this study, wheat straw was fractionated into carbohydrates (cellulose and hemicellulose) by ammonia–mechanical pretreatment for l-lactic acid fermentation. Under optimal conditions (aqueous ammonia concentration: 19% w/w, liquid–solid ratio: 2.1:1 w/w, holding time: 4.80 h), the delignification was more than [...] Read more.

In this study, wheat straw was fractionated into carbohydrates (cellulose and hemicellulose) by ammonia–mechanical pretreatment for l-lactic acid fermentation. Under optimal conditions (aqueous ammonia concentration: 19% w/w, liquid–solid ratio: 2.1:1 w/w, holding time: 4.80 h), the delignification was more than 60%. After enzymatic hydrolysis, the maximum conversions of cellulose and hemicellulose were 92.5% and 83.4% based on the pretreatment residue, respectively. The wheat straw hydrolysate was used to produce l-lactic acid with Thermoanaerobacter sp. DH-217G, which obtained a yield of 88.6% and an optical purity of 99.2%. The ammonia–mechanical pretreatment is an economical method for the production of fermentable monosaccharide, providing potential for further downstream high value-added applications. Full article

(This article belongs to the Special Issue Lignocellulosic Biorefineries and Downstream Processing)

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19 pages, 3948 KiB

Open AccessArticle

Cellulosic Fiber Waste Feedstock for Bioethanol Production via Bioreactor-Dependent Fermentation

by Ahmed E. Mansy, Eman El-Desouky, Hamada El-Gendi, Mohamed A. Abu-Saied, Tarek H. Taha and Ranya A. Amer

Fermentation 2023, 9(2), 176; https://doi.org/10.3390/fermentation9020176 - 15 Feb 2023

Cited by 4 | Viewed by 2497

Abstract

The bioconversion of environmental wastes into energy is gaining much interest in most developing and developed countries. The current study is concerned with the proper exploitation of some industrial wastes. Cellulosic fiber waste was selected as a raw material for producing bioethanol as [...] Read more.

The bioconversion of environmental wastes into energy is gaining much interest in most developing and developed countries. The current study is concerned with the proper exploitation of some industrial wastes. Cellulosic fiber waste was selected as a raw material for producing bioethanol as an alternative energy source. A combination of physical, chemical, and enzymatic hydrolysis treatments was applied to maximize the concentration of glucose that could be fermented with yeast into bioethanol. The results showed that the maximum production of 13.9 mg/mL of glucose was achieved when 5% cellulosic fiber waste was treated with 40% HCl, autoclaved, and followed with enzymatic hydrolysis. Using SEM and FTIR analysis, the instrumental characterization of the waste fiber treatment confirmed the effectiveness of the degradation by turning the long threads of the fibers into small pieces, in addition to the appearance of new functional groups and peak shifting. A potent yeast strain isolated from rotten grapes was identified as Starmerella bacillaris STDF-G4 (accession number OP872748), which was used to ferment the obtained glucose units into bioethanol under optimized conditions. The maximum production of 3.16 mg/mL of bioethanol was recorded when 7% of the yeast strain was anaerobically incubated at 30 °C in a broth culture with the pH adjusted to 5. The optimized conditions were scaled up from flasks to a fermentation bioreactor to maximize the bioethanol concentration. The obtained data showed the ability of the yeast strain to produce 4.13 mg/mL of bioethanol after the first 6 h of incubation and double the amount after 36 h of incubation to reach 8.6 mg/mL, indicating the efficiency of the bioreactor in reducing the time and significantly increasing the product. Full article

(This article belongs to the Special Issue Bioelectrochemical System for Bioenergy and Bioproducts Recovery (BBB))

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11 pages, 2783 KiB

Open AccessArticle

Development of Digested Sludge-Assimilating and Biohydrogen-Yielding Microflorae

by Yuhei Hayakawa, Nobuhiro Aburai and Katsuhiko Fujii

Fermentation 2023, 9(2), 175; https://doi.org/10.3390/fermentation9020175 - 15 Feb 2023

Cited by 3 | Viewed by 1556

Abstract

Digested sludge (DS) is a waste product of anaerobic digestion that is produced during the biodegradation of excess sludge. It cannot be used as a substrate for further biogas production owing to its recalcitrant nature. In the present study, we used a heat [...] Read more.

Digested sludge (DS) is a waste product of anaerobic digestion that is produced during the biodegradation of excess sludge. It cannot be used as a substrate for further biogas production owing to its recalcitrant nature. In the present study, we used a heat treatment technique to convert DABYS microflora (DABYS = digested sludge-assimilating and biogas-yielding soil microflora), which degraded DS and produced methane gas, to a microflora that could produce hydrogen gas from DS. Heat treatment at 80 and 100 °C inactivated the methanogens that consume hydrogen for methane production but did not affect the thermotolerant bacteria. We developed three microflorae (DABYS-A80, DABYS-A100, and DABYS-80B) to exclusively produce hydrogen gas. They included representatives from the anaerobic eubacterial families Clostridiaceae and Enterobacteriaceae. Pseudomonas sp. was also present in DABYS-A80 and DABYS-A100. It is thought that bacteria in the Enterobacteriaceae family or Pseudomonas genus survive heat treatment because they are embedded in microgranules. Enzymatic analysis suggested that the microflorae hydrolyzed DS using cellulase, chitinase, and protease. Under optimum culture conditions, DABYS-A80, -A100, and B-100 produced gas yields of 8.0, 7.1, and 2.6 mL, respectively, from 1.0 g of dried DS. Full article

(This article belongs to the Special Issue Anaerobic Fermentation of Organic Waste Materials and Valorisation)

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12 pages, 1027 KiB

Open AccessArticle

Characterization of Bee Bread Produced with Defined Starter Cultures Mimicking the Natural Fermentation Process

by Fatmanur Poyraz, Dilara Yalmanci, Hümeyra İspirli and Enes Dertli

Fermentation 2023, 9(2), 174; https://doi.org/10.3390/fermentation9020174 - 15 Feb 2023

Cited by 9 | Viewed by 3664

Abstract

Bee bread is a product with unique properties for humans and bees that is produced through the fermentation of pollen in the honeycomb, mainly caused by lactic acid bacteria (LAB) and yeast strains present in the environment. It is a rich source of [...] Read more.

Bee bread is a product with unique properties for humans and bees that is produced through the fermentation of pollen in the honeycomb, mainly caused by lactic acid bacteria (LAB) and yeast strains present in the environment. It is a rich source of nutrients such as proteins, polyphenols and vitamins. Despite the potential nutritional value of bee bread, it is consumed at low levels, as harvesting bee bread from the hives is costly and difficult. This study aimed to produce a standard bee bread by using different strains of the fructophilic lactic acid bacteria (FLAB) Lactobacillus kunkeei and the yeasts Starmeralla magnolia MP-2 and Zygosaccharomyces siamensis MP-14, previously isolated from bee products. In this context, bee bread was produced from pollen by solid-state fermentation using selected FLAB and yeast species, which were then compared with spontaneously developed and commercially available bee bread in terms of microbial stability, physicochemical properties, total phenolic component amounts, in vitro digestibility and amino acid profiles. As a result, it was determined that bee bread made from bee pollen fermented with starter cultures showed improved characteristics than commercial bee bread and was more advantageous in terms of absorption as well as production processes. Full article

(This article belongs to the Special Issue Microbial Biotechnology and Agro-Industrial By-Products Fermentation)

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14 pages, 4377 KiB

Open AccessEditor’s ChoiceArticle

Changes in Physicochemical Characteristics and Microbial Diversity of Traditional Fermented Vinasse Hairtail

by Yue Zhang, Chuanhai Tu, Huimin Lin, Yuwei Hu, Junqi Jia, Shanshan Shui, Jiaxing Wang, Yi Hu and Bin Zhang

Fermentation 2023, 9(2), 173; https://doi.org/10.3390/fermentation9020173 - 14 Feb 2023

Cited by 6 | Viewed by 2074

Abstract

Fermented foods may confer several benefits to human health and play an important role in a healthy and balanced diet. Vinasse hairtail is a farmhouse-fermented food product with cultural and economic significance to locals in Zhoushan China. It is traditionally produced and subjected [...] Read more.

Fermented foods may confer several benefits to human health and play an important role in a healthy and balanced diet. Vinasse hairtail is a farmhouse-fermented food product with cultural and economic significance to locals in Zhoushan China. It is traditionally produced and subjected to 0–8 days of fermentation. In this study, we aimed to characterize the microbiota and physicochemical profiles of vinasse hairtail across different stages of fermentation. With the increase of fermentation time, pH, total sugar content, reducing sugar content, fat content, salt content, total protein content, myofibrillar protein content, TVB-N, and TBARS index increased, while the peroxide value decreased. The addition of vinasse significantly intensified the lipid and protein oxidation and protein degradation of hairtail, thereby increasing the flavor of its products. The microbial diversity and succession characterization during the fermentation of vinasse hairtail by high-throughput sequencing was measured. Results showed that Firmicutes was the predominant phylum and Lactobacillus was the main genera of bacterial diversity. Ascomycota was the main phylum of fungi and the main fungal genera detected in the samples were Saccharomyces. Additionally, the correlation between microbial community and physicochemical properties was found. Our study revealed that Lactobacillus was the major lactic acid bacteria present throughout the fermentation process. The results may provide a theoretical basis for improving the overall quality of vinasse hairtail. Full article

(This article belongs to the Special Issue Microbial Resources and Health Effects of Traditional Fermented Food)

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17 pages, 2873 KiB

Open AccessArticle

A Genome-Wide Phenotypic Analysis of Saccharomyces cerevisiae’s Adaptive Response and Tolerance to Chitosan in Conditions Relevant for Winemaking

by Patrícia Lage, Bárbara B. Coelho, Nuno P. Mira and Ana Mendes-Ferreira

Fermentation 2023, 9(2), 172; https://doi.org/10.3390/fermentation9020172 - 14 Feb 2023

Cited by 1 | Viewed by 2306

Abstract

In the wine industry, the use of chitosan, a non-toxic biodegradable polysaccharide with antimicrobial properties, has been gaining interest with respect to envisaging the reduction in the use of sulfur dioxide (SO₂). Although the mechanisms of toxicity of chitosan against fungal [...] Read more.

In the wine industry, the use of chitosan, a non-toxic biodegradable polysaccharide with antimicrobial properties, has been gaining interest with respect to envisaging the reduction in the use of sulfur dioxide (SO₂). Although the mechanisms of toxicity of chitosan against fungal cells have been addressed before, most of the studies undertaken used other sources of chitosan and/or used conditions to solubilize the polymer that were not compatible with winemaking. Herein, the effect of a commercial formulation of chitosan approved for use in winemaking over the growth of the spoilage yeast species Dekkera anomala, Saccharomycodes ludwigii, Zygosaccharomyces bailii, and Pichia anomala was assessed. At the legally allowed concentration of 0.1 g/L, chitosan inhibited the growth of all spoilage yeasts, except for the tested Pichia anomala strains. Interestingly, the highly SO₂-tolerant yeasts S. ludwigii and Z. bailii were highly susceptible to chitosan. The growth of commercial Saccharomyces cerevisiae was also impacted by chitosan, in a strain-dependent manner, albeit at higher concentrations. To dissect this differential inhibitory potential and gain further insight into the interaction of chitosan over fungal cells, we explored a chemogenomic analysis to identify all of the S. cerevisiae genes conferring protection against or increasing susceptibility to the commercial formulation of chitosan. Among the genes found to confer protection against chitosan, a high proportion was found to encode proteins required for the assembly and structuring of the cell wall, enzymes involved in the synthesis of plasma membrane lipids, and components of signaling pathways that respond to damages in the plasma membrane (e.g., the Rim101 pathway). The data obtained also suggest that the fungal ribosome and the vacuolar V-ATPase could be directly targeted by chitosan, since the deletion of genes encoding proteins required for the structure and function of these organelles was found to increase tolerance to chitosan. We also demonstrated, for the first time, that the deletion of ITR1, AGP2 and FPS1, encoding plasma membrane transporters, prominently increased the tolerance of S. cerevisiae to chitosan, suggesting that they can serve as carriers for chitosan. Besides providing new insights into the mode of action of chitosan against wine yeasts, this study adds relevant information for its rational use as a substitute/complementary preservative to SO₂. Full article

(This article belongs to the Special Issue Wine Microbiology)

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18 pages, 2905 KiB

Open AccessArticle

Production of Pigments under Submerged Culture through Repeated Batch Fermentation of Immobilized Talaromyces atroroseus GH2

by Juan Pablo Ruiz-Sánchez, Lourdes Morales-Oyervides, Daniele Giuffrida, Laurent Dufossé and Julio César Montañez

Fermentation 2023, 9(2), 171; https://doi.org/10.3390/fermentation9020171 - 14 Feb 2023

Cited by 6 | Viewed by 2393

Abstract

Pigments of natural origin have become a research trend, and fungi provide a readily available alternative source. Moreover, developing novel processes that increase yields, reduce process time and simplify downstream processing is of increased interest. In this sense, this work proposes an alternative [...] Read more.

Pigments of natural origin have become a research trend, and fungi provide a readily available alternative source. Moreover, developing novel processes that increase yields, reduce process time and simplify downstream processing is of increased interest. In this sense, this work proposes an alternative for Talaromyces atroroseus GH2 biomass re-utilization to produce pigments through consecutive batches using immobilized mycelium. Different support materials were evaluated for pigment production and immobilization capacity. Then, Taguchi’s method was applied to determine the effect of four factors related to fungal immobilization and pigment production (inoculum concentration, support density, working volume and support volume). Afterward, process kinetics for pigment production using immobilized cells of T. atroroseus GH2 in consecutive batches were evaluated. All evaluated factors were significant and affected pigment production and microorganism growth differently. At improved conditions, immobilization capacity reached 99.01 ± 0.37% and the pigment production was 30% higher than using free cells. Process kinetics showed that the production could continue for three batches and was limited by excessive microorganism growth. Indeed, more studies are still needed, but the immobilization of Talaromyces atroroseus GH2 represents a promising strategy for allowing downstream-processing intensification since immobilized biomass is easily removed from the fermentation media, thus paving the way for the further development of a continuous process. Full article

(This article belongs to the Special Issue Pigment Production in Submerged Fermentation)

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11 pages, 1289 KiB

Open AccessEditor’s ChoiceArticle

High-Gravity Fermentation for Bioethanol Production from Industrial Spent Black Cherry Brine Supplemented with Whey

by Javier Ricardo Gómez Cardozo, Jean-Baptiste Beigbeder, Julia Maria de Madeiros Dantas and Jean-Michel Lavoie

Fermentation 2023, 9(2), 170; https://doi.org/10.3390/fermentation9020170 - 14 Feb 2023

Viewed by 2960

Abstract

By-products from different industries could represent an available source of carbon and nitrogen which could be used for bioethanol production using conventional Saccharomyces cerevisiae yeast. Spent cherry brine and whey are acid food by-products which have a high organic matter content and toxic [...] Read more.

By-products from different industries could represent an available source of carbon and nitrogen which could be used for bioethanol production using conventional Saccharomyces cerevisiae yeast. Spent cherry brine and whey are acid food by-products which have a high organic matter content and toxic compounds, and their discharges represent significant environmental and economic challenges. In this study, different combinations of urea, yeast concentrations, and whey as a nutrient source were tested for bioethanol production scale-up using 96-well microplates as well as 7.5 L to 100 L bioreactors. For bioethanol production in vials, the addition of urea allowed increasing the bioethanol yield by about 10%. Bioethanol production in the 7.5 L and 100 L bioreactors was 73.2 g·L⁻¹ and 103.5 g·L⁻¹ with a sugar consumption of 81.5% and 94.8%, respectively, using spent cherry brine diluted into whey (200 g·L⁻¹ of total sugars) supplemented with 0.5 g·L⁻¹ urea and 0.5 g·L⁻¹ yeast at 30 °C and a pH of 5.0 after 96 h of fermentation for both systems. The results allow these by-products to be considered low-economic-value alternatives for fuel- or food-grade bioethanol production. Full article

(This article belongs to the Special Issue Yeast, Biofuels, and Value-Added Products)

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12 pages, 1685 KiB

Open AccessArticle

H₂S Emission and Microbial Community of Chicken Manure and Vegetable Waste in Anaerobic Digestion: A Comparative Study

by Guangliang Tian, Marvin Yeung and Jinying Xi

Fermentation 2023, 9(2), 169; https://doi.org/10.3390/fermentation9020169 - 13 Feb 2023

Cited by 4 | Viewed by 1703

Abstract

In order to solve the problem of H₂S corrosion in biogas utilization, it is necessary to understand the characteristics and mechanisms of H₂S production in chicken manure anaerobic digestion (CMAD) and vegetable waste anaerobic digestion (VWAD). In this study, [...] Read more.

In order to solve the problem of H₂S corrosion in biogas utilization, it is necessary to understand the characteristics and mechanisms of H₂S production in chicken manure anaerobic digestion (CMAD) and vegetable waste anaerobic digestion (VWAD). In this study, lab-scale batch tests of CMAD and VWAD were conducted for 67 days at 35 °C. The results showed that sulfide was found to be the major form of sulfur in CMAD (accounting for 90%) and VWAD (70%). The average concentration of H₂S was 198 ± 79 ppm in CMAD and 738 ± 210 ppm in VWAD. Moreover, 81% of total H₂S was produced at 20 days of methane production in CMAD, but 80% of total H₂S was produced in the first day in VWAD because of the rapid production of biogas and fermentation acidification. The sulfide ion equilibrium model could universally and feasibly predict the H₂S production in CMAD and VWAD. The abundance of Firmicutes, Bacteroidetes, Proteobacteria and Euryarchaeota accounted for about 95% of the total microbes in both CMAD and VWAD; the influence of the fermentation stage on the microbial community was greater than that of the difference between CM and VW; the abundance of SRB was 0.01~0.07%, while that concerning organosulfur compounds fermentation was 22.8~30.5%. This study indicated that the H₂S concentration of CMAD biogas was more than five times that of VWAD because CM is alkalescent but VW is acidic. Full article

(This article belongs to the Section Industrial Fermentation)

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14 pages, 1554 KiB

Open AccessArticle

Monascus Yellow Pigment Production by Coupled Immobilized-Cell Fermentation and Extractive Fermentation in Nonionic Surfactant Micelle Aqueous Solution

by Kan Shi, Yuzhu Zhao, Da Song, Gong Chen, Chengtao Wang, Zhenqiang Wu and Huawei Gu

Fermentation 2023, 9(2), 168; https://doi.org/10.3390/fermentation9020168 - 13 Feb 2023

Cited by 1 | Viewed by 2110

Abstract

Microbial fermentation with immobilized cells possesses many advantages. However, this fermentation mode is restricted to the production of extracellular products. Our previous study demonstrated that the extractive fermentation of Monascus spp. in nonionic surfactant micelle aqueous solution can export Monascus pigments that are [...] Read more.

Microbial fermentation with immobilized cells possesses many advantages. However, this fermentation mode is restricted to the production of extracellular products. Our previous study demonstrated that the extractive fermentation of Monascus spp. in nonionic surfactant micelle aqueous solution can export Monascus pigments that are supposed to be mainly intracellular products to extracellular culture broth and, in the meantime, extracellularly enhance the production of yellow pigments at a low pH condition; consequently, this makes the continuous production of yellow pigments with immobilized Monascus cells feasible. In this study, immobilized-cell fermentation and extractive fermentation in Triton X-100 micelle aqueous solution were successfully combined to continuously produce Monascus yellow pigments extracellularly. We examined the effects of cell immobilization and Triton X-100 on cell growth, pigment production, and pigment composition. In the repeated-batch extractive fermentation with immobilized cells, the biomass in Ca-alginate gel beads continued to grow and reached 21.2 g/L after seven batches, and dominant yellow pigments were produced extracellularly and stable for each batch. The mean productivity of the extracellular yellow pigments reached up to 22.31 AU_{410 nm}/day within the first four batches (13 days) and 19.7 AU_{410 nm}/day within the first seven batches (25 days). The results also provide a new strategy for producing such intracellular products continuously and extracellularly. Full article

(This article belongs to the Special Issue Pigment Production in Submerged Fermentation)

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