Fermentation

21 pages, 3556 KiB

Open AccessArticle

Food Ingredients for the Future: In-Depth Analysis of the Effects of Lactic Acid Bacteria Fermentation on Spent Barley Rootlets

by Emma Neylon, Laura Nyhan, Emanuele Zannini, Thomas Monin, Steffen Münch, Aylin W. Sahin and Elke K. Arendt

Fermentation 2023, 9(1), 78; https://doi.org/10.3390/fermentation9010078 - 16 Jan 2023

Cited by 10 | Viewed by 3436

Abstract

Repurposing by-products to alternative applications has become a vital part of food research. Barley rootlets (BRs) are a side-stream of malting and brewing industries. This study focuses on processing BRs into food ingredients, using fermentation with five lactic acid bacteria (LAB) as a [...] Read more.

Repurposing by-products to alternative applications has become a vital part of food research. Barley rootlets (BRs) are a side-stream of malting and brewing industries. This study focuses on processing BRs into food ingredients, using fermentation with five lactic acid bacteria (LAB) as a valorisation technique. The strains used were Lactiplantibacillus plantarum FST 1.7, Lactobacillus amylovorus FST2.11, Weissella cibaria MG1, Leuconostoc citreum TR116 and Limosilactobacillus reuteri R29. The influence of fermentation on sugar/FODMAP/acid compositions and microbial metabolites in BRs was analysed. A variety of techno-functional properties were also evaluated. Results showed BRs were a suitable substrate for LAB, particularly for Lactiplantibacillus plantarum FST 1.7 and Lactobacillus amylovorus FST2.11. Sugar, acid and the FODMAP composition of the fermented BRs demonstrated various traits imparted by LABs, including high mannitol production from Leuconostoc citreum TR116 and Limosilactobacillus reuteri R29. Limosilactobacillus reuteri R29 also produced fructans using BRs as a substrate. A techno-functional analysis of BRs showed a significant reduction in α-amylase activity post sterilisation and fermentation. Fermentation reduced water-binding capacity and significantly increased oil-binding capacity. The LAB used displayed great potential in improving the functionality of BRs as a food ingredient while also showcasing LAB fermentation as a viable processing aid for BR valorisation. Full article

(This article belongs to the Special Issue Bioactivity Change in Fermented Foods)

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17 pages, 4561 KiB

Open AccessEditor’s ChoiceArticle

Scale-Up of Pigment Production by the Marine-Derived Filamentous Fungus, Talaromyces albobiverticillius 30548, from Shake Flask to Stirred Bioreactor

by Mekala Venkatachalam, Gary Mares, Laurent Dufossé and Mireille Fouillaud

Fermentation 2023, 9(1), 77; https://doi.org/10.3390/fermentation9010077 - 16 Jan 2023

Cited by 5 | Viewed by 3147

Abstract

Talaromyces albobiverticillius 30548, a marine-derived fungus, produces Monascus-like azaphilone red/orange pigments which have the potential for various industrial applications. The objective of this study was to scale up pigment production in a 2 L bioreactor with a working volume of 1.3 L [...] Read more.

Talaromyces albobiverticillius 30548, a marine-derived fungus, produces Monascus-like azaphilone red/orange pigments which have the potential for various industrial applications. The objective of this study was to scale up pigment production in a 2 L bioreactor with a working volume of 1.3 L media and to compare its biomass growth and pigment production against small volume (500 mL) shake flasks with 200 mL working volume. Additionally, fungal morphology, pigment intensity, fermentation length and duration of pigment production were also compared. Experiments were carried out at laboratory scale in 200 mL shake flasks without controlling pH and oxygen. In parallel, fermentation was performed in a 2 L bioreactor as an initial scale-up to investigate the influence of dissolved oxygen, agitation speed and controlled pH on pigment production and biomass growth of T. albobiverticillius 30548. The highest orange and red pigment production in bioreactor at 24 °C was noticed after 160 h of fermentation (70% pO₂) with 25.95 AU 470 nm for orange pigments and 22.79 AU 500 nm for red pigments, at pH set point 5.0. Meanwhile, the fermentation using 200 mL shake flasks effectively produced orange pigments with 22.39 AU 470 nm and red pigments with 14.84 AU 500 nm at 192 h under the same experimental conditions (24 °C, pH 5.0, 150 rpm). Regarding fungal morphology, growth of fungus in the bioreactor was in the form of pellets, whereas in the shake flasks it grew in the form of filaments. From the observed differences in shake flasks and closed bioreactor, it is known that the bioprocess was significantly influenced by dissolved oxygen saturation and agitation speed in scale-up. Thus, oxygen transfer appears to be the rate-limiting factor, which highly influences overall growth and production of pigments in Talaromyces albobiverticillius 30548 liquid culture. Full article

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

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21 pages, 3396 KiB

Open AccessReview

The Genus Chrysosporium: A Potential Producer of Natural Products

by Yifei Wang, Xiaowen Yang, Yanjing Li, Bo Wang and Ting Shi

Fermentation 2023, 9(1), 76; https://doi.org/10.3390/fermentation9010076 - 16 Jan 2023

Cited by 2 | Viewed by 2601

Abstract

Chrysosporium, a genus of ascomycete fungi in the family Onygenaceae, has the ability to produce abundant new bioactive natural products, providing a structural foundation in drug development. This review includes the sources, distribution, biological activities and structural characteristics of the compounds [...] Read more.

Chrysosporium, a genus of ascomycete fungi in the family Onygenaceae, has the ability to produce abundant new bioactive natural products, providing a structural foundation in drug development. This review includes the sources, distribution, biological activities and structural characteristics of the compounds isolated from Chrysosporium from 1984 to 2021. The results show that 66% of the compounds isolated from Chrysosporium are new natural products. More than half of the Chrysosporium-isolated compounds are from marine-derived Chrysosporium. The chemical structures of Chrysosporium-derived compounds have different skeletons, which are concentrated in alkaloids, polyketides, and lactones. Eighty percent of the natural products isolated from Chrysosporium have been found to have various biological activities, including cytotoxic, antibacterial, antifungal and enzyme-inhibitory activities. These results demonstrate the potential of Chrysosporium for producing new bioactive secondary metabolites, which can be used as the structural basis for developing new drugs. Full article

(This article belongs to the Special Issue New Research on Fungal Secondary Metabolites)

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8 pages, 251 KiB

Open AccessArticle

Optimization of Solid-State Fermentation Conditions of Quercus liaotungensis by Bacillus subtilis

by Cong Li, Longteng Ma, Lifen Wang, Zixi Zhang, Yuguang Chen, Jiashun Chen, Qian Jiang, Zehe Song, Xi He, Bie Tan, Dingfu Xiao and Xiaokang Ma

Fermentation 2023, 9(1), 75; https://doi.org/10.3390/fermentation9010075 - 16 Jan 2023

Cited by 5 | Viewed by 2306

Abstract

The current study aimed to investigate the solid-state fermentation process of Quercus liaotungensis (QL) by Bacillus subtilis (BS). The parameters included the inoculation amount, the soybean meal addition amount, the fermentation temperature and the ratio of material to water. The optimal process was [...] Read more.

The current study aimed to investigate the solid-state fermentation process of Quercus liaotungensis (QL) by Bacillus subtilis (BS). The parameters included the inoculation amount, the soybean meal addition amount, the fermentation temperature and the ratio of material to water. The optimal process was determined based on the nutritional value, tannin content and DPPH clearance of QL after fermentation. The results showed that: (1) The parameters of the optimal process included inoculating 10⁶ BS per gram of QL, then adding 10% soybean meal, the ratio of material to the water of 100:80, and temperature at 33 °C for 72 h. (2) In the optimum fermentation conditions, the crude fiber content, and the ether extract content of QL decreased by 66.94% and 66.96%, respectively (p < 0.05). Moreover, the crude protein content and the ash content increased by 65.81% and 4.63%, respectively, after fermentation (p < 0.05). Additionally, the tannin content decreased by 62.77% (p < 0.05), and the DPPH scavenging rate decreased by 45.45% (p < 0.05) after fermentation, respectively. In summary, the QL significantly improved the nutritional value after the solid-state fermentation with BS. Full article

(This article belongs to the Special Issue Bioactive Compounds in Grain Fermentation)

18 pages, 2764 KiB

Open AccessArticle

Dynamic Interplay between O₂ Availability, Growth Rates, and the Transcriptome of Yarrowia lipolytica

by Abraham A. J. Kerssemakers, Süleyman Øzmerih, Gürkan Sin and Suresh Sudarsan

Fermentation 2023, 9(1), 74; https://doi.org/10.3390/fermentation9010074 - 16 Jan 2023

Viewed by 3121

Abstract

Industrial-sized fermenters differ from the laboratory environment in which bioprocess development initially took place. One of the issues that can lead to reduced productivity on a large scale or even early termination of the process is the presence of bioreactor heterogeneities. This work [...] Read more.

Industrial-sized fermenters differ from the laboratory environment in which bioprocess development initially took place. One of the issues that can lead to reduced productivity on a large scale or even early termination of the process is the presence of bioreactor heterogeneities. This work proposes and adopts a design–build–test–learn-type workflow that estimates the substrate, oxygen, and resulting growth heterogeneities through a compartmental modelling approach and maps Yarrowia lipolytica-specific behavior in this relevant range of conditions. The results indicate that at a growth rate of 0.1 h⁻¹, the largest simulated volume (90 m³) reached partial oxygen limitation. Throughout the fed-batch, the cells experienced dissolved oxygen values from 0 to 75% and grew at rates of 0 to 0.2 h⁻¹. These simulated large-scale conditions were tested in small-scale cultivations, which elucidated a transcriptome with a strong downregulation of various transporter and central carbon metabolism genes during oxygen limitation. The relation between oxygen availability and differential gene expression was dynamic and did not show a simple on–off behavior. This indicates that Y. lipolytica can differentiate between different available oxygen concentrations and adjust its transcription accordingly. The workflow presented can be used for Y. lipolytica-based strain engineering, thereby accelerating bioprocess development. Full article

(This article belongs to the Special Issue Yarrowia lipolytica: A Beneficial Yeast as a Biofactory for Biotechnological Applications)

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21 pages, 8937 KiB

Open AccessReview

Moving towards the Application of Biocatalysis in Food Waste Biorefinery

by Sanjib Kumar Karmee

Fermentation 2023, 9(1), 73; https://doi.org/10.3390/fermentation9010073 - 16 Jan 2023

Cited by 8 | Viewed by 3675

Abstract

Waste valorization is an important strategy to reduce environmental pollution and dependency on petroleum-based fuels. In this regard, utilization of food waste as a versatile and low-cost resource is important. Several advanced catalytic methods for the valorization of food waste have been widely [...] Read more.

Waste valorization is an important strategy to reduce environmental pollution and dependency on petroleum-based fuels. In this regard, utilization of food waste as a versatile and low-cost resource is important. Several advanced catalytic methods for the valorization of food waste have been widely investigated for the production of liquid biofuels. Along this line, chemical catalysts have been explored for the synthesis of liquid biofuels. Chemo-catalysis is mainly metal based, which requires harsh process conditions. Alternatively, biocatalysts are currently being investigated as a result of several advantages such as mild reaction conditions, recyclability, selectivity and biodegradability. In this work, recent biocatalytic technologies for the preparation of liquid biofuels through food waste valorization are discussed thoroughly. Lipases are employed for the synthesis of biodiesel and the upgradation of bio-oil, whereas methane mono-oxygenases could be explored for the production of methanol via the oxidation of methane generated from food wastes. Industrial production of ethanol from food waste using bioconversion technologies is a success story. To date, there has been no specific report on the use of food waste for propanol preparation using enzymes. The ABE process (Acetone–Butanol–Ethanol) (using suitable microorganisms) is used for butanol preparation, where the vacuum stripping system is integrated to remove butanol from the broth and circumvent inhibition. The synthesis of hydrocarbon fuels from fatty acids and triglycerides can be carried out using enzymes, such as carboxylic acid reductase and fatty acid photodecarboxylase (an algal photoenzyme). Both carboxylic acid reductase and fatty acid photodecarboxylase have not yet been applied in the direct valorization of food wastes. Furthermore, limitations of the reported methods, societal and economic aspects and a fresh perspective on the subject, along with important examples, are described. Full article

(This article belongs to the Collection Food Waste Valorization)

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20 pages, 1716 KiB

Open AccessArticle

Physiological and Molecular Characterization of Yeast Cultures Pre-Adapted for Fermentation of Lignocellulosic Hydrolysate

by João R. M. Almeida, Magnus Wiman, Dominik Heer, Daniel P. Brink, Uwe Sauer, Bärbel Hahn-Hägerdal, Gunnar Lidén and Marie F. Gorwa-Grauslund

Fermentation 2023, 9(1), 72; https://doi.org/10.3390/fermentation9010072 - 14 Jan 2023

Cited by 4 | Viewed by 2319

Abstract

Economically feasible bioethanol process from lignocellulose requires efficient fermentation by yeast of all sugars present in the hydrolysate. However, when exposed to lignocellulosic hydrolysate, Saccharomyces cerevisiae is challenged with a variety of inhibitors that reduce yeast viability, growth, and fermentation rate, and in [...] Read more.

Economically feasible bioethanol process from lignocellulose requires efficient fermentation by yeast of all sugars present in the hydrolysate. However, when exposed to lignocellulosic hydrolysate, Saccharomyces cerevisiae is challenged with a variety of inhibitors that reduce yeast viability, growth, and fermentation rate, and in addition damage cellular structures. In order to evaluate the capability of S. cerevisiae to adapt and respond to lignocellulosic hydrolysates, the physiological effect of cultivating yeast in the spruce hydrolysate was comprehensively studied by assessment of yeast performance in simultaneous saccharification and fermentation (SSF), measurement of furaldehyde reduction activity, assessment of conversion of phenolic compounds and genome-wide transcription analysis. The yeast cultivated in spruce hydrolysate developed a rapid adaptive response to lignocellulosic hydrolysate, which significantly improved its fermentation performance in subsequent SSF experiments. The adaptation was shown to involve the induction of NADPH-dependent aldehyde reductases and conversion of phenolic compounds during the fed-batch cultivation. These properties were correlated to the expression of several genes encoding oxidoreductases, notably AAD4, ADH6, OYE2/3, and YML131w. The other most significant transcriptional changes involved genes involved in transport mechanisms, such as YHK8, FLR1, or ATR1. A large set of genes were found to be associated with transcription factors (TFs) involved in stress response (Msn2p, Msn4p, Yap1p) but also cell growth and division (Gcr4p, Ste12p, Sok2p), and these TFs were most likely controlling the response at the post-transcriptional level. Full article

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

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17 pages, 553 KiB

Open AccessReview

Recent Advances on the Production of Itaconic Acid via the Fermentation and Metabolic Engineering

by Renwei Zhang, Huan Liu, Yuchen Ning, Yue Yu, Li Deng and Fang Wang

Fermentation 2023, 9(1), 71; https://doi.org/10.3390/fermentation9010071 - 14 Jan 2023

Cited by 15 | Viewed by 3700

Abstract

Itaconic acid (ITA) is one of the top 12 platform chemicals. The global ITA market is expanding due to the rising demand for bio-based unsaturated polyester resin and its non-toxic qualities. Although bioconversion using microbes is the main approach in the current industrial [...] Read more.

Itaconic acid (ITA) is one of the top 12 platform chemicals. The global ITA market is expanding due to the rising demand for bio-based unsaturated polyester resin and its non-toxic qualities. Although bioconversion using microbes is the main approach in the current industrial production of ITA, ecological production of bio-based ITA faces several issues due to: low production efficiency, the difficulty to employ inexpensive raw materials, and high manufacturing costs. As metabolic engineering advances, the engineering of microorganisms offers a novel strategy for the promotion of ITA bio-production. In this review, the most recent developments in the production of ITA through fermentation and metabolic engineering are compiled from a variety of perspectives, including the identification of the ITA synthesis pathway, the metabolic engineering of natural ITA producers, the design and construction of the ITA synthesis pathway in model chassis, and the creation, as well as application, of new metabolic engineering strategies in ITA production. The challenges encountered in the bio-production of ITA in microbial cell factories are discussed, and some suggestions for future study are also proposed, which it is hoped offers insightful views to promote the cost-efficient and sustainable industrial production of ITA. Full article

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

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19 pages, 6015 KiB

Open AccessArticle

A Method for Improving Microbial Conversion of Diosgenin and Separation and Identification of the Product

by Fangyuan Mou, Junmian Tian, Yulu Li, Shiyao Han, Ruifen Shang, Yuxin Song, Shirong Feng, Yongli Zhang, Rang Cao and Baofu Qin

Fermentation 2023, 9(1), 70; https://doi.org/10.3390/fermentation9010070 - 13 Jan 2023

Cited by 1 | Viewed by 2480

Abstract

Diosgenin, a hydrolysis product from Dioscorea plants, can be used as a precursor of steroid drugs (e.g., progesterone, testosterone, and glucocorticoid). However, traditional acid hydrolysis production wastes water and causes severe environmental pollution. The extraction of diosgenin through microbial transformation is the most [...] Read more.

Diosgenin, a hydrolysis product from Dioscorea plants, can be used as a precursor of steroid drugs (e.g., progesterone, testosterone, and glucocorticoid). However, traditional acid hydrolysis production wastes water and causes severe environmental pollution. The extraction of diosgenin through microbial transformation is the most green and environmentally friendly method at present. In order to improve the efficiency of the extraction of diosgenin through microbial transformation, we proposed a new method of strain mutagenesis. After mutagenesis, the response surface methodology was used to optimize the solid-state fermentation medium, thereby improving the diosgenin yield. We found that the optimal formulation was 5.5% sucrose, 0.6% NH₄H₂PO₄, and 26.6% wheat bran. The final extraction rate of diosgenin reached 0.439% (the value of diosgenin per g. of starting plant dry material). Compared with 0.338% before optimization, it had increased 1.29 times. Furthermore, two other compounds were isolated from the fermentation products. These were identified as diosgenone (C₂₇H₄₁O₃) and yuccagenone (C₂₇H₄₂O₃). Traditional diosgenone is obtained through the oxidation of diosgenin with oxalic acid, but the method in this study is directly obtained from Dioscorea rhizome powder. The price of Dioscorea rhizome powder is much lower than diosgenin, thus greatly reducing the cost of obtaining diosgenone. This method provides a basis for subsequent research on other pharmacological compounds. Full article

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

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17 pages, 2794 KiB

Open AccessArticle

Thermodynamic Equilibrium Study of Anaerobic Digestion through Helmholtz Equation of State

by Fabio Giudici, Federico Moretta and Giulia Bozzano

Fermentation 2023, 9(1), 69; https://doi.org/10.3390/fermentation9010069 - 13 Jan 2023

Cited by 1 | Viewed by 2352

Abstract

The growing attention regarding a more sustainable future, and thus into energy recovery and waste reduction technologies, has intensified the interest towards processes which allow to exploit waste and biomasses to generate energy, such as the anaerobic digestion. Improving the efficiency of this [...] Read more.

The growing attention regarding a more sustainable future, and thus into energy recovery and waste reduction technologies, has intensified the interest towards processes which allow to exploit waste and biomasses to generate energy, such as the anaerobic digestion. Improving the efficiency of this industrial application is crucial to increase methane production, and is essential from the economic, environmental and safety point of view. This study focuses on the thermodynamic modelling of a steady-state reactor as a flash unit, in order to determine the best operating conditions to produce the maximum amount of pure bio-methane. To this purpose, a new hybrid approach based on the Peng–Robinson cubic equation of state and on the Multi-Parameter Helmholtz-Energy EoS has been proposed. The simulations, performed using the developed algorithm at temperatures between 20 and 55 °C and at pressure values between 0.3 atm and 1.5 atm, point out that the fugacity of the mixture evaluated with the proposed technique is much more accurate and reliable than the one calculated with the PR EoS. In addition, this research has shown not only that the purity and the production of the biogas can be optimised by working at mesophilic conditions and at pressure between 1 atm and 1.5 atm, but also that it is not convenient to operate in a temperature range of 42 °C–45 °C, since about 20 % more

H_{2} S

goes into the exiting biogas, reducing the

C H_{4}

amount and raising the post-treatment costs. Lastly, it has been seen that there is a significant water content in the vapour phase (∼5 %wt.), and this is a factor to be taken into account in order to improve the process. Full article

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

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19 pages, 2840 KiB

Open AccessArticle

The Impact of Wet Fermentation on Coffee Quality Traits and Volatile Compounds Using Digital Technologies

by Hanjing Wu, Claudia Gonzalez Viejo, Sigfredo Fuentes, Frank R. Dunshea and Hafiz A. R. Suleria

Fermentation 2023, 9(1), 68; https://doi.org/10.3390/fermentation9010068 - 13 Jan 2023

Cited by 10 | Viewed by 4560

Abstract

Fermentation is critical for developing coffee’s physicochemical properties. This study aimed to assess the differences in quality traits between fermented and unfermented coffee with four grinding sizes of coffee powder using multiple digital technologies. A total of N = 2 coffee treatments—(i) dry [...] Read more.

Fermentation is critical for developing coffee’s physicochemical properties. This study aimed to assess the differences in quality traits between fermented and unfermented coffee with four grinding sizes of coffee powder using multiple digital technologies. A total of N = 2 coffee treatments—(i) dry processing and (ii) wet fermentation—with grinding levels (250, 350, 550, and 750 µm) were analysed using near-infrared spectrometry (NIR), electronic nose (e-nose), and headspace/gas chromatography–mass spectrometry (HS-SPME-GC-MS) coupled with machine learning (ML) modelling. Most overtones detected by NIR were within the ranges of 1700–2000 nm and 2200–2396 nm, while the enhanced peak responses of fermented coffee were lower. The overall voltage of nine e-nose sensors obtained from fermented coffee (250 µm) was significantly higher. There were two ML classification models to classify processing and brewing methods using NIR (Model 1) and e-nose (Model 2) values as inputs that were highly accurate (93.9% and 91.2%, respectively). Highly precise ML regression Model 3 and Model 4 based on the same inputs for NIR (R = 0.96) and e-nose (R = 0.99) were developed, respectively, to assess 14 volatile aromatic compounds obtained by GC-MS. Fermented coffee showed higher 2-methylpyrazine (2.20 ng/mL) and furfuryl acetate (2.36 ng/mL) content, which induces a stronger fruity aroma. This proposed rapid, reliable, and low-cost method was shown to be effective in distinguishing coffee postharvest processing methods and evaluating their volatile compounds, which has the potential to be applied for coffee differentiation and quality assurance and control. Full article

(This article belongs to the Special Issue Smart Production and Assessment of Fermented Foods and Beverages Using Digital Technologies)

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12 pages, 1844 KiB

Open AccessArticle

Degradation Kinetics of Lignocellulolytic Enzymes in a Biogas Reactor Using Quantitative Mass Spectrometry

by Jan Küchler, Katharina Willenbücher, Elisabeth Reiß, Lea Nuß, Marius Conrady, Patrice Ramm, Ulrike Schimpf, Udo Reichl, Ulrich Szewzyk and Dirk Benndorf

Fermentation 2023, 9(1), 67; https://doi.org/10.3390/fermentation9010067 - 12 Jan 2023

Cited by 2 | Viewed by 2072

Abstract

The supplementation of lignocellulose-degrading enzymes can be used to enhance the performance of biogas production in industrial biogas plants. Since the structural stability of these enzyme preparations is essential for efficient application, reliable methods for the assessment of enzyme stability are crucial. Here, [...] Read more.

The supplementation of lignocellulose-degrading enzymes can be used to enhance the performance of biogas production in industrial biogas plants. Since the structural stability of these enzyme preparations is essential for efficient application, reliable methods for the assessment of enzyme stability are crucial. Here, a mass-spectrometric-based assay was established to monitor the structural stability of enzymes, i.e., the structural integrity of these proteins, in anaerobic digestion (AD). The analysis of extracts of Lentinula edodes revealed the rapid degradation of lignocellulose-degrading enzymes, with an approximate half-life of 1.5 h. The observed low structural stability of lignocellulose-degrading enzymes in AD corresponded with previous results obtained for biogas content. The established workflow can be easily adapted for the monitoring of other enzyme formulations and provides a platform for evaluating the effects of enzyme additions in AD, together with a characterization of the biochemical methane potential used in order to determine the biodegradability of organic substrates. Full article

(This article belongs to the Special Issue Anaerobic Fermentation – a Biological Route towards Achieving Net Neutrality)

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14 pages, 1152 KiB

Open AccessArticle

The Influence of Lactic Acid Bacteria Fermentation on the Bioactivity of Crayfish (Faxonius limosus) Meat

by Natalia Śmietana, Przemysław Śmietana, Emilia Drozłowska and Łukasz Łopusiewicz

Fermentation 2023, 9(1), 66; https://doi.org/10.3390/fermentation9010066 - 12 Jan 2023

Cited by 2 | Viewed by 2931

Abstract

In recent years, new raw materials have been sought for use in processing. This category certainly includes invasive crayfish Faxonius limosus. One of the problems associated with their use is their short microbiological shelf life. Therefore, in the research presented here, an [...] Read more.

In recent years, new raw materials have been sought for use in processing. This category certainly includes invasive crayfish Faxonius limosus. One of the problems associated with their use is their short microbiological shelf life. Therefore, in the research presented here, an attempt was made to ferment crayfish meat with strains of Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, Lactobacillus casei, and yogurt culture. The analyses included an evaluation of changes in the microbial quality of the material, the content of free amino acids, reducing sugars, ascorbic acid, and the antioxidant properties of the fermented meat. Changes in the canthaxanthin content and the number of sulfhydryl groups and disulfide bridges were also evaluated. The study showed that carrying out lactic fermentation resulted in a decrease in meat pH (8.00 to 7.35–6.94, depending on the starter culture). Moreover, the meat was characterized by an increase in FRAP (2.99 to 3.60–4.06 mg AAE/g), ABTS (2.15 to 2.85–3.50 μmol Trolox/g), and reducing power (5.53 to 6.28–14.25 μmol Trolox/g). In addition, the study showed a favorable effect of fermentation on the content of sulfhydryl groups in the meat as well as for ascorbic acid content. The results obtained can serve as a starting point for the further development of fermented products based on crayfish meat. Full article

(This article belongs to the Special Issue Bioactivity Change in Fermented Foods)

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22 pages, 6864 KiB

Open AccessArticle

In Silico Prediction of Secondary Metabolites and Biosynthetic Gene Clusters Analysis of Streptomyces thinghirensis HM3 Isolated from Arid Soil

by Medhat Rehan, Abdellatif Gueddou, Abdulaziz Alharbi and Imen Ben Abdelmalek

Fermentation 2023, 9(1), 65; https://doi.org/10.3390/fermentation9010065 - 12 Jan 2023

Cited by 4 | Viewed by 3948

Abstract

Natural products produced by microorganisms are considered an important resource of bioactive secondary metabolites, such as anticancer, antifungal, antibiotic, and immunosuppressive molecules. Streptomyces are the richest source of bioactive natural products via possessing a wide number of secondary metabolite biosynthetic gene clusters (SM-BGCs). [...] Read more.

Natural products produced by microorganisms are considered an important resource of bioactive secondary metabolites, such as anticancer, antifungal, antibiotic, and immunosuppressive molecules. Streptomyces are the richest source of bioactive natural products via possessing a wide number of secondary metabolite biosynthetic gene clusters (SM-BGCs). Based on rapid development in sequencing technologies with advances in genome mining, exploring the newly isolated Streptomyces species for possible new secondary metabolites is mandatory to find novel natural products. The isolated Streptomyces thinghirensis strain HM3 from arid and sandy texture soil in Qassim, SA, exerted inhibition activity against tested animal pathogenic Gram-positive bacteria and pathogenic fungal species. In this study, we report the draft genome of S. thinghirensis strain HM3, which consists of 7,139,324 base pairs (bp), with an average G+C content of 71.49%, predicting 7949 open reading frames, 12 rRNA operons (5S, 16S, 23S) and 60 tRNAs. An in silico analysis of strain HM3 genome by the antiSMASH and PRISM 4 online software for SM-BGCs predicted 16 clusters, including four terpene, one lantipeptide, one siderophore, two polyketide synthase (PKS), two non-ribosomal peptide synthetase (NRPS) cluster)/NRPS-like fragment, two RiPP/RiPP-like (ribosomally synthesised and post-translationally modified peptide product), two butyrolactone, one CDPS (tRNA-dependent cyclodipeptide synthases), and one other (cluster containing a secondary metabolite-related protein that does not fit into any other category) BGC. The presented BGCs inside the genome, along with antibacterial and antifungal activity, indicate that HM3 may represent an invaluable source for new secondary metabolites. Full article

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

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14 pages, 2327 KiB

Open AccessArticle

Confirmation of Glucose Transporters through Targeted Mutagenesis and Transcriptional Analysis in Clostridium acetobutylicum

by Kundi Zhang, Dandan Jiang, Wolfgang Liebl, Maofeng Wang, Lichuan Gu, Ziyong Liu and Armin Ehrenreich

Fermentation 2023, 9(1), 64; https://doi.org/10.3390/fermentation9010064 - 12 Jan 2023

Viewed by 2032

Abstract

The solvent-producing bacterium Clostridium acetobutylicum is able to grow on a variety of carbohydrates. The main hexose transport system is the phosphoenolpyruvate-dependent phosphotransferase system (PTS). When the gene glcG that encodes the glucose transporter was inactivated, the resulting mutant glcG::int(1224) grew as [...] Read more.

The solvent-producing bacterium Clostridium acetobutylicum is able to grow on a variety of carbohydrates. The main hexose transport system is the phosphoenolpyruvate-dependent phosphotransferase system (PTS). When the gene glcG that encodes the glucose transporter was inactivated, the resulting mutant glcG::int(1224) grew as well as the wild type, yet its glucose consumption was reduced by 17% in a batch fermentation. Transcriptomics analysis of the phosphate-limited continuous cultures showed that the cellobiose transporter GlcCE was highly up-regulated in the mutant glcG::int(1224). The glcCE mutation did not affect growth and even consumed slightly more glucose during solventogenesis growth compared to wild type, indicating that GlcG is the primary glucose-specific PTS. Poor growth of the double mutant glcG::int(1224)-glcCE::int(193) further revealed that GlcCE was the secondary glucose PTS and that there must be other PTSs capable of glucose uptake. The observations obtained in this study provided a promising foundation to understand glucose transport in C. acetobutylicum. Full article

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

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11 pages, 2821 KiB

Open AccessArticle

Culture Age, Growth Medium, Ultrasound Amplitude, and Time of Exposure Influence the Kinetic Growth of Lactobacillus acidophilus

by Norma Angélica Bolivar-Jacobo, Raúl Alberto Reyes-Villagrana, Ana Luisa Rentería-Monterrubio, Rogelio Sánchez-Vega, Eduardo Santellano-Estrada, Juan Manuel Tirado-Gallegos and América Chávez-Martínez

Fermentation 2023, 9(1), 63; https://doi.org/10.3390/fermentation9010063 - 12 Jan 2023

Cited by 9 | Viewed by 3694

Abstract

The growth pattern of probiotics can be modified by changing their nutritional factors and their physiological stage. Meanwhile, high intensity ultrasound (HIUS) can be employed to increase probiotics’ biomass. The one-factor-at-a-time (OFAT) approach was employed to investigate the influence of the growth medium [...] Read more.

The growth pattern of probiotics can be modified by changing their nutritional factors and their physiological stage. Meanwhile, high intensity ultrasound (HIUS) can be employed to increase probiotics’ biomass. The one-factor-at-a-time (OFAT) approach was employed to investigate the influence of the growth medium (MRS broth, whole milk, and skim milk), culture age (1 day and 7 days old) and ultrasound parameters (time and amplitude) on the kinetic parameters of L. acidophilus. The oldest culture (7 days) had a greater lag phase and time to reach the end of the sigmoidal curve (T_max) (p < 0.05) as well as a lower rate (maximum growth potential μ_max) compared to the youngest culture (1 day). Regarding the growth medium, skim milk presented the greatest L. acidophilus counts (p < 0.05). Meanwhile, sonication times (60 and 90 s) change µ_max and T_max. When 30% amplitude was applied, a greater μ_max and a smaller T_max were observed (p < 0.05). It can be concluded that the growth medium, culture age, and ultrasound parameters (time and amplitude) influence the kinetic parameters of L. acidophilus. Results from this study could be used in the design and optimization of processes to improve the growth of the probiotic L. acidophilus at industrial scale. Full article

(This article belongs to the Special Issue Dairy Fermentation)

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26 pages, 2044 KiB

Open AccessReview

A Review of Basic Bioinformatic Techniques for Microbial Community Analysis in an Anaerobic Digester

by Apoorva Upadhyay, Andrey A. Kovalev, Elena A. Zhuravleva, Dmitriy A. Kovalev, Yuriy V. Litti, Shyam Kumar Masakapalli, Nidhi Pareek and Vivekanand Vivekanand

Fermentation 2023, 9(1), 62; https://doi.org/10.3390/fermentation9010062 - 12 Jan 2023

Cited by 6 | Viewed by 4645

Abstract

Biogas production involves various types of intricate microbial populations in an anaerobic digester (AD). To understand the anaerobic digestion system better, a broad-based study must be conducted on the microbial population. Deep understanding of the complete metagenomics including microbial structure, functional gene form, [...] Read more.

Biogas production involves various types of intricate microbial populations in an anaerobic digester (AD). To understand the anaerobic digestion system better, a broad-based study must be conducted on the microbial population. Deep understanding of the complete metagenomics including microbial structure, functional gene form, similarity/differences, and relationships between metabolic pathways and product formation, could aid in optimization and enhancement of AD processes. With advancements in technologies for metagenomic sequencing, for example, next generation sequencing and high-throughput sequencing, have revolutionized the study of microbial dynamics in anaerobic digestion. This review includes a brief introduction to the basic process of metagenomics research and includes a detailed summary of the various bioinformatics approaches, viz., total investigation of data obtained from microbial communities using bioinformatics methods to expose metagenomics characterization. This includes (1) methods of DNA isolation and sequencing, (2) investigation of anaerobic microbial communities using bioinformatics techniques, (3) application of the analysis of anaerobic microbial community and biogas production, and (4) restriction and prediction of bioinformatics analysis on microbial metagenomics. The review has been concluded, giving a summarized insight into bioinformatic tools and also promoting the future prospects of integrating humungous data with artificial intelligence and neural network software. Full article

(This article belongs to the Section Industrial Fermentation)

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12 pages, 2897 KiB

Open AccessArticle

Efficient Co-Production of Xylooligosaccharides and Glucose from Vinegar Residue by Biphasic Phenoxyethanol-Maleic Acid Pretreatment

by Yuanyuan Zhu, Ruijun Tang, Yongjian Yu, Zhen Yu, Ke Wang, Yuqin Wang, Peng Liu and Dong Han

Fermentation 2023, 9(1), 61; https://doi.org/10.3390/fermentation9010061 - 11 Jan 2023

Cited by 14 | Viewed by 2096

Abstract

A new biphasic organic solvent, phenoxyethanol-maleic acid, was carried out to pretreat and fractionate vinegar residue into glucan, xylan and lignin under mild conditions. Additional effects of key factors, temperature and phenoxyethanol concentration, on vinegar residue, were evaluated. Under the biphasic system (0.5% [...] Read more.

A new biphasic organic solvent, phenoxyethanol-maleic acid, was carried out to pretreat and fractionate vinegar residue into glucan, xylan and lignin under mild conditions. Additional effects of key factors, temperature and phenoxyethanol concentration, on vinegar residue, were evaluated. Under the biphasic system (0.5% maleic acid, 60% phenoxyethanol), 140 °C cooking vinegar residue for 1 h, 80.91% of cellulose retention in solid residue, 75.44% of hemicellulose removal and 69.28% of lignin removal were obtained. Optimal identified conditions resulted in maximum XOS of 47.3%. Then, the solid residue was enzymatically digested with a glucose yield of 82.67% at 72 h with the addition of 2.5 g/L bovine serum albumin. Finally, the residue was characterized by SEM, FTIR, XRD and BET analysis. This work demonstrated the phenoxyethanol-maleic acid pretreatment yielded XOS, fermentable sugar, and lignin with high processibility. Full article

(This article belongs to the Special Issue Lignocellulosic Biomass Decomposition and Bioconversion)

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20 pages, 3070 KiB

Open AccessArticle

Effect of Alkaline and Mechanical Pretreatment of Wheat Straw on Enrichment Cultures from Pachnoda marginata Larva Gut

by Bruna Grosch Schroeder, Havva Betül İstanbullu, Matthias Schmidt, Washington Logroño, Hauke Harms and Marcell Nikolausz

Fermentation 2023, 9(1), 60; https://doi.org/10.3390/fermentation9010060 - 11 Jan 2023

Cited by 5 | Viewed by 2176

Abstract

In order to partially mimic the efficient lignocellulose pretreatment process performed naturally in the gut system of Pachnoda marginata larvae, two wheat straw pretreatments were evaluated: a mechanical pretreatment via cutting the straw into two different sizes and an alkaline pretreatment with calcium [...] Read more.

In order to partially mimic the efficient lignocellulose pretreatment process performed naturally in the gut system of Pachnoda marginata larvae, two wheat straw pretreatments were evaluated: a mechanical pretreatment via cutting the straw into two different sizes and an alkaline pretreatment with calcium hydroxide. After pretreatment, gut enrichment cultures on wheat straw at alkaline pH were inoculated and kept at mesophilic conditions over 45 days. The methanogenic community was composed mainly of the Methanomicrobiaceae and Methanosarcinaceae families. The combined pretreatment, size reduction and alkaline pretreatment, was the best condition for methane production. The positive effect of the straw pretreatment was higher in the midgut cultures, increasing the methane production by 192%, while for hindgut cultures the methane production increased only by 149% when compared to non-pretreated straw. Scanning electron microscopy (SEM) showed that the alkaline pretreatment modified the surface of the wheat straw fibers, which promoted biofilm formation and microbial growth. The enrichment cultures derived from larva gut microbiome were able to degrade larger 1 mm alkaline treated and smaller 250 µm but non-pretreated straw at the same efficiency. The combination of mechanical and alkaline pretreatments resulted in increased, yet not superimposed, methane yield. Full article

(This article belongs to the Special Issue Bioconversion of Lignocellulosic Materials to Value-Added Products 2.0)

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15 pages, 1776 KiB

Open AccessArticle

Evaluation of Laminaria Digitata Hydrolysate for the Production of Bioethanol and Butanol by Fermentation

by Antoine Moenaert, Ana M. López-Contreras, Miriam Budde, Leila Allahgholi, Xiaoru Hou, Anne-Belinda Bjerre, Johann Örlygsson, Eva Nordberg Karlsson, Ólafur H. Friðjónsson and Guðmundur Óli Hreggviðsson

Fermentation 2023, 9(1), 59; https://doi.org/10.3390/fermentation9010059 - 11 Jan 2023

Cited by 6 | Viewed by 2526

Abstract

Seaweeds (macroalgae) are gaining attention as potential sustainable feedstock for the production of fuels and chemicals. This comparative study focuses on the characterization of the microbial production of alcohols from fermentable carbohydrates in the hydrolysate of the macroalgae Laminaria digitata as raw material. [...] Read more.

Seaweeds (macroalgae) are gaining attention as potential sustainable feedstock for the production of fuels and chemicals. This comparative study focuses on the characterization of the microbial production of alcohols from fermentable carbohydrates in the hydrolysate of the macroalgae Laminaria digitata as raw material. The potential of a hydrolysate as a carbon source for the production of selected alcohols was tested, using three physiologically different fermentative microbes, in two main types of processes. For the production of ethanol, Saccharomyces cerevisiae was used as a benchmark microorganism and compared with the strictly anaerobic thermophile Thermoanaerobacterium strain AK17. For mixed production of acetone/isopropanol, butanol, and ethanol (A/IBE), three strictly anaerobic Clostridium strains were compared. All strains grew well on the hydrolysate, and toxicity constraints were not observed, but fermentation performance and product profiles were shown to be both condition- and strain-specific. S. cerevisiae utilized only glucose for ethanol formation, while strain AK17 utilized glucose, mannitol, and parts of the glucan oligosaccharides. The clostridia strains tested showed different nutrient requirements, and were able to utilize glucan, mannitol, and organic acids in the hydrolysate. The novelty of this study embodies the application of different inoculates for fermenting a common brown seaweed found in the northern Atlantic Ocean. It provides important information on the fermentation properties of different microorganisms and pinpoints the value of carbon source utilization when selecting microbes for efficient bioconversion into biofuel and chemical products of interest. Full article

(This article belongs to the Special Issue Biofuels Production and Processing Technology 2.0)

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18 pages, 345 KiB

Open AccessArticle

Nutritional and Phytochemical Composition of Mahewu (a Southern African Fermented Food Product) Derived from White and Yellow Maize (Zea mays) with Different Inocula

by Grace Abosede Daji, Ezekiel Green and Oluwafemi Ayodeji Adebo

Fermentation 2023, 9(1), 58; https://doi.org/10.3390/fermentation9010058 - 10 Jan 2023

Cited by 9 | Viewed by 4380

Abstract

Mahweu is an important indigenous beverage for many low-income and undernourished consumers in southern Africa. As a result, the nutritional and phytochemical profile of mahewu samples (obtained using optimized fermentation and boiling conditions from a previous study) as well as their related raw [...] Read more.

Mahweu is an important indigenous beverage for many low-income and undernourished consumers in southern Africa. As a result, the nutritional and phytochemical profile of mahewu samples (obtained using optimized fermentation and boiling conditions from a previous study) as well as their related raw materials (white and yellow maize) were investigated. At these conditions, white and yellow maize mahewu (WM and YM) were prepared utilizing various inocula including sorghum malt, wheat, millet malt, or maize malt, and the pH, titratable acidity (TTA), total soluble solid (TSS), and proximate analysis were determined. The mineral content, amino acid composition, and phenolic compound profile were also investigated using inductive coupled plasma optical emission spectrometry (ICP-OES), high-performance liquid chromatography (HPLC), and ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS), respectively. Fermentation was observed to have influenced the proximate composition of obtained mahewu samples compared to the raw flour with significant (p ≤ 0.05) improvement in protein from 8.59 to 9.7% (YM) and 8.78 to 9% (WM) as well as carbohydrate from 72.27 to 74.47% (YM) and 71.15 to 72.65% (WM). Sodium, magnesium, phosphorous, potassium, calcium, manganese, iron, copper, and zinc were the minerals detected in the mahewu samples, while potassium was the most abundant mineral, having values ranging from 3051.61 to 3283.38 mg/kg (YM) and 2882.11 to 3129.97 mg/kg (WM). Heavy metals detected in this study were all below the recommended tolerable levels by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Arginine and leucine with values ranging from 0.47 to 0.52 g/100 g (YM) and 0.48 to 0.53 g/100 g (WM) as well as 0.91 to 1.04 g/100 g (YM) and 0.95 to 1.01 g/100 g (WM), respectively, were the most abundant essential amino acids, whereas for non-essential amino acids, glutamic acid, aspartic acid, alanine, and proline were observed to be abundant. Based on the different inocula, the derived mahewu samples prepared using either white or yellow maize have varying nutritional and health beneficial components and the choice of inocula might still be determined by consumer preference. Full article

(This article belongs to the Special Issue New Insights into the Application of Lactic Acid Bacteria Strain in the Fermentation 2.0)

11 pages, 3083 KiB

Open AccessArticle

Amelioration of Biogas Production from Waste-Activated Sludge through Surfactant-Coupled Mechanical Disintegration

by Vijetha Valsa, Geethu Krishnan S, Rashmi Gondi, Preethi Muthu, Kavitha Sankarapandian, Gopalakrishnan Kumar, Poornachandar Gugulothu and Rajesh Banu Jeyakumar

Fermentation 2023, 9(1), 57; https://doi.org/10.3390/fermentation9010057 - 9 Jan 2023

Viewed by 2265

Abstract

The current study intended to improve the disintegration potential of paper mill sludge through alkyl polyglycoside-coupled disperser disintegration. The sludge biomass was fed to the disperser disintegration and a maximum solubilization of 6% was attained at the specific energy input of 4729.24 kJ/kg [...] Read more.

The current study intended to improve the disintegration potential of paper mill sludge through alkyl polyglycoside-coupled disperser disintegration. The sludge biomass was fed to the disperser disintegration and a maximum solubilization of 6% was attained at the specific energy input of 4729.24 kJ/kg TS. Solubilization was further enhanced by coupling the optimum disperser condition with varying dosage of alkyl polyglycoside. The maximum solubilization of 11% and suspended solid (SS) reduction of 8.42% were achieved at the disperser rpm, time, and surfactant dosage of 12,000, 30 min, and 12 μL. The alkyl polyglycoside-coupled disperser disintegration showed a higher biogas production of 125.1 mL/gCOD, compared to the disperser-alone disintegration (70.1 mL/gCOD) and control (36.1 mL/gCOD). Full article

(This article belongs to the Special Issue Advanced Research in Biomass and Waste Valorization)

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12 pages, 2526 KiB

Open AccessArticle

The Effect of the Stirring Speed on the In Vitro Dry Matter Degradability of Feeds

by Sonia Tassone, Chiara Sarnataro, Sara Glorio Patrucco, Sabah Mabrouki and Salvatore Barbera

Fermentation 2023, 9(1), 56; https://doi.org/10.3390/fermentation9010056 - 9 Jan 2023

Cited by 2 | Viewed by 1681

Abstract

In vitro methods have been standardized and tested to correctly simulate the rumen environment and fermentation process. A few studies have verified that the feed degradability achieved as a result of stirring the samples is higher when the samples are incubated under continuous [...] Read more.

In vitro methods have been standardized and tested to correctly simulate the rumen environment and fermentation process. A few studies have verified that the feed degradability achieved as a result of stirring the samples is higher when the samples are incubated under continuous stirring than when they are only stirred twice daily. The objective of this study has been to verify the effect of the speed of stirring on feed degradability during In vitro incubation. For this purpose, the apparent and true dry matter degradability (ADMD and TDMD) of grass hay, pelleted alfalfa, corn silage, barley meal, straw, and a total mixed ration (TMR) were measured after 48 h of incubation in jars under different rotation speeds. The same types of feed were placed in the four jars of each instrument, and the rotation system of the machine was modified to ensure the simultaneous rotation of a pair of original jars (which sometimes stopped and/or rotated slowly and irregularly) together with a pair of modified jars under regular and continuous rotation. A rev counter data logger was mounted onto the jars, and the rotation speeds of the original and modified jars were measured and compared under different conditions (empty jars, jars with liquid, jars with rumen fluid, and sample bags). The modifications to the instruments stabilized the rotation of the jars, thereby making the stirring more regular during incubation. The degradability was partly influenced by the regular stirring, albeit with just one instrument, and for grass hay, barley meal, corn silage, and TMR. In short, it has been found that the regular stirring of sample bags is not essential to obtain reliable degradability measurement during incubation, although it is better to maintain a constant rotation to ensure a regular and standardized In vitro incubation process and therefore to allow reproducibility and comparisons of the results on feed degradability. Full article

(This article belongs to the Special Issue Rumen Fermentation)

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12 pages, 2155 KiB

Open AccessArticle

Synergistic Effect of Surfactant on Disperser Energy and Liquefaction Potential of Macroalgae (Ulva intestinalis) for Biofuel Production

by Rinsha Puthiya Veettil, Rabia, Dinesh Kumar Mathew, Rashmi Gondi, Kavitha Sankarapandian, Meganathan Kannan, Gopalakrishnan Kumar, Siham Y. Al-Qaradawi and Rajesh Banu Jeyakumar

Fermentation 2023, 9(1), 55; https://doi.org/10.3390/fermentation9010055 - 9 Jan 2023

Cited by 5 | Viewed by 2222

Abstract

The objective of this study was to evaluate the effect of surfactant on disperser homogenization pretreatment for macroalgae (Ulva intestinalis) to enhance biogas production. The macroalgae are subjected to surfactant coupled disperser pretreatment, which enhanced the liquefaction and improved the biomethane [...] Read more.

The objective of this study was to evaluate the effect of surfactant on disperser homogenization pretreatment for macroalgae (Ulva intestinalis) to enhance biogas production. The macroalgae are subjected to surfactant coupled disperser pretreatment, which enhanced the liquefaction and improved the biomethane production. The outcome of this study revealed that 10,000 rpm at 20 min with a specific energy input of 1748.352 kJ/ kg total solids (TS) are the optimum conditions for surfactant disperser pretreatment (SDP), which resulted in the liquefaction rate of 20.08% with soluble organics release of 1215 mg/L and showed a better result than disperser pretreatment (DP) with a liquefaction rate of 14%. Biomethane production through the SDP method was found to be 0.2 g chemical oxygen demand (COD)/g COD, which was higher than DP (0.11 g COD/g COD). SDP was identified to be a synergetic pretreatment method with an energy ratio and net profit of about 0.91 and 104.04 United States dollars (USD)/ton, respectively. Full article

(This article belongs to the Special Issue Algae—the Medium of Bioenergy Conversion)

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12 pages, 5325 KiB

Open AccessArticle

Synthesis of Tungsten Oxide Nanoflakes and Their Antibacterial and Photocatalytic Properties

by Sarinthip Thanakkasaranee, Gopinath Kasi, Sivasamy Kadhiravan, Ayyakannu Arumugam, Khalid A. Al-Ghanim, Mian Nadeem Riaz and Marimuthu Govindarajan

Fermentation 2023, 9(1), 54; https://doi.org/10.3390/fermentation9010054 - 9 Jan 2023

Cited by 4 | Viewed by 3165

Abstract

This current work revealed a single-step fabrication of tungsten oxide nanoflakes (WO₃ NFs) with the help of Terminalia arjuna bark extract. Bioactive phytoconstituents of T. arjuna bark extract were involved in the nucleation process and promoted the material crystalline growth in a [...] Read more.

This current work revealed a single-step fabrication of tungsten oxide nanoflakes (WO₃ NFs) with the help of Terminalia arjuna bark extract. Bioactive phytoconstituents of T. arjuna bark extract were involved in the nucleation process and promoted the material crystalline growth in a particular direction. The as-prepared sample thermal decomposition was analyzed by TG/DTG. The as-prepared sample was annealed at 300 °C for 2 h, and the annealed sample was characterized by UV-Vis-DRS, FTIR, Raman, XRD, SEM, EDX, and TEM. Synthesized WO₃ samples showed a monoclinic phase of the flake-like structure with lengths of 25~230 nm and diameters of 25~120 nm. The WO₃ NFs were evaluated against S. aureus and E. coli. Over 3 mg concentrations of WO₃ NFs outperform the positive control in antibacterial activity. The pseudo-first-order kinetics of the WO₃ NFs enhanced the photocatalytic performance of methylene blue (MB). These results prove that WO₃ NFs have sustainable performance in antibacterial and MB degradation applications. Full article

(This article belongs to the Special Issue Biofilms from Fermentative Perspective: Structures, Functions and Control)

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16 pages, 1996 KiB

Open AccessArticle

Deciphering Microbial Diversity and Functional Codes of Traditional Fermented Whole Grain Tianpei from Typical Regions of China

by Fei Ren, Ming Liu, Yanxiang Liu, Xiaohong Tian, Ping Jiang and Bin Tan

Fermentation 2023, 9(1), 53; https://doi.org/10.3390/fermentation9010053 - 9 Jan 2023

Cited by 1 | Viewed by 2121

Abstract

Whole grains are a crucial part of healthy and sustainable diets, attracting great attention. Tianpei is a popular traditional fermented whole grain food and beverage from China. It is suitable for all ages with lots of health benefits. However, its microflora and their [...] Read more.

Whole grains are a crucial part of healthy and sustainable diets, attracting great attention. Tianpei is a popular traditional fermented whole grain food and beverage from China. It is suitable for all ages with lots of health benefits. However, its microflora and their functions, relations between microbial taxa and functions with Tianpei properties, were still little informed, limiting the fermentation optimization and quality improvement. In this study, the characteristics and distribution of the microbial flora taxa and their functions of the fermented whole grain Tianpei from typical regions of China were mainly deciphered through metagenomic methods. Phyla Mucoromycota, Firmicutes, Ascomycota, and Proteobacteria were the most abundant. Rhizopus, Limosilactobacillus, and Lactobacillus were the most abundant genera. Microbial COG functions carbohydrate transport and metabolism (mainly including fructose, galactose, glucose, L-arabinose, and mannose) and amino acid transport and metabolism (mainly including arginine, asparagine, glutamine, and glycine) kept a high abundance. PCA (Principal Component Analysis) illustrated that the microbial community and their functions of every Tianpei sample clustered individually based on the analysis, related with the factors of raw material and sources. The microbial taxa, microbial functions, and the Tianpei properties were significantly correlated. Rhizopus, Limosilactobacillus, and Lactobacillus contributed most COG functions in Tianpei samples. Analysis of quorum sensing, pfam, secretion protein, probio, and cytochromes P450 were also annotated and found among Tianpei microbial communities. A sum of 105 probiotics were classified, mainly belonging to Lactobacillus, Leuconostoc, Acetobacter, Bacillus, Bifidobacterium, Pediococcus, etc. Tianpei samples made in the library with the most abundant and functional microbial key taxa strains—Rhizophus oryzae, Lactobacillus plantarum, and Limosilactobacillus fermentum—showed rich nutrient chemicals. The results indicate that microbial taxa and their functions could determine Tianpei properties. Thus, the quality, nutrients, flavor, and industrial production of Tianpei could be further investigated, promoted, and improved in the future based on the characteristics of these microbial taxa and their functions, such as the regulations of the main carbohydrate and AA. The study will also lay a foundation for the fermentative characteristics and condition technology of fermented whole grain food. Full article

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

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10 pages, 1883 KiB

Open AccessArticle

Cell Wall Glycan Changes in Different Brachypodium Tissues Give Insights into Monocot Biomass

by Utku Avci

Fermentation 2023, 9(1), 52; https://doi.org/10.3390/fermentation9010052 - 8 Jan 2023

Cited by 1 | Viewed by 2526

Abstract

The annual temperate grass Brachypodium distachyon has become a model system for monocot biomass crops and for understanding lignocellulosic recalcitrance to employ better saccharification and fermentation approaches. It is a monocot plant used to study the grass cell walls that differ from the [...] Read more.

The annual temperate grass Brachypodium distachyon has become a model system for monocot biomass crops and for understanding lignocellulosic recalcitrance to employ better saccharification and fermentation approaches. It is a monocot plant used to study the grass cell walls that differ from the cell walls of dicot plants such as the eudicot model Arabidopsis. The B. distachyon cell wall is predominantly composed of cellulose, arabinoxylans, and mixed-linkage glucans, and it resembles the cell walls of other field grasses. It has a vascular bundle anatomy similar to C3 grasses. These features make Brachypodium an ideal model to study cell walls. Cell walls are composed of polymers with complex structures that vary between cell types and at different developmental stages. Antibodies that recognize specific cell wall components are currently one of the most effective and specific molecular probes to determine the location and distribution of polymers in plant cell walls in situ. Here, we investigated the glycan distribution in the cell walls of the root and leaf tissues of Brachypodium by employing cell-wall-directed antibodies against diverse glycan epitopes. There are distinct differences in the presence of the epitopes between the root and leaf tissues as well as in the cell type level, which gives insights into monocot biomass. Full article

(This article belongs to the Special Issue Cellulose Valorization in Biorefinery)

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18 pages, 4530 KiB

Open AccessEditor’s ChoiceArticle

Selection of Yarrowia lipolytica Strains as Possible Solution to Valorize Untreated Cheese Whey

by Davide Gottardi, Lorenzo Siroli, Giacomo Braschi, Samantha Rossi, Narinder Bains, Lucia Vannini, Francesca Patrignani and Rosalba Lanciotti

Fermentation 2023, 9(1), 51; https://doi.org/10.3390/fermentation9010051 - 7 Jan 2023

Cited by 5 | Viewed by 2845

Abstract

Cheese whey management and disposal is a major issue for dairy industries due to its high level of chemical and biochemical oxygen demand. However, it can still represent a source of nutrients (i.e., sugars, proteins and lipids) that can be applied, among other [...] Read more.

Cheese whey management and disposal is a major issue for dairy industries due to its high level of chemical and biochemical oxygen demand. However, it can still represent a source of nutrients (i.e., sugars, proteins and lipids) that can be applied, among other options, as substrate for microbial growth. Yarrowia lipolytica can grow in different environments, consuming both hydrophilic and hydrophobic substrates, and tolerates high salt concentrations. In this work, the lipolytic and proteolytic profile of 20 strains of Y. lipolytica were tested on caseins and butter. Then, their growth potential was evaluated in four types of whey (caciotta, ricotta, squacquerone and their mix). Y. lipolytica showed a very strain-dependent behavior for both hydrolytic profiles and growth capabilities on the different substrates. The best growers for all the types of whey tested were PO1, PO2, and RO2, with the first one reaching up to 8.77 log cfu/mL in caciotta whey after 72 h. The volatile molecule profile of the samples incubated with the best growers were characterized by higher amounts of esters, acids, ketones and alcohols. In this way, cheese whey can become a source of microbial cultures exploitable in the dairy sector. Full article

(This article belongs to the Special Issue Yarrowia lipolytica: A Beneficial Yeast as a Biofactory for Biotechnological Applications)

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12 pages, 1628 KiB

Open AccessArticle

Effect of Aspergillus niger Fermentation on the Metabolites in Corn Stalks

by Zhen Fan, Tianming Chen, Guolin Cai, Xiaoyu Huang, Suchuan Zhong, Xiaoming Li and Enping Zhang

Fermentation 2023, 9(1), 50; https://doi.org/10.3390/fermentation9010050 - 7 Jan 2023

Cited by 6 | Viewed by 2745

Abstract

Fermentation has been considered as an effective means to improve the feed nutrient digestibility of corn stalks, and it is beneficial to animal growth performance and health. The beneficial functions of fermented corn stalks are related to the variety of metabolites produced through [...] Read more.

Fermentation has been considered as an effective means to improve the feed nutrient digestibility of corn stalks, and it is beneficial to animal growth performance and health. The beneficial functions of fermented corn stalks are related to the variety of metabolites produced through fermentation, but the nature of these components is still unclear. In this study, gas chromatography–mass spectrometry, combined with principal component analysis and partial least squares discriminant analysis, was used to explore the differential metabolites of corn stalks before and after Aspergillus niger fermentation. A total of 32 potential characteristic compounds were obtained, mainly including sugar and glycoside derivatives, organic acids and their derivatives, alcohol compounds, benzene and its substituted derivatives, amino acids, phenolic compounds, and flavonoids. Compared with the metabolites in corn straw before fermentation, the relative content of D-threitol, mannitol-1-phosphate, coniferin, citrazinic, oxoglutaric acid, chenodeoxycholic acid, naproxen, 5-aminovaleric acid, vanillin, catechin, and UDP-glucuronic acid was significantly increased, and the relative content of N-acetylgalactosamine, heneicosanoic acid, chlorogenic acid, and adenosine was significantly decreased. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that 20 metabolic pathways corresponded to the differential characteristic metabolites. The results of this study will provide theoretical support for the quality evaluation of fermented corn stalks and high-value product development in the future. Full article

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

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12 pages, 3167 KiB

Open AccessArticle

Insight into the Substrate Specificity of Lactobacillus paracasei Aspartate Ammonia-Lyase

by Yi-Hao Huang, Weir-Chiang You, Yung-Ju Chen, Jhih-Ying Ciou and Lu-Sheng Hsieh

Fermentation 2023, 9(1), 49; https://doi.org/10.3390/fermentation9010049 - 6 Jan 2023

Cited by 6 | Viewed by 2298

Abstract

Aspartate ammonia-lyase (AAL) catalyzes the reversible conversion reactions of aspartate to fumaric acid and ammonia. In this work, Lactobacillus paracasei LpAAL gene was heterologously expressed in Escherichia coli. As well as a recombinant His-tagged LpAAL protein, a maltose-binding protein (MBP) fused LpAAL protein [...] Read more.

Aspartate ammonia-lyase (AAL) catalyzes the reversible conversion reactions of aspartate to fumaric acid and ammonia. In this work, Lactobacillus paracasei LpAAL gene was heterologously expressed in Escherichia coli. As well as a recombinant His-tagged LpAAL protein, a maltose-binding protein (MBP) fused LpAAL protein was used to enhance its protein solubility and expression level. Both recombinant proteins showed broad substrate specificity, catalyzing aspartic acid, fumaric acid, phenylalanine, and tyrosine to produce fumaric acid, aspartic acid, trans-cinnamic acid, and p-coumaric acid, respectively. The optimum reaction pH and temperature of LpAAL protein for four substrates were measured at 8.0 and 40 °C, respectively. The K_m values of LpAAL protein for aspartic acid, fumaric acid, phenylalanine, and tyrosine as substrates were 5.7, 8.5, 4.4, and 1.2 mM, respectively. The k_cat values of LpAAL protein for aspartic acid, fumaric acid, phenylalanine, and tyrosine as substrates were 6.7, 0.45, 4.96, and 0.02 s⁻¹, respectively. Therefore, aspartic acid, fumaric acid, phenylalanine, and tyrosine are bona fide substrates for LpAAL enzyme. Full article

(This article belongs to the Special Issue Applied Microorganisms and Industrial/Food Enzymes)

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Fermentation, Volume 9, Issue 1 (January 2023) – 78 articles

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