Appl. Biosci., Volume 3, Issue 2 (June 2024) – 9 articles

The nucleus accumbens shell (NAcSh) is a major structure associated with distinct aspects of reward and mnemonic information encoding, relying on spatial data to define optimal behavioral strategies. Chronic pain-derived striatal plasticity is considered one underpinning cause of working memory (WM) impairments. However, it is unclear how the NAcSh is involved in these spatial deficits. To address this, we evaluated the impact of unilateral local NAcSh electrical lesions during the execution of a food-reinforced eight-shaped spatial alternation WM task. Behavioral performance was assessed in rats after the onset of the neuropathic pain model—spared nerve injury (SNI). Our findings indicate that the induction of SNI and/or NAcSh lesions did not significantly impact the animals’ performance accuracy or motor activity during the execution of the behavioral task, but altered their response latency patterns. In addition, these manipulations did not induce significant antinociceptive effects. Collectively, these results suggest that the NAcSh may participate in specific aspects of spatial information integration and processing under neuropathic pain conditions. Full article

Pulse proteins are playing significant roles in the alternative protein space due to the demand for foods produced in an environmentally sustainable manner and, most importantly, due to the demand for foods of nutritious value. There has been extensive research to mimic animal-derived meat texture, flavour, mouthfeel, etc. However, there is still the perception that many of the plant-based proteins that have been texturized to mimic meat are still highly processed and contain chemicals or preservatives, reducing their appeal as being healthy and precluding any sustainable benefits. To counter this notion, the biotransformation of pulse proteins using enzymes or fermentation offers unique opportunities. Thus, this review will address the significance of pulse proteins in the alternative protein space and some of the processing aids leading to the isolation and modification of such protein concentrates in a sustainable manner. Fermentation-based valorization of pulse proteins will also be discussed as a “clean label” strategy (further adding to sustainable nutritious plant protein production), although some of the processes like the extensive use of water in submerged fermentation need to be addressed. Full article

Thermoplastics used to construct a variety of patient medical devices can become contaminated by harmful bacteria. We investigated whether two different Bacillus species recovered from patient radiation therapy thermoplastic masks could similarly contaminate thermoplastic material used to construct patient orthoses (splints). Bacillus bacteria form dormant spores, which have been shown to enhance its attachment to thermoplastics. Bacterial attachment and recovery were examined using an orthotic thermoplastic with an anti-stick coating being compared to uncoated material used in radiation therapy applications. Triplicate sample squares were seeded with a saline suspension of either B. cereus (MAB03F) or B. megaterium (DAB01F) containing a similar number of spores. Squares were subsequently sampled at 1 h, 1 week, 2 weeks, 4 weeks, and 8 weeks. The number of recovered bacteria was counted. Differences in material hydrophobicity were determined by water contact angle analysis. Both Bacillus species attached to each material within 1 h, and their spores were recovered at 8 weeks. However, a decreasing trend in adhesion, over time, was noted to the coated material with an opposite increasing trend in the uncoated material. Decreased Bacillus species spore adhesion to coated material with a lower hydrophobicity suggests a greater potential for spore transfer to patients wearing contaminated orthoses. Full article

Synucleinopathies, typified by Parkinson’s disease (PD), entail the accumulation of α-synuclein (αSyn) aggregates in nerve cells. Various αSyn mutants, including the αSyn A53T variant linked to early-onset PD, increase the propensity for αSyn aggregate formation. In addition to disrupting protein homeostasis and inducing proteostatic stress, the aggregation of αSyn in PD is associated with an imbalance in iron metabolism, which increases the generation of reactive oxygen species and causes oxidative stress. This study explored the impact of αSyn A53T expression in transgenic hairy roots of four medicinal plants (Lobelia cardinalis, Artemisia annua, Salvia miltiorrhiza, and Polygonum multiflorum). In all tested plants, αSyn A53T expression triggered proteotoxic stress and perturbed iron homeostasis, mirroring the molecular profile observed in human and animal nerve cells. In addition to the common eukaryotic defense mechanisms against proteostatic and oxidative stresses, a plant stress response generally includes the biosynthesis of a diverse set of protective secondary metabolites. Therefore, the hairy root cultures expressing αSyn A53T offer a platform for identifying secondary metabolites that can ameliorate the effects of αSyn, thereby aiding in the development of possible PD treatments and/or treatments of synucleinopathies. Full article

Chitinases are biotechnologically relevant enzymes that can be applied in such different sectors as pharmaceutical, food, environmental management, the biocontrol of pests and in the paper and cellulose industry. Microorganisms as filamentous fungi are the most important source of these biomolecules. The fungus Aspergillus niveus produces extracellular chitinase when cultured under submerged fermentation using shrimp shells, a residue generated by the fish industry, as a carbon source, for 96 h at 30 °C and 100 rpm. The particle size and concentration of the shrimp shells affected enzyme production. The chitinase was purified until electrophoretic homogeneity through the use of a Sephadex G-100 chromatographic column. It is a monomeric glycoprotein with a molecular mass of 47 kDa estimated using SDS-PAGE and 49.3 kDa determined using gel filtration. The carbohydrate content was 22.8%. The best temperature and pH for enzyme activity were 65 °C and 6.0, respectively. Approximately 80% of the enzymatic activity was preserved at pH 4.0 and 5.0 for 48 h, and the half-life (t₅₀) was maintained for 48 h at 40 °C. Salts, EDTA and β-mercaptoethanol did not affect chitinase activity significantly, but organic solvents reduced it. The kinetic parameters determined using p-NPGlycNac were K_m of 2.67 mmol L⁻¹, V_max of 12.58 U mg of protein⁻¹, Kcat of 2.47 s⁻¹ and K cat/K_m of 0.93 s⁻¹ mmol L⁻¹. The A. niveus chitinase inhibited the growth of all fungal strains used, especially Trichoderma harzianum (MIC = 22.4 μg mL⁻¹) and Penicillium purpurogenum (MIC = 11.2 μg mL⁻¹). The chitinase produced by A. niveus presented interesting characteristics that indicate its potential of application in different areas. Full article

The utilization of microalgae as a green carbon source for chemical production has attracted attention for its potential use in sustainable and climate-friendly solutions. This study investigates the growth of Dunaliella salina, a unicellular green microalga, in response to salinity variations and water and seawater addition to compensate for evaporation in open cultures. The impact of continuous and non-continuous water addition, as well as seawater addition, on the growth of D. salina was analyzed though tank tests. The results showed that different water-addition methods did not significantly influence cell concentrations, indicating the organism’s resilience to salinity changes. Continuous water addition maintained stable salinity levels at 12%, but required continuous monitoring, while non-continuous addition reduced the intervention frequency. The overall results showed that a salinity range between 12 and 15% did not affect microalgae growth, suggesting flexibility in evaporation-loss compensation methods based on cultivation-system specifics and resource availability. Maintaining consistent biomass regardless of the water-addition method used suggests sustainable production within the tested salinity range, with seawater addition making microalgae cultivation more adaptable to regions with varying water availability. Further research, including outdoor pilot tests, is recommended to validate and extend these findings to natural environments. Full article

Growing demands for sustainable and ecological nanoparticle synthesis methods have incentivized the scientific community to develop new approaches to counteract these challenges. Green synthesis resorts to biocomponents obtained from plants, bacteria, fungi, and other organisms to synthesize nanostructures, with beneficial gains in the economic and ecological cost associated with the process, simplicity of the process, and resource efficiency. Moringa oleifera, a native plant originally from India with immense nutritive value, has long been used by researchers in the biosynthesis of nanoparticles. Leaves, flowers, bark, and seeds are among the “miracle tree” parts that can be used in nanoparticle green synthesis. Moringa oleifera seed cake, a by-product obtained from defatted seeds, is often overlooked due to its apparent low commercial value. The main objective of this review is to highlight the recent findings reported in the literature on nanoparticles/nanocomposites synthesized with seed cake biocompounds acting as reducing/capping agents. Furthermore, we analyzed the methods currently employed for the extraction of bioactive compounds. Moringa oleifera seed for industrial applications was also addressed. Full article

The emergence of bacteria resistant to bacteriophage (phage) infection may compromise the success and effectiveness of phage therapy. The aim of this study was to evaluate the in vitro antibacterial activity of five novel phages, as well as the emergence of bacterial resistance to phage infections. The antibacterial activity of lytic phages was evaluated against standard strains of Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25927), Enterococcus faecalis (ATCC 29212) and Staphylococcus aureus (ATCC 6538). Phages were initially grown in the presence of host bacteria in an exponential growth phase, then purified and titrated. In a second exposure, 20 μL of each phage was inoculated with 10⁶ CFU/mL of P. aeruginosa/E. coli/E. faecalis/S. aureus, separately. In a third exposure, resistant colonies were isolated, cultivated and exposed again to the phages. Bacterial colonies resistant to phage infection after the third exposure were evaluated for their susceptibility profile to different antibiotics via the diffusion disk technique. The diameters of the inhibition halos were evaluated with Image J software (version 1.54g) and the definition of the susceptibility profile to antibiotics was determined according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. In addition, fourteen cocktails with different phages were formulated to evaluate the emergence of a bacterial resistance to phage infections. The phages exhibited specificity for P. aeruginosa and did not infect E. coli, E. faecalis and S. aureus. The presence of bacterial colonies resistant to phage infection in the three successive exposures was identified, and the bacterial resistance to phage infection was confirmed in all phages titrated at 10⁸ PFU/mL, in four phages titrated at 10¹⁰ PFU/mL and in one phage titrated at 10¹³ PFU/mL. The development of a resistance to infection by phages (~10⁸ PFU/mL) did not change the susceptibility profile of P. aeruginosa to antibiotics and, when evaluating the emergence of a resistance to infection by phage cocktails (~10⁸ PFU/mL, ~10¹⁰ PFU/mL, ~10¹³ PFU/mL), bacterial resistance to phage infection was confirmed in all cocktails with phages titrated at 10⁸ PFU/mL, in ten cocktails with phages titrated at 10¹⁰ PFU/mL and in seven cocktails with phages titrated at 10¹³ PFU/mL. In conclusion, the presence of resistant P. aeruginosa colonies to phage infection after successive exposures was evidenced, although some phages at title ~10¹⁰ PFU/mL and ~10¹³ PFU/mL were effective in inhibiting the growth of resistant colonies. The development of resistance did not change the susceptibility profile of P. aeruginosa to antibiotics. Variants of P. aeruginosa that were resistant to phage infection were isolated and their resistance to infection via the phage cocktail was demonstrated regardless of the viral titer, although some cocktails at title ~10¹⁰ PFU/mL and ~10¹³ PFU/mL were effective in inhibiting the growth of resistant colonies. Despite the emergence of bacterial variants resistant to phage infection, new studies involving the applicability of phages in the control of infections must be conducted. Full article

Introduction: Mortality from acute radiation syndrome is frequently caused by hematopoietic or gastrointestinal radiotoxicity, the latter of which currently has no effective treatment. Transforming growth factor-beta 3 (TGF-β3) may decrease the severity of radiation-induced gastrointestinal damage in mice. In addition, treatment with TGF-β3 may alleviate radiation-induced fibrosis. Objectives: The current study aimed to investigate the effect of TGF-β3 treatment on acute and late radiotoxicity in whole body irradiated mice. Methods: C57BL/6J mice were total body irradiated with 8.5 Gy X-rays with or without shielding of one hind leg to alleviate hematopoietic radiotoxicity. The effects of intravenous TGF-β3 treatment were investigated. Body weight and pain expression were monitored. Intestine, lung, and liver tissues were preserved and analyzed. Alpha smooth muscle actin (α-SMA) expression in MRC-5 cells after 3.5 Gy X-irradiation combined with TGF-β3 treatment was analyzed using flow cytometry. Results: All total body irradiated animals died within ten days after irradiation. Ninety-three percent of femur-shielded mice survived until sampling or termination. No effect of TGF-β3 treatment was observed in either group. No increase in collagen content was detected in the lungs or liver from irradiated mice regardless of TGF-β3 treatment. In vitro, α-SMA expression increased synergistically after irradiation and TGF-β3 treatment. Conclusions: Shielding of the femur during total body irradiation decreased acute gastrointestinal radiation toxicity and increased survival. TGF-β3 treatment did not impact symptoms or survival. TGF-β3 treatment and irradiation increased α-SMA expression in MRC-5 cells synergistically. Full article