Preparative Biochemistry & Biotechnology最新文献

The present study has investigated the interactions of the phytochemicals present in sugarcane bagasse (SCB) with alcohol dehydrogenase (ADH1) enzyme in Saccharomyces cerevisiae using molecular simulations. ADH1 catalyzes the reduction of acetaldehyde to ethanol. The metabolic hindrance induced by phytochemicals can adversely affect kinetics and yield of ethanol fermentation. The phytochemicals in SCB biomass were detected using LC-ESI-MS/QTOF analysis after dilute acid/alkali pretreatment and extraction using methanol and acetonitrile. Molecular docking simulation revealed high binding affinity of four phytochemicals for ADH1 enzyme due to low binding energies and inhibition constants: chlorogenic acid (-8.64 kcal/mol, 0.464 μM), apigenin (-7.72 kcal/mol, 2.2 μM), diosmetin (-7.47 kcal/mol, 3.37 μM), and caffeic acid (-7.03 kcal/mol, 7.07 μM). The molecular dynamics simulations showed that root mean square deviation (RMSD) values of the complexes of chlorogenic acid (0.22 nm) and apigenin (0.27 nm) were significantly smaller than apoprotein (0.37 nm), which indicates their stability. The root mean square fluctuation (RMSF) value of active site residues of the phytochemical complexes (chlorogenic acid = 0.15 nm, apigenin = 0.13 nm) was also smaller than that of apoprotein (0.17 nm). These results clearly indicate that phytochemicals can hinder metabolic pathway of S. cerevisiae due to preferential binding to ADH1.

Probiotics are microorganisms that confer health benefits to the host, and a growing body of research has verified that the comprehensive development and application of probiotic resources will have a significant positive impact on humanity. As an important and typical type of prebiotic, polysaccharides are high-molecular-weight biopolymers connected via glycosidic linkages, possessing excellent physicochemical properties and bioactivities. However, the synergistic bioactivity and application of polysaccharide-based prebiotics and probiotics have not yet received sufficient attention. Therefore, from the perspective of potential applications in animal feed, foods, and medicines, and considering that the sole use of probiotics or prebiotics often fails to achieve satisfactory outcomes, this study aims to explore the synergistic bioactivities and applications of polysaccharide-based prebiotics and probiotics. It was found that the co-supplementation of polysaccharides and probiotics shows significant promise for enhancing the growth and performance of animals, improving the flavor, texture, taste, and nutrition of foods, and preventing, relieving, and treating disease symptoms (such as obesity, inflammation, aging, and liver injury). Concurrently, it is necessary to consider the types, dosage ratios, and administration methods of polysaccharides and probiotics during their combined utilization.

IRAK-4 plays a crucial role in autoimmune diseases, cancer and severe infections like sepsis. Inhibition of IRAK-4 may help manage these conditions. This study synthesized and evaluated four novel compounds (IGYZT01046, IGYZT01058, IGYZT01066, and IGYZT01068) for their IRAK-4 inhibitory potential. Molecular docking results showed all compounds had strong binding affinities for IRAK-4, with binding energies below -9.5 kcal/mol, indicating favorable interactions. Enzyme profiling confirmed their potential to target kinase enzymes, including IRAK-4. The compounds were synthesized and their structures were verified by NMR spectroscopy. Among them, IGYZT01058 was the most potent inhibitor, with an IC₅₀ value of 5.32 nM in biochemical assays. All compounds displayed significant inhibitory activity with IC₅₀ values below 100 nM, making them suitable for further development. In silico ADME predictions indicated promising pharmacokinetic properties, including good intestinal absorption and blood-brain barrier penetration. Overall, the study confirms that all four compounds as strong IRAK-4 inhibitors, with IGYZT01058 standing out as the most potent, suggesting its potential as a therapeutic agent for autoimmune diseases and sepsis.

Stachys antalyensis, an Anatolian endemic species, was investigated for its phenolic composition and in vitro bioactivities. Methanolic and aqueous extracts were prepared by ultrasound-assisted extraction and analyzed using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The methanolic extract exhibited higher total phenolic content (TPC; 58.29 mg gallic acid equivalents (GAE)/g) and total flavonoid content (TFC; 19.30 mg rutin equivalents (RE)/g) than the aqueous extract (28.72 mg GAE/g and 5.26 mg RE/g, respectively). Verbascoside (7961 µg/g) and chlorogenic acid (5358 µg/g) were the major constituents. In antioxidant assays, the methanolic extract showed stronger activity, with EC₅₀ or IC₅₀ values of 1.31 mg/mL in the phosphomolybdenum assay, 0.86 mg/mL in the cupric ion reducing antioxidant capacity assay (CUPRAC), 0.67 mg/mL in the ferric reducing antioxidant power assay (FRAP), and 4.19 mg/mL in the 2,2-diphenyl-1-picrylhydrazyl assay (DPPH), while the aqueous extract was more effective in ferrous ion chelation (IC₅₀: 1.14 mg/mL). The methanolic extract inhibited α-glucosidase (IC₅₀: 1.28 mg/mL), tyrosinase (IC₅₀: 1.06 mg/mL), and acetylcholinesterase (IC₅₀: 1.61 mg/mL). Cytotoxicity assays on human lung carcinoma (A549) and mouse fibroblast (L929) cell lines showed low toxicity between 250-2000 µg/mL, with cell viability ≥80% for A549 and ≥69% for L929 at 2000 µg/mL after 48 h. Overall, S. antalyensis is a phenolic-rich natural source with antioxidant and enzyme inhibitory potential.

The study on plant-derived antioxidant peptides is currently receiving increased attention due to their natural origin, safety, and potential applications in nutraceuticals, functional foods, and pharmaceuticals. The Zingiberaceae family widely used traditional medicinal plants; include Kaempferia parviflora (black ginger) and Zingiber officinale (ginger), however, their bioactive peptide composition remains largely unexplored. In this study, proteins were extracted from Z. officinale and K. parviflora using four different pH-based buffers and subsequently filtered through ultrafiltration membranes with 10 kDa and 3 kDa cutoffs. The antioxidant activities of crude extracts, 10 kDa, and 3 kDa filtrates were evaluated using DPPH, FRAP, ABTS, and NOS assays. The highest antioxidant activity was observed in 3 kDa peptides filtrate extracted with Tris HCl pH 8.0 buffer than crude and 10 kDa in all the assays. Using HPLC and MALDI-ToF MS, multiple bioactive sequences were identified common to both species (SVAGRAQGM, MWPFPSDK and MNEYLLPK) alongside unique peptides such as QAKSQGGSN, QNAHHPSPK, PRGSPRTEYE AARR and ADPPHIHASL from Z. officinale and K. parviflora respectively were identified by MALDI-TOF MS. These peptides are associated with numerous biological processes, including metabolic, hydrolytic, antibacterial, and antifungal properties. This finding indicates that Z. officinale and K. parviflora are rich sources of antioxidant peptides, offering promising formulations based on natural products.

The novel edible antimicrobial gelatin film was developed with extracts of Garcinia cambogia (GC), Myristica fragrans rind (NM), and Allium sativum peel (GP) to extend the shelf life of Tuna. The strongest inhibition zone for of 20 mm was observed against Staphylococcus aureus and 22 mm against Escherichia coli with the extracts. Gelatin films containing 1%, 2%, and 3% (w/v) extracts were evaluated for physicomechanical properties and preservation efficacy. The 3% antimicrobial film exhibited the lowest oxygen transmission rate (324.76 ± 8.75^d cm3/m2.24h.0.1 MPa), water vapor permeability rate (995.40 ± 15.4^cg/m2.24h), highest tensile strength (3.36 ± 0.11^d MPa) and elongation at break (138.54 ± 1.3^d %). Tuna fillets packed with antimicrobial films were stored at -4 °C for 13 days. Tuna preserved with the 3%(w/v) extract film exhibited a slower rise in pH (6.49), higher water-holding capacity, and reduced lipid oxidation. TBARS values were observed as (2.01 mg MDA/100 mg) for 3% film and found to be increased upto 3.53 mg MDA/100 mg on day 13 for tuna without film. Microbial growth was effectively suppressed, with delayed yeast and mold development.

Post-harvest fungal diseases are major contributors to crop losses in fruits and vegetables, and although chemical fungicides are commonly used, they pose significant environmental and health risks. Biological alternatives, such as Plant Growth Promoting Rhizobacteria (PGPR), have gained attention for safer disease control. In this study, a total of 154 Bacillus and Pseudomonas strains were screened for antifungal activity against four common post-harvest fungal pathogens (Alternaria papavericola, Botrytis cinerea, Monilinia laxa, and Penicillium italicum) using dual culture and agar well diffusion assays, alongside lytic enzyme activity assessment. Thirty-five strains demonstrated effective antagonistic activity. Laboratory-scale production optimization of Pseudomonas chlororaphis P-105-b-a, the most effective strain, was carried out using Response Surface Methodology, achieving a viable cell count of 3.3 x 10¹⁰ cfu/mL in modified King's B Broth containing 5% glycerol and 2% dry yeast. This study provides insights for the development of PGPR-based biopreparations to enhance post-harvest disease management.

Polyhydroxyalkanoates (PHA) are biodegradable polymers synthesized by microorganisms under nutrient-deficient conditions. Coconut water, an abundant yet often discarded agro-industrial by-product, is a cost-effective and environmentally friendly substrate rich in carbohydrates such as glucose, fructose, and sucrose. PHAs are typically produced using costly and unsustainable carbon sources. This study investigated the effects of media sterilization methods and carbon-to-nitrogen (C/N) and carbon-to-phosphorus (C/P) ratios on PHA production by Cupriavidus necator KCTC 2649 using coconut water. Among the sterilization methods tested (fresh, autoclaved, filter-sterilized, and synthetic), filter-sterilized media supported the highest PHA yield (4.31 g/L; 0.431 g/g sugar). Optimization of nutrient ratios showed that both C/N and C/P strongly influenced biomass accumulation and polymer yield. Notably, a C/N ratio of 50 combined with a C/P ratio of 10 resulted in maximum biomass growth together with the highest PHA production (5.85 g/L; 59.57% wt/wt; 0.29 g/g sugar). Nutrient limitation at high C/N and C/P ratios promoted PHA accumulation. These findings highlight the potential of coconut water as a sustainable substrate for biomass generation and PHA production by C. necator KCTC 2649.

The cyanobacterial strain BTA-330 was evaluated for its potential to produce exopolysaccharides (EPS) under nitrogen-deprived photoautotrophic conditions. The strain was initially identified through a polyphasic approach as Desmonostoc sp., BTA-330. The strain depicted biomass concentration of 1.23 g/L and total EPS of 367.87 ± 5.4 mg L^-1 in 30 days with capsular-EPS (CPS) and released-EPS (RPS) of 218.67 ± 2.5 and 149.2 ± 2.9 mg L^-1, respectively. Biomass composition analysis (in % w/w, DCW) showed total protein of 34% with 26.02% of total proteins comprising phycobiliproteins, followed by carbohydrates (32%), lipids (16%), nucleic acid (8%), other pigments (1.7%), and ash (7%). Kinetic studies revealed both CPS and RPS as secondary metabolites with maximum accumulation during the stationary phase of growth. The analysis of EPS composition showed abundant carbohydrate content of 80% (w/w, dry cell weight), followed by protein and nucleic acids. The subsequent characterization of both EPS using SEM, FTIR, and rheometer revealed the morphology, distinct functional groups, and their pseudoplastic behaviors, respectively. Further analysis demonstrated significantly high flocculating rate (39.4 ± 1.3 to 51.78 ± 1.3), DPPH scavenging (37.74 ± 1.5 to 39.76 ± 1.3), and hydroxyl ion scavenging (57.46 ± 1.2 to 69.53 ± 1.2) activities. Thus, Desmonostoc sp. BTA-330 is a unique source of EPS with potential applications in the food and pharma industries.

Microalgae-derived extracellular polysaccharides (EPSs) have emerged as a promising biological macromolecule for its application in pharmaceutical and biotechnological fields due to its diverse physicochemical and biological activities. In this study, an isolated microalgae (Asterarcys quadricellulare) was cultured in photobioreactor under the light condition by maintaining 14:10 photoperiod to produce EPSs. The yield of EPSs was found 0.392 ± 0.027 gL^-1. The biochemical analysis of extracted EPSs had shown the presence of uronic acid (0.42 ± 0.05%), phosphate (0.312 ± 0.013%), sulfate (0.531 ± 0.04%), and carbohydrates (60.33 ± 0.02%) containing glucose and galactose with a ratio of 3.24:1. FTIR analysis of EPSs revealed characteristic glycosidic bond between sugar monomer at 880 and 834 cm^-1. Therefore, extracted EPS was a complex heteropolysaccharide structure. Surface morphology of EPSs revealed the presence of a large number of symmetrical and regular filamentous repeating units. XRD analysis had shown the crystalline nature of extracted EPSs with crystallinity index of 51.73%. Antimicrobial activity of EPSs was evaluated against Bacillus subtilis (gram positive) and Escherichia coli (gram negative) bacteria. Escherichia coli had showed 46.67 ± 0.002% growth inhibition and 33.3 ± 2.5% (P < 0.01) reduction in the viable cell count compared to the negative control. Results demonstrated the promise of microalgal EPSs in the biotechnology and pharmaceutical sectors for selective antimicrobial application.