Aug 2026· Preparative Biochemistry & Biotechnology· pp.
1-12
· 0 citations· 23 references
Medicine
Abstract
L-Asparaginase is an important enzyme with therapeutic applications. Current commercial enzymes from E. coli and Erwinia chrysanthemi have limitations, such as high glutaminase activity, creating a need for more stable alternatives. This study aimed to isolate and optimize the production of L-Asparaginase from native, halotolerant Bacillus subtilis strains (DAR and D6A) isolated from central Iran, to find an alternative source for this therapeutically important enzyme. The enzyme was initially isolated using polyethylene glycol (PEG) precipitation. Key factors affecting enzyme production were screened using the Plackett-Burman design and subsequently optimized via the Box-Behnken response surface methodology. PEG precipitation at concentrations of 15-20% for PEG 4000/6000 and 10-15% for PEG 8000/10000 was most effective for initial enzyme separation, yielding specific activities of 4.8 U/mg and 5.2 U/mg for strains DAR and D6A, respectively. Optimization revealed that the most influential factors for maximum L-Asparaginase production were 17.6 g/L NaCl, 4.99 g/L KH2PO4, and 10 g/L asparagine for strain DAR, and 1.49 g/L glucose, 10 g/L NaCl, and 9.98 g/L asparagine for strain D6A. The isolated halotolerant B. subtilis strains are capable of producing L-Asparaginase. PEG precipitation is a suitable method for initial purification, and statistical optimization successfully identified the critical culture conditions to enhance enzyme yield significantly. These strains represent promising sources for the production of this clinically valuable enzyme.
Among the 20 isolates, one isolate was identified as Brevibacillus parabrevis PS12, representing the first report from Iraqi soil, which contributed to an increase in bacterial biomass which led to a rise in the specific activity of arginase.
Ayah Muwafaq Hussein, Aqeel Mohammed Majeed Al-Ezee, Zaid Raad Abbas· Journal of the College of B...· 0 citations
Niacin (vitamin B3) is a high-value chemical widely used in the pharmaceutical and food industries. In this study, a recombinant Escherichia coli strain expressing nitrilase from Pseudomonas putida CGMCC3830 was evaluated for the whole-cell biotransformation of high-concentration 3-cyanopyridine to niacin. Molecular docking predicted important substrate-interacting residues, including T135, K131, F202, and W166. Under optimized conditions (160 g/L wet cells, pH 8.5), free whole cells completely hydrolyzed 3.0 M 3-cyanopyridine within 8 h. To enhance operational stability, the cells were immobilized in sodium alginate beads containing green zeolite. The resulting catalyst achieved complete conversion of 1.4 M 3-cyanopyridine within 4 h and maintained 96.5% conversion after six cycles. These findings demonstrate the potential of this system for future industrial applications.
Zaiheng Wu, Jingyi Zhou, Bo Fan et al.· Processes· 0 citations
Background Prunin is scarce in nature and suffers from low extraction efficiency, and industrial-scale production of prunin and L-rhamnose remains technically inadequate. Therefore, developing an α-L-rhamnosidase capable of efficient and specific naringin hydrolysis is of great practical significance. Methods An α-L-rhamnosidase gene from Aspergillus nidulans was expressed recombinantly in E. coli Rosetta (DE3). Expression conditions were optimized, and random mutagenesis coupled with high-throughput screening was performed to obtain a beneficial mutant (R11). Enzyme properties were characterized, and fed-batch fermentation in a 2-L bioreactor was carried out for scale-up. Results The purified recombinant enzyme (120.7 kDa) showed optimal activity at 75 °C and pH 5.0, with a Km of 5.23 mM toward pNPR. A key mutant, R11, exhibited 22.2% higher relative activity than the wild type. After tank fermentation, enzyme activities of both wild-type and R11 were increased approximately two-fold, and the conversion rate of naringin to prunin by R11 was 2.77-fold higher than that of the unoptimized wild-type control. Conclusion The recombinant α-L-rhamnosidase possesses broad temperature adaptability and excellent catalytic properties. This study provides a novel integration of random mutagenesis and bioreactor scale-up for efficient naringin-to-prunin bioconversion, laying a theoretical foundation for industrial production.
Chuncheng Wang, Li Liang, Bei Ni et al.· Frontiers in Microbiology· 0 citations
Overall, UzMU25 exhibited preliminary enzymatic, antagonistic, and biofilm-forming characteristics of biotechnological interest, but whole-genome antimicrobial-resistance screening and more comprehensive phenotypic and toxicological evaluations are required before the strain can be recommended for probiotic or other practical applications.
Luiza Tagayeva, K. Normurodova, S. Jabborov et al.· Microorganisms· 0 citations
White biotechnology has benefited greatly from the employment of highly specific enzymes in a range of industrial processes. The choice of robust bacterial strains with the appropriate enzymatic profiles is critical for commercial viability. The present study was undertaken for isolation, identification and screening of native bacterial strains for production of industrially important hydrolytic enzymes. Morphological, and biochemical characterization has revealed five novel isolates of Bacillus licheniformis. These isolates showed a wide physiological versatility, such as growth at the temperature range of 30.0-55.0°C and resistance to high salinity (2.0-10.0%). All isolates produced significant extracellular amounts of main hydrolytic enzymes; protease, α-amylase, glucoamylase, cellulase and pectinase with varying titers. Quantitative enzyme assays revealed protease activity ranging from 45.2-78.6 U/mL, amylase activity from 32.5-65.3 U/mL, and cellulase activity from 18.7-42.1 U/mL. These strains demonstra
Tayyaba Asif, Maria Ghani, Muhammad Yonus Ahmed· International Journal of Bio...· 0 citations
Lipases are important enzymes in the esterase family that hydrolyze ester bonds in triglycerides, producing simpler molecules. This property makes them valuable in biotechnology and environmental cleanup. In this study, lipase-producing bacteria were isolated and characterized from petroleum-contaminated soil to establish a cost-effective platform for enzyme production and bioremediation. Among the recovered isolates, Serratia liquefaciens AB1 exhibited the highest lipolytic activity and was therefore selected for further investigation. The influence of various inducer oils and agro-industrial residues on enzyme production was systematically assessed. In addition, fermentation parameters were optimized through the evaluation of different carbon and nitrogen sources to enhance lipase yield. Waste frying oil was identified as the most effective inducer, while glucose and yeast extract supported optimal enzyme production. The enzyme lipase AB1 was fully purified using CM-Sephadex C-50 chromatography, Sephadex G-100 and further characterized by SDS-PAGE, kinetic studies, and stability assays. Purification of the enzyme resulted in a specific activity of 610.92 U/mg, corresponding to a 9.42-fold increase in purity with an overall recovery of 76%. The enzyme exhibited an apparent molecular mass of approximately 64 kDa. It demonstrated optimal catalytic activity at 60 °C and pH 8 and retained substantial stability at this temperature for up to 120 min. Kinetic analysis revealed a low Km value of 30 µM, indicating strong substrate affinity, along with a Vmax of 23.89 U/mL, reflecting a high catalytic efficiency under the tested conditions. Enzyme activity was enhanced by Ca2+, Na+, and Ba2+, but inhibited by Mn2+ and Hg2+. These findings demonstrate the favorable biochemical properties of the purified lipase and provide a basis for future investigations into its potential application as a biocatalyst for bioremediation.
A. Baruwa, K. Permaul· Applied microbiology· 0 citations
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