Evaluation of a novel purified and characterized alkaline protease from the extremophile Exiguobacterium alkaliphilum VLP1 as a detergent additive.

This study focused on the isolation and identification of a novel alkaline protease-producing strain from Lake Van, the largest soda lake on Earth. The objective was to purify, characterize, and investigate the potential application of protease in the detergent industry. Through a combination of classical and molecular methods, the most potent protease producer was identified as Exiguobacterium alkaliphilum VLP1. The purification process, involving ammonium sulfate precipitation, ultrafiltration, and anion exchange chromatography, resulted in a 45-fold purification with a yield of 6.4% and specific activity of 1169 U mg-1 protein. The enzyme exhibited a molecular weight of 69 kDa, a Km value of 0.4 mm, and a maximal velocity (Vmax ) value of 2000 U mg-1 . The optimum activity was observed at 40°C and potential of hydrogen (pH) 9, while the enzyme also exhibited remarkable stability in the ranges of 30-60°C and pH 9-12. Notably, this study represents the first report of an alkaline protease isolated and characterized from E. alkaliphilum. This study also highlighted the potential of the enzyme as a detergent additive, as it showed compatibility with commercial detergents and effectively removed blood and chocolate stains from fabrics.

Purification and characterization of Stenotrophomonas maltophilia chitinase with antifungal and insecticidal properties.

This study aimed to determine the ability of bacteria to produce the chitinase enzyme, purify, and characterize the enzyme from the isolate with the best activity, and determine the use of this purified enzyme as a biocontrol agent. The chitinolytic bacterium was identified as Stenotrophomonas maltophilia. The chitinase enzyme was purified 1.4 times at a 30% ammonium sulfate concentration with a yield of 40.7%. Following partial purification, the enzyme was purified by ion-exchange chromatography using HiPrep Q XL 16/10 column and HiPrep™ 26/10 desalting column with 25.34% and 18.12% yields, respectively. It was calculated that the purified enzyme had a molecular weight of 52 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The optimum activity of the enzyme was determined at 50 °C and pH 7.0. Enzyme activity was most induced by Fe2+, while it was most inhibited by Zn2+ at 5 mM concentration. Km and Vmax values of the enzyme for colloidal chitin were calculated as 1.6419 mg/mL and 16.129 U/mg, respectively. The purified chitinase was used as a biocontrol agent against the fungus Fusarium oxysporum and potato beetle Leptinotarsa decemlineata. The enzyme was shown to be effective in reducing the growth of fungus and causing disruption of the chitin structure of potato beetle.

A novel carotenoid from Metabacillus idriensis LipT27: production, extraction, partial characterization, biological activities and use in textile dyeing.

The present study reports the production, extraction, partial characterization, biological activities and use in textile dyeing of an orange pigment from Metabacillus idriensis strain LipT27 (MN818522.2). Pigment production occurred with 400 µg carotenoid/g biomass yield. Characterization of the methanol extracts of pigment by UV-Visible spectrophotometry, TLC, NMR, and FTIR indicated that the pigment was a carotenoid group pigment. The pigment exhibited antibacterial activity against Yersinia enterocolitica, Staphylococcus aureus, and Escherichia coli and antioxidant potential in DPPH and ABTS assays. In addition, the crude pigment was used in dyeing cotton fabrics. The first carotenoid from M. idriensis, which has strong antibacterial and antioxidant properties and also has the potential to be used as a dyeing agent for textiles, suggests that it can be used as a natural colorant substitute to synthetic dyes.

Recent advances in nanoparticles as antibacterial agent.

Recently, the rapid increase in antibiotic-resistant pathogens has caused serious health problems. Researchers are searching for alternative antimicrobial substances to control or prevent infections caused by pathogens. Different strategies are used to develop effective antibacterial agents, and in this respect, nanoparticles are undoubtedly promising materials. Nanoparticles act by bypassing drug resistance mechanisms in bacteria and inhibiting biofilm formation or other important processes related to their virulence potential. Nanoparticles can penetrate the cell wall and membrane of bacteria and act by disrupting important molecular mechanisms. In combination with appropriate antibiotics, NPs may show synergy and help prevent the developing global bacterial resistance crisis. Furthermore, due to characteristics such as enhanced biocompatibility and biodegradability, polymer-based nanoparticles enable the development of a wide range of medical products. Antibacterial applications of nanoparticles range from antimicrobial synthetic textiles to biomedical and surgical devices when nanoparticles are embedded/loaded/coated into different materials. In this review, the antibacterial mechanisms of nanoparticles and their potential for use in the medical field are discussed.

Purification and characterization of a novel extracellular, alkaline, thermoactive, and detergent-compatible lipase from Aeromonas caviae LipT51 for application in detergent industry.

Lipase producer bacterium isolated from Erzurum was identified as Aeromonas caviae LipT51 (GenBank ID: MN818567.1) by 16S rDNA sequencing and conventional methods. Extracellular lipase was purified by ammonium sulphate precipitation, centrifugal filtration, and anion-exchange chromatography resulting in 6.1-fold purification with 28% final yield. Molecular weight was 31.6 kDa on SDS-PAGE. Lipase was stable over a broad range of pH (6-11) and temperature (25-70 °C), and showed optimum activity at pH 9 and 60 °C. Km and Vmax for pNPP hydrolysis were 0.88 mM and 34.2 U/mg protein, respectively. Ba2+, Ca2+, Co2+, Cu2+, Fe3+, and Mg2+ increased activity, while Mn2+, Mo2+, Ni2+, Zn2+, and other additives partially decreased. Activity and stability increased with laundry detergent and slightly decreased with handwash and dishwashing detergents. Alkaline and thermostable lipase from newly isolated A. caviae has been shown for the first time to be remarkably compatible with laundry detergent and improve washing performance by enhanced oil-stain removal.

Optimization of rhamnolipid production by Pseudomonas aeruginosa OG1 using waste frying oil and chicken feather peptone.

In the present study, production of rhamnolipid biosurfactant by Pseudomonas aeruginosa OG1 was statistically optimized by response surface methodology. Box-Behnken design was applied to determine the optimal concentrations of 52, 9.2, and 4.5 g/L for carbon source (waste frying oil), nitrogen source (chicken feather peptone), and KH2PO4, respectively, in production medium. Under the optimized cultivation conditions, rhamnolipid production reached up to 13.31 g/L (with an emulsification activity of 80%), which is approximately twofold higher than the yield obtained from preliminary cultivations. Hence, rhamnolipid production, noteworthy in the literature, was achieved with the use of statistical optimization on inexpensive waste materials for the first time in the present study.

Optimization of culture conditions for Aspergillus sojae expressing an Aspergillus fumigatus α-galactosidase.

Using Response Surface Methodology, carbon and nitrogen sources and agitation speed for cultivation of Aspergillus sojae expressing the α-galactosidase gene, aglB of Aspergillus fumigatus IMI 385708 were optimized. Compared to cultivation in modified YpSs medium, cultivation in 250-mL Erlenmeyer flasks agitated at 276 rpm and containing 100 mL of optimized medium consisting of 10.5% molasses (w/v) and 1.3% NH(4)NO(3) (w/v), 0.1% K(2)HPO(4), and 0.005% MgSO(4)·7H(2)O achieved a 4-fold increase in α-galactosidase production (10.4 U/mL). These results suggest the feasibility of industrial large scale production of an α-galactosidase known to be valuable in galactomannan modification.