Microbial production of keratinase from Bacillus velezensis strain MAMA: A novel enzyme for eco-friendly degradation of keratin waste.

Keratin waste has become an increasingly serious environmental and health hazard. Keratin waste is mainly composed of keratin protein, which is one of the most difficult polymers to break down in nature and is resistant to many physical, chemical, and biological agents. With physical and chemical methods being environment damaging and costly, microbial degradation of keratin using keratinase enzyme is of great significance as it is both environment friendly and cost-effective. The aim of this study was to extract and purify keratinase from bacterial species isolated from the soil. Among the organisms, an isolate of Bacillus velezensis, coded as MAMA could break down chicken feathers within 72 hours (h). The isolated strain produced significant levels of keratinase in mineral salt medium by supplying chicken feathers as the sole source of nitrogen and carbon. Feather deterioration was observed with the naked eye, and enzyme activity was evaluated using a spectrophotometric assay. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and zymography results revealed that the keratinase protein produced by Bacillus velezensis had a molecular weight between 40 and 55 kilodalton (kDa).

A fungal based synthesis method for copper nanoparticles with the determination of anticancer, antidiabetic and antibacterial activities.

BACKGROUND: Biological procedures for the synthesis of copper nanoparticles (CuNPs) are eco-friendly, cost-effective, and easily scalable as compared to chemical and physical methods. METHODS: In the present study, a simple fungus based synthesis method was used for copper nanoparticles. After morphological and molecular characterization of fungal strains, Aspergillus niger strain STA9 was used for CuNPs synthesis. Particles synthesized by fungi were characterized by UV-visible spectrophotometer, FTIR, and Zetasizer. The MTT anti-cancer, anti-diabetic and antibacterial assays of CuNPs were performed. RESULTS: The CuNPs were produced at optimized conditions with a size of 500 nm, Z-average 398.2 nm, and 0.246 poly dispersion index. These particles were quantified at 480 nm and FTIR confirmed the existence of OH and -C=C- functional groups. MTT assay revealed that CuNPs have a significant cytotoxic effect against human hepatocellular carcinoma cell lines (Huh-7) with 3.09 µg/ml IC50 value. Alpha-glucosidase inhibition showed that CuNPs have a moderate antidiabetic effect. The agar well antibacterial effect indicated 19, 21, 16, 20, and 17 mm zone of inhibition against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Micrococcus luteus and Bacillus subtilis respectively. CONCLUSION: Such biomedical applications of CuNPs reveal the importance of a targeted drug delivery system.

Biodegradation of Poly(3-hydroxybutyrate) and Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by Newly Isolated Penicillium oxalicum SS2 in Soil Microcosms and Partial Characterization of Extracellular Depolymerase.

A fungus, designated as strain SS2 able to degrade aliphatic polyesters, poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), was isolated from soil. Strain SS2 was identified through rDNA gene sequencing and showed maximum closeness to Penicillium oxalicum. The newly isolated P. oxalicum strain SS2 had completely degraded PHB and PHBV both in emulsion and films form within 36-48 h at 30 °C. Furthermore, P. oxalicum SS2 degraded PHB and PHBV films in soil environment in lab-built soil microcosms within 1 week. The polymer films were evaluated for changes after degradation through scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC) and Fourier Transform Infrared spectroscopy (FTIR). The PHBV depolymerase enzyme was purified to homogeneity through column chromatography and molecular mass was found approximately 36 kDa. The depolymerase was stable over a wide range of temperature (15-60 °C) and pH (3.0-8.0) with optimum 40 °C and pH 5.0. The enzyme activity was significantly affected by various metal ions and surfactants. The enzyme activity was strongly enhanced in the presence of divalent cationic metal Cu2+ while inhibited by Zn2+ and non-polar detergents Tween 20 and Tween 60. Finally, it is concluded that P. oxalicum strain SS2 has profound degradation capabilities, and can be applied for the treatment of plastic-contaminated environments.

Biosynthesis, Characterization, and Biological Activities of Iron Nanoparticles using Sesamum indicum Seeds Extract.

BACKGROUND: Iron nanoparticles (FeNPs) have got many biomedical and health applications because of biocompatible and nontoxic nature to humans. OBJECTIVE: To synthesize the FeNPs using natural sources. MATERIALS AND METHODS: In this study, simple and economical procedure was adopted for FeNPs synthesis. Sesame seeds were processed to obtain seed extract as a biological material for FeNPs production. FeNPs were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopic. RESULTS: The average diameter of these FeNPs was 99 nm. These nanoparticles showed significant anti-typhoid activity (30 mm zone of inhibition) as compared to ciprofloxacin (32 mm) as standard. Furthermore, in vitro alpha-amylase inhibitory assay also showed moderate antidiabetic activity with more than 50% inhibition. CONCLUSION: This study would be helpful in understanding of nanoparticles synthesis from natural sources and ultimately will be used as potential alternative therapeutic agents. SUMMARY: Iron nanoparticles (FeNPs) were synthesized by Sesamum indicum seedsFeNPs were characterized by scanning electron microscope with average diameter of 99 nmThese FeNPs are effective against Salmonella typhi, a causative agent of typhoidThese FeNPs can be used as antidiabetic agent. Abbreviations used: FeNPs: Iron Nano Particles; SEM: Scanning Electron Microscopy; MIC: Minimum Inhibitory Concentration; S. indicum: Sesamum Indicum.

Degradation of polyester polyurethane by a newly isolated soil bacterium, Bacillus subtilis strain MZA-75.

A polyurethane (PU) degrading bacterial strain MZA-75 was isolated from soil through enrichment technique. The bacterium was identified through 16S rRNA gene sequencing, the phylogenetic analysis indicated the strain MZA-75 belonged to genus Bacillus having maximum similarity with Bacillus subtilis strain JBE0016. The degradation of PU films by strain MZA-75 in mineral salt medium (MSM) was analyzed by scanning electron microscopy (SEM), fourier transform infra-red spectroscopy (FT-IR) and gel permeation chromatography (GPC). SEM revealed the appearance of widespread cracks on the surface. FTIR spectrum showed decrease in ester functional group. Increase in polydispersity index was observed in GPC, which indicates chain scission as a result of microbial treatment. CO2 evolution and cell growth increased when PU was used as carbon source in MSM in Sturm test. Increase in both cell associated and extracellular esterases was observed in the presence of PU indicated by p-Nitrophenyl acetate (pNPA) hydrolysis assay. Analysis of cell free supernatant by gas chromatography-mass spectrometry (GC-MS) revealed that 1,4-butanediol and adipic acid monomers were produced. Bacillus subtilis strain MZA-75 can degrade the soft segment of polyester polyurethane, unfortunately no information about the fate of hard segment could be obtained. Growth of strain MZA-75 in the presence of these metabolites indicated mineralization of ester hydrolysis products into CO2 and H2O.