Sustainable production, biochemical and molecular characterization of thermo-and-solvent stable alkaline serine keratinase from novel Bacillus pumilus AR57 for promising poultry solid waste management.

The increasing amount of recalcitrant keratinous wastes generated from the poultry industry poses a serious threat to the environment. Keratinase have gained much attention to convert these wastes into valuable products. Ever since primitive feathers first appeared on dinosaurs, microorganisms have evolved to degrade this most recalcitrant keratin. In this study, we identified a promising keratinolytic bacterial strain for bioconversion of poultry solid wastes. A true keratinolytic bacterium was isolated from the slaughterhouse soil and was identified and designated as Bacillus pumilus AR57 by 16S rRNA sequencing. For enhanced keratinase production and rapid keratin degradation, the media components and substrate concentration were optimized through shake flask culture. White chicken feather (1% w/v) was found to be the good substrate concentration for high keratinase production when supplemented with simple medium ingredients. The biochemical characterization reveals astounding results which makes the B. pumilus AR57 keratinase as a novel and unique protease. Optimum activity of the crude enzyme was exhibited at pH 9 and 45 °C. The crude extracellular keratinase was characterized as thermo-and-solvent (DMSO) stable serine keratinase. Bacillus pumilus AR57 showed complete degradation (100%) of white chicken feather (1% w/v) within 18 h when incubated in modified minimal medium supplemented with DMSO (1% v/v) at 150 rpm at 37 °C. Keratinase from modified minimal medium supplemented with DMSO exhibits a half-life of 4 days. Whereas, keratinase from the modified minimal medium fortified with white chicken feather (1% w/v) was stable for 3 h only. Feather meal produced by B. pumilus AR57 was found to be rich in essential amino acids. Hence, we proposed B. pumilus AR57 as a potential candidate for the future application in eco-friendly bioconversion of poultry waste and the keratinase could play a pivotal role in the detergent industry. While feather meal may serve as an alternative to produce animal feed and biofertilizers.

Annona muricata assisted biogenic synthesis of silver nanoparticles regulates cell cycle arrest in NSCLC cell lines.

With plenteous accessible therapeutics, lung cancer endures a preeminent cause of the worldwide fatality. Apart from medical advancements, various plant parts are still used to treat cancer based on proven tradition. The present study focuses on analysing the anticancer efficacy of silver nanoparticles coupled with the aqueous leaf extract of Annona muricata. Nanoparticles play a momentous role in drug delivery due to their size and high surface to volume ratio and are with fewer side effect when phytofabricated. Annona muricata aqueous leaf extract mediated silver nanoparticles were characterized using UV visible spectrophotometer, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction and Zeta-sizer. Their antiproliferative potency was analysed by studying the mRNA and protein expressions of various apoptotic, anti-apoptotic and cell cycle regulatory genes. In addition, the cell cycle regulation was further confirmed using flow cytometry. The nanoparticles were found to be spherical shaped crystals with 80 ± 6.3 nm as average size and 6 µg/ml as inhibitory concentration 50 (IC50) on A549 human lung cancer cell line. It was observed that the nanoparticles efficiently induced apoptotic protein expression with a simultaneous suppression of anti-apoptotic protein. The results demonstrate activation of an intertwined intrinsic apoptotic pathway via caspases and the death receptors. The observations infer that the nanoparticles show excellent anticancer efficacy than the crude extract of Annona muricata leaves. Hence these nanoparticles would be a promising adjuvant for treating non- small cell lung cancer.