| Summary: | Keratinases are considerably gaining momentum in green technology because of their endowed robustness and multifaceted application potentials, such as keratinous agro-wastes valorization. Therefore, the production of novel keratinases from relatively nonpathogenic bacteria grown in agro-wastes formulated medium is cost-effective, and also imperative for the sustainability of thriving bioeconomy. In this study, we optimized keratinase production by <i>Bacillus</i> sp. Nnolim-K1 grown in chicken feather formulated medium. The produced keratinase (KerBNK1) was biochemically characterized and also, the keratinase-encoding gene (<i>kerBNK1</i>) was amplified and sequenced. The optimal physicochemical conditions for extracellular keratinase production determined were 0.8% (<i>w/v</i>) xylose, 1.0% (<i>w/v</i>) feather, and 3.0% (<i>v/v</i>) inoculum size, pH 5.0, temperature (25 °C) and agitation speed (150 rpm). The maximum keratinase activity of 1943.43 ± 0.0 U/mL was achieved after 120 h of fermentation. KerBNK1 was optimally active at pH and temperature of 8.0 and 60 °C, respectively; with remarkable pH and thermal stability. KerBNK1 activity was inhibited by ethylenediamine tetra-acetic acid and 1,10-phenanthroline, suggesting a metallo-keratinase. The amplified <i>kerBNK1</i> showed a band size of 1104 bp and the nucleotide sequence was submitted to the GenBank with accession number MT268133. <i>Bacillus</i> sp. Nnolim-K1 and the keratinase displayed potentials that demand industrial and biotechnological exploitations.
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