Isolation and Biochemical Properties of Extremophilic Keratinase from Bacillus cereus FC1365

Keratinases secreted by microorganisms belong to proteolytic enzymes with unique characteristics to efficiently degrade tough, fibrous, and hydrolysis resistant keratin proteins. In this study, the biochemical characterization of a highly thermoactive and alkalophilic keratinase enzyme (FCnase) was reported that was isolated from the soil samples procured from a Bengaluru-based poultry dump yard, India. The screened isolate was identified as Bacillus cereus FC1365 (# MN712509—accession number) by 16S rRNA gene sequencing . FCnase production was carried out in minimal salt media supplemented with feather meal, and partial purification of the extracellularly secreted enzyme was achieved by acetone precipitation method. 3.4-fold purification of the enzyme was attained with a maximum activity of 21.4 U/ml. The enzyme was optimally active at pH 10 and 70 ℃. K m and V max of the enzyme were 0.396 mg/ml and 2.86 U/ml, respectively. SDS-PAGE and Zymogram confirmed the molecular weight of the FCnase as 63 kDa. Metal ions like Ca 2+ and Mg 2+ enhanced the enzyme activity while the ethylenediaminetetraacetic acid inhibited it, proving it to be a metalloprotease. Efficient feather degradation was demonstrated by the isolated robust enzyme making it suitable for feather waste management and other industrial applications.