Optimization and validation of keratinase production by Bacillus aerius NSMk2 in a stirred tank reactor using response surface methodology

Abstract Keratinase is a robust enzyme that produced in the presence of keratin substrates. This has been recognized for its applications waste management, leather and detergent industries. Our group isolated potential keratinase producing strain Bacillus aerius NSMk2 from poultry dump soil, hide dehairing stain removal have studied. Considering commercial applicability keratinase, present study reports production stirred tank reactor (5 l). Central composite rotatable design response surface methodology (RSM) was employed to effect most influencing process variables, i.e., aeration (0.5–1.5 vvm), agitation (150–350 rpm) incubation period (24–48 h) on production. The quadratic model predicted 15 experimental runs, influence independent variables their interaction were interpreted using analysis variance (ANOVA) t -test statistics. Coefficient determination ( R 2 ) value close 1 Fisher F -value 3743.77 showed good fit data second-order polynomial equation. A reasonable agreement between values accuracy deduced model. Applying desirability function, rate 1.0 vvm, 276.88 rpm 33.68 h supported maximum (318.38 U/ml). Confirmatory experiments performed evaluate function. Maximum activity 318.11 U/ml U/ml) validates provides useful guidelines large-scale can be used various applications. Article highlights optimized by RSM. aeration, significant increase observed at vvm after h.