Optimization of Pectinase Production from Bacillus velezensis Isolated from Agro-waste using Response Surface Methodology

Pectinases are important enzymes with significant applications in the industrial processing of juice clarification, oil and tea extraction, and paper manufacturing. The present study focused on obtaining bacteria capable of producing pectinase from agro-waste and optimising its production using statistical methods. Fifty-two bacterial isolates were initially obtained from rotting fruits and vegetable waste, of which 16 isolates showed pectin degradation on Yeast Extract Pectin (YEP) agar. Among these, isolate AW43 had the maximum zone of hydrolysis (23.3 mm) and enzymatic activity (150.019 U/mL), which was identified as Bacillus velezensis using 16S rRNA gene sequencing (PCR-based identification). Optimization of pectinase production was initially carried out using a Plackett-Burman design, where out of eleven parameters, pectin, yeast extract, glucose, pH, and temperature were identified as those that positively modulated pectinase production. Utilizing the Box-Behnken design, the research identified that the optimal conditions for pectinase production were achieved with a pectin concentration of 5.5 g/L, yeast extract at 10 g/L, glucose at 1.0 g/L, a pH level of 7.0, and an incubation temperature of 30 °C. These results indicate that B. velezensis is a promising microbe for the production and purification of commercially viable pectinase.