Optimization of α‐Amylase Production on Raw Substrates in Haloalkaliphilic Actinobacteria, Nocardiopsis alba Kam‐13 by Statistical Approaches

Abstract

The use of low‐cost agricultural and food‐processing waste materials as substrates can reduce enzyme production costs and contribute to the sustainable management and valorization of waste. This work describes the optimization of α‐amylase production by the haloalkaliphilic actinobacterium Nocardiopsis alba Kam‐13, using potato peel extract as the primary substrate. The organism was isolated from the Kachhighadi Coast near Dwarka, Gujarat, India. The parameters for amylase production were optimized using the ‘One Variable At A Time (OVAT)’ approach. Amylase production was further optimized using the Plackett–Burman Design (PBD) and the Central Composite Design (CCD). Among the six parameters evaluated by PBD, incubation time, pH, and inoculum size had substantial beneficial effects and were further assessed by CCD with 20 experimental runs. The experimental responses corresponded well with the predicted values. Under the optimal conditions determined by response surface methodology (RSM), the production of α‐amylase was increased by nearly threefold to 582 U/mL. The results indicated that potato peel waste is a low‐cost, sustainable raw substrate for microbial growth and enzyme production. The study confirms the usefulness of agricultural and food waste materials in producing valuable enzymes by extremophilic actinobacteria.