Statistical optimization of a novel extracellular alkaline and thermostable amylase production from thermophilic Actinomadura keratinilytica sp. Cpt29 and its potential application in detergent industry

Abstract

Amylolytic enzymes are biocatalysts, which are widely used in several industrial sectors. The present study was carried out to investigate amylase production by a thermophilic actinobacteria strain Actinomadura keratinilytica Cpt29. Initially, optimization of nutritional and environmental factors was performed using the One Variable at Time (OVAT) approach and Plackett–Burman design. Further, the optimum level of each factor was determined using Box–Behnken design (BBD). The different investigations employed showed that corn starch and tryptone were found to be the best carbon and nitrogen sources, respectively. Corn starch, tryptone, and pH seem to be the most influential variables for amylase production. Enhancement of 1.5-fold in the catalytic activity was reached after optimization. The obtained enzyme was characterized. Optimal enzyme activity was recorded with an alkaline pH of 8.0 at 70 °C and significantly enhanced by Ca 2+ and Mg 2+ . Good stability was retained over a broad range of pH and temperature. Also, the obtained amylase showed strong tolerance to the commercial detergents tested and excellent cleaning efficiency, which makes this enzyme an interesting new additive for detergent formulations. • Actinomadura keratinilytica Cpt29 thermophilic actinomycete used for amylase production. • Corn starch and tryptone are the best carbon and nitrogen sources according to the One-factor-at-a-time optimization. • Enhancements of 1.5 fold in amylase production with the Response Surface methodology optimization. • The amylase from Actinomadura keratinilytica Cpt29 exhibited promising properties for biotechnological applications.