Amylase enzyme from Bacillus subtilis S8-18: a potential desizing agent from the marine environment

The present study is aimed at developing an economical medium for the production of α-amylase from Bacillus subtilis S8-18, a marine sediment isolate from Palk Bay, with various agricultural by-products that are cheap and rich in starch. These products include wheat bran, wheat husk, rice bran, rice husk, and potato peel and are used to replace soluble starch present in the Luria Bertani (LB) broth (synthetic medium). The rice husk was found to be the best to influence enzyme production significantly (61,186 IU mL⁻¹) when compared with the yield of 30,026 IU mL⁻¹ obtained by commercial starch. Hence, LB broth containing rice husk was considered an economical medium. In addition, the effect of various nutritional and physiological factors on enzyme production was also investigated. Furthermore, the desizing efficiency of α-amylases produced by synthetic and economical media was evaluated through various assays like reducing sugar estimation, weight loss assay, drop absorbency assay, scanning electron microscopy, and Fourier transform infrared analyses. In addition, a commercial α-amylase from B. subtilis was also used in desizing analyses for comparative purposes. It revealed that the α-amylase from the economical medium was as effective in desizing the cotton fabrics as that of the commercial enzyme and much superior to the enzyme produced through the synthetic medium.