Production of extracellular enzymes by a termite‐nest‐related Bacillus siamensisYC‐9 in solid‐state fermentation on agricultural by‐products

Abstract

AbstractA Bacillus siamensis YC‐9 strain was isolated from termite nest. The strain was used to produce several important industrial enzymes by utilizing different agricultural by‐products with solid‐state fermentation (SSF). It was observed that most of the substrates that were studied were strongly positively affected by alkaline treatment for the production of enzymes. The highest yields for protease, α‐amylase, and cellulase were 82.87, 42.81, and 1.54 IU g−1, achieved on alkaline‐treated corn pericarp, rice bran, and wheat bran respectively. However, untreated soybean meal was the best choice for the secretion of pectinases (66.65 IU g−1). In general, ultrasonic pretreatment was more effective than microwave treatment and it promoted the production of proteases on soybean meal, sunflower meal, and wheat bran. The findings of the present study will provide some theoretical basis for enzyme production in the future. © 2021 Society of Industrial Chemistry and John Wiley & Sons Ltd.