Production of enzymes by a newly isolated Bacillus sp. TMF-1 in solid state fermentation on agricultural by-products: The evaluation of substrate pretreatment methods

Abstract Study on potential of different agro-industrial waste residues for supporting the growth of newly isolated Bacillus sp. TMF-1 strain under solid-state fermentation (SSF) was conducted aiming to produce several industrially valuable enzymes. Since the feasibility of the initial study was confirmed, further objectives included evaluation of several pretreatments of the studied agricultural by-products (soybean meal, sunflower meal, maize bran, maize pericarp, olive oil cake and wheat bran) on the microbial productivity as means of enhancing the yields of produced proteases, α-amylases, cellulases and pectinases. Among acid/alkaline treatment, ultrasound and microwave assisted methods, chemical treatments superiorly affected most of the studied substrates. Highest yields of produced proteases (50.5 IU g −1 ) and α-amylases (50.75 IU g −1 ) were achieved on alkaline treated corn pericarp. Alkaline treatment also promoted the secretion of cellulases on maize bran (1.19 IU g −1 ). Highest yield of pectinases was obtained on untreated soybean meal (64.90 IU g −1 ).