Production of enzymes by a new strain Streptomyces fluvissimus CKS7 using agricultural by-products

Abstract

In recent years, there have been an incresaing interest for reuse of agricultural by-products expecially in the field of microbial enzymes production. Theese kind of a agricultural waste are abundant, cheep and represent a good source of fermentable sugars and proteins which are necessary for microorganisms growth and enzymes production. Because of the stil high price of commercial enzymes, microbial enzymes produced by this way could reduce the cost of entire process. The potential of a novel bacterial strain Streptomyces fluvissimus CKS7, previously isolated from a soil, to produce industrially important enzymes was evaluated using selective agar plates. The strain was able to produce extracellular cellulase (CMC-ase and Avicelase), amylase, pectinase and xylanase. Different types of agricultural by-products (wheat bran, barley bran, ray bran, sunflower meal and soy meal) were used as substrates for CKS 7 growth and enzymes production. Solid state fermentation (SSF) was performed using these waste substrates. Among tested agricultural by-products, ray bran showed maximum enzymes production. During SSF on rye bran, the strain CKS7 produced several enzymes: cellulase (Avicelase and CMC-ase), amylase, pectinase and xylanase. An optimum solid: moisture ratio for maximum enzymes production was investigated. Maximum of CMC-ase 2.81 U/g, Avicelase 2.67 U/g, amylase 7.63 U/g, xylanase 6.84 U/g and pectinase 9.81 U/g activity was obtained at the sixt day of incubation with 10% of inoculum using rye bran as substrate. The results obtained in this study showed that agricultural by-products could be used as substrate for enzymes production.