Production, Immobilization and Evaluation of Xylanase's Efficacy from Streptomyces Sp. NRC-EAK-H26 Grown on Lignocellulosic Waste

Abstract

The main objective of this research is to produce and immobilize xylanase enzyme from Streptomyces sp. isolated from Egyptian soil. We managed to isolate and identify Streptomyces sp. NRC-EAK-H26 from Egyptian soil of the Nile delta via 16S rRNA sequencing method that was further selected to produce xylanase enzyme using agriculture wastes. The highest xylanase production, 6.85 U/mL, was obtained when wheat bran was used as a sole carbon source and the medium was supplemented with 0.2% potassium nitrate. The optimal xylanase production was encountered when the media were incubated for five days at 35°C and pH 6.5. The enzyme was successfully immobilized using sodium alginate/k-carrageenan beads, achieving an immobilization efficiency of 86.9% at optimum pH shifted from pH 7 to pH 8 and optimum temperature increased from 50°C to 60°C. Interestingly, the immobilized xylanase enzyme possessed 81% of its initial hydrolytic activity after eight cycles of use, indicating excellent reusability. Thermal and pH stability of both free and immobilized xylanase were studied. The immobilized xylanase retained 55.5% of its activity at 80°C after 30 min. and was able to keep up to 33.2% of its initial activity at pH 8 after 2 h. The enzyme's stability and activity suggest its potential for producing xylo-oligosaccharides from agricultural wastes like wheat bran. The ability of the immobilized xylanase enzyme to keep hydrolytic activity over multiple uses is particularly valuable for industrial applications, where cost-effectiveness and efficiency are crucial.