Production of cellulase by Mucor ramanniacus using submerged fermentation and its applications in biodegradation of agro-industrial waste

Abstract

This study was undertaken to isolate and identify a novel cellulase-producing strain from a waste site (7°28’11’’N 4°31’24’’E), optimise the growth conditions, partially purify and biochemically characterise the enzyme. The potentials of the puri􀂦ed cellulase to hydrolyse the lignocellulosic component of some agroindustrial wastes (e.g. orange peels etc.) was also investigated. The best cellulase-producing fungus was identi􀂦ed as Mucor ramanniacus and the optimum conditions for cellulase production were pH (4.5), inoculum size (12 mm), carbon and nitrogen sources were carboxymethyl cellulose and sodium nitrate respectively resulting in a speci􀂦c activity of 1423 Units/mg protein. A puri􀂦cation fold of 1.56 and 45.37 % yield were obtained after puri􀂦cation. The optimum pH and temperature were at 9.0 and 40°C respectively. The kinetic parameters were 0.63 ± 0.495 mg/ml, 20.21 ± 11.28 U/ml, 1001.4s− 1 for Km and Vmax and kcat respectively. Na+, K+, Ca+, Cysteine, β- mercaptoethanol and SDS were activators while Tween 80, Triton X-100 EDTA, Hg2+ and Ba2+ inhibited the enzyme. M. ramanniacus cellulase hydrolysed all agro-industrial wastes used. The partially puri􀂦ed M. ramanniacus cellulase showed great potential in biodegradation of various lignocellulosic substrates and the biochemical characteristics exhibited makes it suitable in industrial applications.