Production of extracellular enzymes by two Pleurotus species using banana pseudostem biomass

Abstract

AbstractThe degradation of lignocellulosic biomass of banana pseudoste was investigated during solid state fermentation (SSF) by P. ostreatus and P. sajor‐caju. Both organisms proved to be efficient degraders of banana pseudostem biomass. P.ostreatus degraded hemicellulose (40% of dry weight, d.w.) better than cellulose (17.5% of d.w.) and lignin (10% of d.w.). P. sajor‐caju also degraded hemicellulose (31% of d.w.) better than cellulose (12.4% of d.w.) and lignin (6% of d.w.). In both cases, a preferential removal of hemicellulose during the initial growth period and a delayed degradation of lignin were observed. The kinetics of cellulolytic, hemicellulolytic and lignolytic enzyme production in liquid culture were also examined. The activities of CMCase and β‐glucosidase were highest at 16 days of growth and avicelase activity was at its maximum after 24 days (CMCase ‐ 1.1 IU/ml, β‐glucosidase ‐ 0.09 IU/ml in the case of P. ostreatus; CMCase ‐ 1.0 IU/ml, β‐glucosidase ‐ 0.087 ‐ IU/ml in the case of P. sajor‐caju.). Xylanase and laccase activity reached their maximum after day 16 and day 24 of incubation, respectively. (Xylanase ‐ 1.1 IU/ml and laccase 3.0 IU/ml in the case of P. ostreatus; xylanase ‐ 1.0 IU/ml and laccase ‐ 3.6 IU/ml in the case of P. sajor‐caju.). The efficient degrading capacity of test fungi demonstrated their potential use in the conversion of banana pseudostem biomass into mycelial protein‐rich fermented animal feed.