Effect of variations in growth parameters on cellulase activity of Trichoderma viride NSPR006 cultured on different wood-dusts

Abstract

Aims: The biotechnology research into agro wastes has been driven by the need to screen organisms for hyperproduction of novel extracellular enzymes in which cellulase plays a significant role. Therefore, the aim of the study was to pre-screen selected fungal strains and optimize cultural conditions for cellulase production by Trichoderma viride NSPR006 cultured on pretreated sawdust as lignocellulosic substrate. Methodology and results: The selected fungal isolates namely Trichoderma viride NSPR006, Botrydiplodia NSPR007 and Acremonium butyri NSPR06B obtained from the culture collection of the Nigerian Stored Products Research Institute Ilorin, Kwara State, Nigeria were screened for the production of cellulase in mineral salt medium in which carboxymethylcellulose (CMC) had been incorporated as the sole carbon source. All the tested fungal isolates produced cellulase with differences in the amount of enzyme production. Of all the selected fungal isolates screened, Trichoderma viride NSPR006 was found to yield highest cellulase activity compared to the other isolates. Among tested carbon sources, Pachyslasma tessmani wood dust at 3% level proved to the best for cellulase production. Of the entire tested organic nitrogen sources, locust beans were observed to yield maximum cellulase activity (0.194 µmol/min/mL). The optimum temperature, incubation time and pH for maximum cellulase production were 28 °C, 72 h and 6.5, respectively. Conclusion, significance and impact of study: Outcome of this study shows the effectiveness of pre-treatment of wood dust as low cost system for hyper-production of cellulase for industrial application. Also, the work revealed the use of pretreated wood dust as substitute to commercial substrate known to be expensive in cellulase production.