Enhancement of Indigenous Fungal Cellulase Production by Gamma Rays

Abstract

Abstract The increasing demand for cellulases causes the need for a high cellulase-producing microbe. Mutagenesis is an efficient way to produce a high-titer cellulase-producing strain. Mutagenesis using gamma rays irradiation has the advantage that it can cause a double strand break of DNA. Repair of double-strand break tends to has an error-prone repair that leads to the alteration of DNA sequence. The aim of this study was to screen high cellulase-producing indigenous fungal mutants produced by mutagenesis. Trichoderma sp. PK1J2 was subjected to gamma irradiation at 300 Gy. The mutants produced were screened using a plate medium containing cellulose as a sole carbon source. After staining with congo red, colonies with wider clear zones were grown in a liquid medium for four days, and the cellulase activities were analyzed. Mutant M8 produces endoglucanase, FPase, and β-glucosidase at 0.46 U/ml, 0.18 U/ml, and 1.10 U/ml, respectively, which were 90%, 50%, and 30% higher than those of the parental strain.