Evaluation of extracellular cellulolytic potential of selected natural strains of a novel fungus Sordaria fimicola isolated from evolutionary canyon under submerged fermentation

Abstract

Industrial biotechnology has a great emerging demand and sustainable expansion for mankind to utilize a variety of biodegradable material for the production of various alternative energy resources such as biogas and bioethanol. Researchers are interested in exploitation of novel fungal strains for the production of extracellular cellulase from the last few decades. This study was designed to assess the extracellular cellulase production potential of novel fungal strains of Sordaria fimicola first isolated from the evolution canyon, three located on South facing slope with xeric (S1, S2, S3) and other three on North facing slope with mesic (N5, N6, N7) environmental conditions. Based on initial and secondary screening two hyper producer strains from each slope were selected. The best activity for S2 was 3.125 U/ml and N6 exhibited 2.829 U/mL under optimized conditions of 14 d of incubation at 30 ^oC, pH 6.0, 1 mL inoculum and with 2% substrate (carboxy-methyl cellulose) concentration. Among the tested carbon and nitrogen sources, glucose proved to be best for both strains with S2 exhibiting maximum activity. Peptone and beef extract proved to be the best nitrogen sources for S2 and N6 respectively. The cellulase after characterization for temperature and pH showed slightly thermophilic nature. The cellulase was partial purification the highest cellulase activities as surviving in more xeric conditions which contribute more resistive and productive features in those microorganisms living in the harsh environment.