Extracellular Acid Exoglucanase from Halophilic Fungi : Strategies for Production and Characterization

Research on cellulase has progressed very rapidly over the last five decades. Now a day, majority of commercial cellulases are being produced by fungi such as, Trichoderma. However halophilic fungi can be a valuable resource for the same. The present study deals with the extracellular cellulases from Halophilic fungi isolated from the Great Rann of Kutch, India. The isolates, designated as B10-1 and D10-2 were having mycelia structure similar to Aspergillus spp. and grew optimally with 10% w/v NaCl. B10-1 and D10-2 grew optimally at pH 6 with slow growth at higher pH. In case of B10-1 and D10-2, the optimum cellulose concentration for cellulase production was 0.5% w/v and 1.5% w/v respectively. Both the isolates produced cellulase optimally at 10% NaCl and pH 6. B10-1 and D10-2 exoglucanase were purified to 10.98 fold and 4.23 fold respectively by (NH4)2SO4 fractionation. Partially purified extracellular exoglucanase was characterized further. The enzymes displayed optimum activity at 60C beyond which the activity gradually declined. The enzymes were active at 60C for more than an hour. The enzymes of both the isolates withstand even at 70C for more than half an hour.