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Optimization and characterization of cold-active endoglucanase produced by Aspergillus terreus strain AKM-F3 grown on sugarcane bagasse

The psychrotolerant microfungus Aspergillus terreus strain AKM-F3 (GenBank Accession No. KF417464) was investigated for the production of cold-active endoglucanase using sugarcane bagasse. The effects of different process parameters were studied for hyperproduction. | Turkish Journal of Biology http://journals.tubitak.gov.tr/biology/ Research Article Turk J Biol (2015) 39: 175-185 © TÜBİTAK doi:10.3906/biy-1408-22 Optimization and characterization of cold-active endoglucanase produced by Aspergillus terreus strain AKM-F3 grown on sugarcane bagasse Abhas Kumar MAHARANA*, Pratima RAY Department of Microbiology, Centre for Post Graduate Studies, Orissa University of Agriculture and Technology, Surya Nagar, Bhubaneswar, Odisha, India Received: 08.08.2014 Accepted: 12.09.2014 Published Online: 02.01.2015 Printed: 30.01.2015 Abstract: The psychrotolerant microfungus Aspergillus terreus strain AKM-F3 (GenBank Accession No. KF417464) was investigated for the production of cold-active endoglucanase using sugarcane bagasse. The effects of different process parameters were studied for hyperproduction. Optimum production was found at 15 °C with an initial pH of 5.0 at 120 h. For enzyme production, 1 mM ZnCl2, 0.01% aspartate, 2% lactose, and 3% NaNO3 were regarded as potent inducers. The final production gave an activity 3.764-fold higher than the unoptimized conditions. The molecular weight of purified endoglucanase was 55 kDa, showing a 3.464-fold purification increase with a 23.925% yield having 75.279 U/mg of specific activity. The Km and Vmax values of the purified enzyme were found to be 0.37 mg/mL and 24.63 U/mg, respectively. The enzyme was more active at 35 °C and pH 4.0, whereas more stability was observed at 0 °C and pH 7.0. Ca2+, Mn2+, and all tested organic solvents were found to be activators of endoglucanase. EDTA had very low effect, whereas the most active inhibitor was sodium deoxycholate. The present study successfully produced a cold-active endoglucanase with novel properties that can be used for the degradation of cellulosic wastes in cold regions and the economically sound removal of unwanted extra microfibrils from cotton. Key words: Aspergillus terreus, cold-active, cold-temperature fermentation, .