Journal of Microbial & Biochemical Technology

Multiple forms of extracellular endoglucanase from Aspergillus sydowii IMI 502692

12^th World Congress on Biotechnology and Microbiology

June 28-29, 2018 | Amsterdam, Netherlands

Adegoke Sunday Adetunji and Odibo F J C

Kogi State University, Nigeria
Nnamdi Azikiwe University, Nigeria

Posters & Accepted Abstracts: J Microb Biochem Technol

Abstract:

Time-course of endoglucanase (EC 3.2.1.4) production by Aspergillus sydowii IMI 502692 in solid substrate fermentation of cassava root fibre shows that the enzyme was maximally produced on 4th day with culture pH of 4.937. Endoglucanase was partially purified from Aspergillus sydowii IMI 502592 cell free culture extract. Enzyme activities were routinely assayed using low viscosity carboxymethyl cellulose as a substrate. The enzyme was concentrated by dialysis against 5 M sucrose solution and isolated with ion exchange chromatography on Carboxymethyl Sepharose and gel filtration chromatography on Biogel P 4. The elution profile revealed two protein peaks for endoglucanase I and endoglucanase II showing cellulolytic activities. Endoglucanase I of A. sydowii IMI 502692 was purified 2.44 fold to give 0.93% yield and a specific activity of 112.34 Umg-1 protein. Endoglucanase II was purified 1.83 fold to give 1.14% yield and a specific activity of 57.35 Umg-1 protein. Endoglucanase I was characterized by demonstration of optimum activity at 40oC and pH 3.0 and retention of 65% activity at 70oC (1h). Endoglucanase II had optimum activity at 50oC and pH 7.0 and retained 69% activity at 40oC (1h). Endoglucanase I had a broad pH stability range and temperature activity range of 3 to 6 and 30oC to 80oC, respectively unlike endoglucanase II with single peak of pH stability and temperature activity at 6.0 and 50oC, respectively. Mn2+ activated endoglucanase I activity most while Fe2+ activated endoglucanase II activity most. Both enzymes activities were inhibited by Cu2+ and Ni2+ in addition, Ca2+ also inhibited endoglucanase II.