Utilization of agroindustrial by-products as substrate in endoglucanase production by streptomyces diastaticus pa-01 under submerged fermentation

Abstract

Endoglucanase production under submerged fermentation was studied using sugarcane bagasse (SCB) and oat bran (OB) as carbon source and corn steep liquor (CSL) as nitrogen source, in different concentrations using factorial design. Streptomyces diastaticus PA-01, isolated from a soil cave in Brazil, was selected as cellulolytic strain. The results after experimental validation showed that a medium containing 2.4% (w/v) SCB and 1.3% (w/v) CSL led to the highest production, 1,180.3 U.L-1 of endoglucanase, after the 5th-day. A good level of endoglucanase (1,039.3 U.L-1) was obtained after the 4th-day when 2.0% (w/v) OB and 1.65% (w/v) CSL were used. The pH and temperature profiles showed thermoacidophilic endoglucanase activity, with 70% of maximum activity at 50ºC, after 4 hours of pre-incubation. This is the first report on endoglucanase production by S. diastaticus PA-01 in the presence of SCB and OB. The strong positive effects of some metal ions (Zn2+, Mn2+ and Ba2+) on endoglucanase activity when this strain was grown on OB is an interesting biochemical characteristic for future biotechnological applications.