Screening and production of mannanase by Bacillus strains isolated from fermented food condiments

Abstract

Bacillus strains isolated from ‘Iru’ and ‘Ugba’ was screened for mannanase production and production condition was optimized. Twenty two Bacillus strains isolated were Bacillus subtilis IE, Bacillus pumilus S5, Bacillus licheniformis S4, Bacillus cereus U9, Bacillus megaterium U1 and Bacillus coagulans U3. Bacillus subtilis IE had the highest frequency of occurrence (31.82%). After screening six strains were selected for mannanase production under optimized condition. pH 5.0 was optimum for mannanase production by B. subtilis IE (0.1600 U/ml) and B. pumilus S5 (0.1989 U/ml). Optimum growth was at pH 3 and 40oC for all the isolates except B. subtilis IE. B. subtilis IE (0.0700U/ml) and B. megaterium UI (1.561) had the highest production and growth. 30 and 36 hours incubation time was optimum for mannanase production and growth. B. subtilis IE (0.203a U/ml) and B. megaterium UI (0.800 a) had the highest. Agitation condition, fructose and glucose induced optimum mannanase production and growth, it ranged from 0.042 – 0.1179 U/ml and 0.074 – 0.611 in which B. subtilis IE and B. licheniformis S4 had the highest. Urea and yeast extract was the best nitrogen source for mannanase production and growth by B. subtilis IE (0.198 U/ml) and B. megaterium UI (1.561).