SOLID STATE FERMENTATION MEDIA OPTIMIZATION FOR PRODUCTION OF α-Amylase BY Aspergillus sydowii IMI 502692

Aspergillus sydowii IMI 502692 isolated from cassava processing agro-enterprise waste dump site was cultivated by Solid-State Fermentation of cassava root fibre (5 g) buffered with basal medium (20 ml) made up of % (w/v): CaCl2.2H2O, 0.05 g, (NH4)2SO4, l g; KH2PO4, 0.3 g; MgSO4.7H2O; 0.05 g. The culture condition for α-amylase production by A. sydowii IMI 502692 was optimized. Organic nitrogen (cow blood meal) gave maximum α-amylase yield (1.462 Uml-1) while the effect of varying concentration of cow blood meal shows that 0.3% (w/v) was optimum for α-amylase production with 1.602 Uml-1 Tween 20 0.5% (v/v) induced amylase production most with the activity of 1.626 Uml-1. The initial based medium pH of 6.0 gave maximum enhancement of α-amylase activity (2.050 Uml-1). Sulphate salts of Ca2+ and Mn2+ 5 mM induced α-amylase production while that of Sr2+, Fe2+, Zn2+ and N12+ repressed the enzyme production. α-Amylase production kinetics in solid-state fermentation of the buffered cassava root fibre revealed an optimum α-amylase activity (1.910 Uml-1) occurring at day 3 with a corresponding culture pH of 3.645 Biomass accumulation rose from day 1 (0.010 g) and progressed through the period of fermentation to day 5 (0.303 g).