Evaluation of Ca-independent alpha-amylase production by Bacillus sp. KR-8104 in submerged and solid state fermentation systems

ABSTRACT

This study investigates the production of crude Caindependent and low pH active alpha-amylase by Bacillus sp. KR-8104 in submerged fermentation [SmF] and solid-state fermentation [SSF] systems. Different parameters were evaluated in each system using "one factor at a time" approach to improve the production of enzyme. The results showed that in the SmF the maximum enzyme production was achieved in culture medium that contained dextrin as a carbon source, as well as yeast extract and meat extract as nitrogen sources incubated at 37§C and 180 rpm for 48 h. While SSF of Bacillus sp. KR-8104 using wheat bran [WB] as a substrate showed that using tap water or distilled water as a moisturizing agent, a substrate-water ratio of 11.5 [w/v] and incubation at 37§C for 48 h gave the maximum alpha-amylase production. From different extraction medium examined in this study 0.1% [v/v] aqueous mixture of Tween 20 and distilled water illustrated maximum results [100 U/g]