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

Abstract

This study investigates the production of crude Ca-independent and low pH active α-amylase by Bacillus<br />sp. KR-8104 in submerged fermentation (SmF) and solid-state fermentation (SSF) systems. Different<br />parameters were evaluated in each system using “one factor at a time" approach to improve the production of<br />enzyme. The results showed that in the SmF the maximum enzyme production was achieved in culture<br />medium that contained dextrin as a carbon source, as well as yeast extract and meat extract as nitrogen<br />sources incubated at 37ºC and 180 rpm for 48 h. While SSF of Bacillus sp. KR-8104 using wheat bran (WB)<br />as a substrate showed that using tap water or distilled water as a moisturizing agent, a substrate-water ratio<br />of 1:1.5 (w/v) and incubation at 37ºC for 48 h gave the maximum α-amylase production. From different<br />extraction medium examined in this study 0.1% (v/v) aqueous mixture of Tween 20 and distilled water illustrated maximum results (~100 U/g).<br /><br />