Optimization of alpha amylase production by solid-state fermentation of Bacillus sp.KR-8104 in a laboratory scale packed bed bioreactor

In this study the production of α-amylase by cultivation of Bacillus sp. KR-8104 on wheat bran under solid-state fermentation in a laboratory scale packed bed bioreactor was investigated. This strain is capable to produce a Ca independent α- amylase, which is active and stable at low pH values (4–6). The influence of airflow rate, initial substrate moisture and temperature on enzyme production was evaluated using response surface methodology based on Box-Behenken design. The experimental data was fitted to a polynomial model for the yield of enzyme, which revealedthe optimum levels of tested variables as follows: temperature 37 °C, initial moisture 72 % and airflow rate 0.15 L/min. The average α-amylase activity, 473.8 U/g dry fermented solids (in triplicate), under optimal conditions was obtained.

کلیدواژه ها:

α-amylase ، packed bed bioreactor ، solid-state fermentation ، response surface methodology ، Bacillus sp. KR- 8104