Document Type : Research Paper
Department of Food Science and Engineering, Faculty of Agricultural Engineering and Technology, University of Tehran, P.O. Box 4111, Karaj, I.R. Iran.
Department of Microbial Biotechnology and Biosafety, Agricultural Biotechnology Research Institute of Iran (ABRII), P.O. Box 31535-1897, Karaj, I.R. Iran.
Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, P.O. Box 14115-143, Tehran, I.R. Iran.
This study investigates the production of crude Ca-independent and low pH active α-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 37ºC 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 1:1.5 (w/v) and incubation at 37ºC for 48 h gave the maximum α-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).