Utilization of Agricultural By-Products for Alpha-Amylase Production under Solid State Fermentation by Bacillus Subtilis
The production of alpha-amylase by Bacillus subtilis was investigated under different cultivation conditions on two different solid substrates as the support, i.e. oil palm empty fruit bunch (OPEFB) and rice straw fibers using solid state fermentation (SSF) process. Both solid substrates were first pre-treated using NaOH to remove lignin and silica and to break down the hemicellulose structures. The influences of incubation time, incubation temperature and the additional carbon and nitrogen sources on the production of alpha-amylase by B. subtilis were investigated. After 48 h of incubation, the highest enzyme activities were obtained at 39.9 U/g and 23.5 U/g for rice straw and OPEFB fibers, respectively. The optimum temperature for alpha-amylase production was observed at 45°C for the OPEFB fibers and 55°C for the rice straw fibers. Among the defined carbohydrates, the addition of glucose (0.02 g/g dry substrate) has significantly improved the production of alpha-amylase. Similar effect was observed when yeast extract (0.01 g/g dry substrate) was supplemented as the additional nitrogen source. Rice straw fibers appeared to be the best solid substrate in producing alpha-amylase (276 U/g) in SSF under these optimum cultivation conditions.
How to Cite
Authors who publish with Engineering Journal agree to transfer all copyright rights in and to the above work to the Engineering Journal (EJ)'s Editorial Board so that EJ's Editorial Board shall have the right to publish the work for nonprofit use in any media or form. In return, authors retain: (1) all proprietary rights other than copyright; (2) re-use of all or part of the above paper in their other work; (3) right to reproduce or authorize others to reproduce the above paper for authors' personal use or for company use if the source and EJ's copyright notice is indicated, and if the reproduction is not made for the purpose of sale.