Acid protease production by solid-state fermentation using Aspergillus oryzae MTCC 5341: optimization of process parameters

Abstract

Aspergillus oryzae MTCC 5341, when grown on wheat bran as substrate, produces several extracellular acid proteases. Production of the major acid protease (constituting 34% of the total) by solid-state fermentation is optimized. Optimum operating conditions obtained are determined as pH 5, temperature of incubation of 30 degrees C, defatted soy flour addition of 4%, and fermentation time of 120 h, resulting in acid protease production of 8.64 x 10(5) U/g bran. Response-surface methodology is used to generate a predictive model of the combined effects of independent variables such as, pH, temperature, defatted soy flour addition, and fermentation time. The statistical design indicates that all four independent variables have significant effects on acid protease production. Optimum factor levels are pH 5.4, incubation temperature of 31 degrees C, 4.4% defatted soy flour addition, and fermentation time of 123 h to yield a maximum activity of 8.93 x 10(5) U/g bran. Evaluation experiments, carried out to verify the predictions, reveal that A. oryzae produces 8.47 x 10(5) U/g bran, which corresponds to 94.8% of the predicted value. This is the highest acid protease activity reported so far, wherein the fungus produces four times higher activity than previously reported [J Bacteriol 130(1): 48-56, 1977].

Utilisation of common grain crops in Zimbabwe

“…Wheat bran can be used as an alternative to synthetic medium in fermentation processes (Pandey, 1992). Apart from that, wheat bran can be used as a supplement of nitrogen in medium for the production of enzymes like protease, amylase and glucoamylase (Vishwanatha et al, 2009). In addition, the compounds from wheat bran like lingocellulosic can be used to remove heavy metals like Cu II, Pb II and Cd II from industrial waste waters since the latter pose a health risk.…”

Application of Response Surface Methodology for Optimizing Process Parameters in the Production of Amylase by Aspergillus flavusNSH9 under Solid State Fermentation

“…It can be used to design the experiment and evaluate the interaction between variables and response. Inaddition, RSM is useful for optimization of the desirable response (Sharma et al 2007;Kar et al 2008;Shaktimay et al 2010;Vishwanatha, et al 2010). Therefore, the aim of this study was to evaluate the optimum fermentation process conditions for crude amylase production employing RSM by A. flavus NSH9 on sago hampas.…”

Optimization of Biobutanol Production from Poplar Wood Hydrolysate using a Mutant of Clostridium saccharobutylicum

“…These approaches have the advantage of reducing the number of experiments required. All of these approaches have been shown to work effectively in the bioprocess industry (Vishwanatha et al 2010).…”