Journal Article

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

Rao, A. G. Appu, Vishwanatha, K. S, Singh, Sridevi Annapurna

2010

Overview

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°C, defatted soy flour addition of 4%, and fermentation time of 120 h, resulting in acid protease production of 8.64 × 10⁵ 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°C, 4.4% defatted soy flour addition, and fermentation time of 123 h to yield a maximum activity of 8.93 × 10⁵ U/g bran. Evaluation experiments, carried out to verify the predictions, reveal that A. oryzae produces 8.47 × 10⁵ 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].

• Publisher: Berlin/Heidelberg : Springer-Verlag,Oxford University Press,Springer-Verlag,Springer
• Subject: Aspergillus oryzae / Aspergillus oryzae - enzymology / Biochemistry / Bioinformatics / Biological and medical sciences / Biomedical and Life Sciences / biosynthesis / Biotechnology / Carbon / Carbon - metabolism / Culture Media / Enzymes / enzymology / Experiments / Fermentation / Food / Fundamental and applied biological sciences. Psychology / Fungi / Genetic Engineering / Hydrogen-Ion Concentration / Industrial Microbiology / Industrial Microbiology - methods / Inorganic Chemistry / Laboratories / Life Sciences / metabolism / methods / Methods. Procedures. Technologies / Microbial engineering. Fermentation and microbial culture technology / Microbiology / Models, Statistical / Moisture content / Nitrogen / Nitrogen - metabolism / Optimization / Original Paper / Oryza / Oryza - metabolism / Peptide Hydrolases / Peptide Hydrolases - biosynthesis / Prediction models / Proteases / proteinases / Proteins / Proteins - metabolism / solid state fermentation / soy flour / Studies / Substrate Specificity / Temperature / Time Factors / Triticum / Triticum - metabolism / Triticum aestivum / Variables / Wheat bran