Production and biochemical characterization of an alkaline protease from Aspergillus oryzae CH93

• Published in: International journal of biological macromolecules Vol. 94; no. Pt B; pp. 827 - 835
• Main Authors: Salihi, Ahsan, Asoodeh, Ahmad, Aliabadian, Mansour
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-01-2017
• Subjects: 2-Propanol - chemistry; Alkaline protease; Aspergillus; Aspergillus oryzae - chemistry; Aspergillus oryzae - classification; Aspergillus oryzae - enzymology; Bacterial Proteins - biosynthesis; Bacterial Proteins - chemistry; Bacterial Proteins - isolation & purification; Caseins - chemistry; Characterization; Dimethyl Sulfoxide - chemistry; Edetic Acid - chemistry; Endopeptidases - biosynthesis; Endopeptidases - chemistry; Endopeptidases - isolation & purification; Enzyme kinetic; Enzyme Stability; Fungal Proteins - biosynthesis; Fungal Proteins - chemistry; Fungal Proteins - isolation & purification; Half-Life; Hydrogen-Ion Concentration; Mercaptoethanol - chemistry; Phylogeny; Protease Inhibitors - chemistry; Soil Microbiology; Substrate Specificity; Temperature; Characterization; Aspergillus; Enzyme kinetic; Alkaline protease
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2016.06.023

In this study, Aspergillus oryzae CH93 was isolated from soil sample and examined using molecular analysis. Following culture of A. oryzae CH93 under optimal enzyme production, a 47.5kDa extracellular protease was purified using ammonium sulfate precipitation and Q-Sepharose chromatography. The optimal pH 8 and temperature of 50°C obtained for the isolated protease. Sodium dodecyl sulfate (SDS), cetyltrimethyl ammonium bromide (CTAB), H2O2 decreased activity, while Triton X-100 and phenylmethanesulfonyl fluoride (PMSF) had no inhibitory effect on the enzyme activity; meanwhile, 2-mercaptoethanol and ethylenediaminetetraacetic acid (EDTA) declined the protease activity. Isoamyl alcohol and acetone (30%) enhanced activity whereas 2-propanol, isopropanol and dimethyl sulfoxide (DMSO) (30%) reduced protease activity. The enzyme exhibited a half-life of 100min at its optimum temperature. Among five substrates of bovine serum albumin (BSA), N-acetyl-l-tyrosine ethyl ester monohydrate (ATEE), casein, azocasein and gelatin results showed that casein is the best substrate with Vmax of 0.1411±0.004μg/min and Km of 2.432±0.266μg/ml. In conclusion, the extracted protease from A. oryzae CH93 as a fungal source possessed biochemical features which could be useful in some application usages.