Production of Extracellular Alkaline Serine Protease from Pediococcus acidilactici NCDC 252: Isolation, Purification, Physicochemical and Catalytic Characterization

Proteases are the most important industrial enzymes capable of hydrolyzing proteins into small peptides and amino acids and used commercially in food, textile and pharmaceutical industries. An alkaline serine protease from Pediococcus acidilactici NCDC 252 was purified using a simple two step purification procedure i.e. ammonium sulphate precipitation and gel filtration chromatography with purification fold of 5.9, a yield and specific activity of 11.8% and 23.3 U mg/ml respectively. Purified enzyme worked optimally at pH 8.5 and 37 degrees C. The enzyme was stable in the pH range of 6.5-9.5 and up to 50 degrees C. The K-m for BAPNA was 38 mu M and V-max was 10.6 U/mg. Purified enzyme exhibited highest hydrolyzing activity for BAPNA. Inhibition of purified enzyme by soybean trypsin inhibitor, benzamide and mu-ME suggested the enzyme to be alkaline serine protease with involvement of cysteine residues either in binding or regulation. In-silico characterization of alkaline serine protease revealed the presence of Ser, His and Asp residues at its catalytic site. This shows the resemblance of alkaline protease under study with other studied serine proteases. [GRAPHICS] .

Automated summary

An alkaline serine protease from Pediococcus acidilactici NCDC 252 was purified and characterized, exhibiting high hydrolyzing activity and stability. Its in-silico characterization revealed similarity with other serine proteases, indicating potential industrial applications.