Screening of bacterial isolates for protease production with special reference to molecular identification of highly producer strains

Mohamed, Alaa Mostafa; Sayed, Ahmed; A. Abd El-Aziz, Fatma; Abd-Elmonsef Mahmoud, Ghada

doi:10.21608/jamb.2023.219174.1007

Screening of bacterial isolates for protease production with special reference to molecular identification of highly producer strains

Document Type : Original Article

Authors

¹ Molecular Biology Department, Molecular Biology Research& Studies Institute, Assiut University, Egypt.

² Chemistry Department, Faculty of Science, Assiut University, Egypt.

³ Zoology Department, Faculty of Science, Assiut University, Egypt.

⁴ Botany & Microbiology Department, Faculty of Science, Assiut University, Egypt.

10.21608/jamb.2023.219174.1007

Abstract

Proteases play a critical role in many industrial applications. The most important advantage of microbial proteases is that they can tolerate harsh industrial conditions. In this study, 17 bacterial strains were isolated from different milk products. The bacterial isolates were screened for their capabilities to produce protease enzyme in normal and alkaline conditions with pH values 7.4 and 9.4 on skimmed milk and casine agar plate respectively at 30°C. The enzyme index (EI) for protease was measured for the highly protease producer strains in normal and alkaline media (1.6±0.02,1.4±0.1,0.9±0.05 in nomal medium but 2.2±0.04, 2.5±0.06, 1.7±0.04 in alkaline medium for ASU2,ASU1,Sm-26 respectively). Biochemical tests were performed for the highly protease producer isolates. Genetically identification of bacteria was carried out through 16S rRNA gene sequencing. The current results indicated that the highest protease-producing bacterial strains were Bacillus subtilisAUS2 , Bacillus tequilensis AUS1, and Serratia marcescens. This study emphasized the necessity of utilizing microorganisms as promising enzyme producers employed in several industrial applications.

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