Molecular characterization and growth optimization of halo-tolerant protease producing Bacillus Subtilis Strain BLK-1.5 isolated from salt mines of Karak, Pakistan

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• 作者：Nawab Ali ; Nimat Ullah ; Muhammad Qasim ; Hazir Rahman ; Shahid Niaz Khan…
• 刊名：Extremophiles
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：20
• 期：4
• 页码：395-402
• 全文大小：989 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Microbiology
  Biotechnology
  Ecology
  
• 出版者：Springer Japan
• ISSN：1433-4909
• 卷排序：20

文摘

Microbial proteolytic enzyme is one of the most important industrial enzymes that hydrolyze proteins. The applications of proteases under harsh industrial conditions like alkalinity, salinity, and temperature make them inactive and unstable. This suggests need for search for novel microbial sources for protease production having diverse properties. For this purpose, 54 bacterial strains were isolated from different salt mines of Karak, Pakistan and were investigated for their proteolytic activity on skim milk agar plates. The strain which showed maximum protease activity was characterized by 16S rRNA gene sequence analysis. Furthermore, growth and protease production was optimized for the characterized bacteria under different physical factors, i.e., pH, temperature and salinity. The isolate BLK-1.5 exhibited strong protease production and was identified as Bacillus subtilis based on biochemical characteristics and 16S rRNA gene sequence analysis. Maximum production of protease was recorded at pH 10, 37 °C and 7 % (w/v) NaCl. Molecular weight of proteases was estimated 38 kDa and its optimum activity was observed at pH 10, 50 °C and 2 % (w/v) NaCl. In conclusion, the protease produced by halo-tolerant Bacillus subtilis strain BLK-1.5 has diverse characteristics and could be useful in various industrial applications.KeywordsProteolytic enzymeSalt mines16S rRNA geneHalo-tolerant