Molecular characterization and growth optimization of halo-tolerant protease producing Bacillus Subtilis Strain BLK-1.5 isolated from salt mines of Karak, Pakistan.
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.
Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Pakistan. nawabali_1857@yahoo.com.
Nawab
N
Ali
Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Pakistan.
Nimat
N
Ullah
Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan.
Muhammad
M
Qasim
Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan.
Hazir
H
Rahman
Department of Zoology, Kohat University of Science and Technology, Kohat, Pakistan.
Shahid Niaz
SN
Khan
Department of Pharmacy, University of Malakand, Malakand, Pakistan.
Abdul
A
Sadiq
Department of Botany, Kohat University of Science and Technology, Kohat, Pakistan.
Muhammad
M
Adnan
D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D007218:Industrial Microbiology; D010447:Peptide Hydrolases / Q000235:genetics* / Q000378:metabolism; D055550:Protein Stability; D054712:Salinity; D055049:Salt Tolerance; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
D001426:Bacterial Proteins; D012987:Soil; D010447:Peptide Hydrolases
16S rRNA gene; Halo-tolerant; Proteolytic enzyme; Salt mines