Isolation and identification of halophilic bacteria associated with rhizospheric soil from the Arabian coast of Dakshina Kannada, Karnataka, India
Volume 65 Issue 1
B. K. Paramashree Deepa and M. N. Siddaraju
doi:10.6024/jmbai.2023.65.1.2388-02
Abstract
Halophiles are excellent sources of numerous potential biomolecules, such as stable enzymes (halozymes), compatible solutes, and novel exopolymers with industrial, medicinal, bioremediation, plant growth-promoting applications etc. In this study, we have screened for rhizospheric bacteria from the Arabian coast of Dakshina Kannada, Karnataka, India and isolated over 90 halotolerant bacteria, which grow up to 0-8% of NaCl (w/v). The comparative partial 16S rRNA sequence analysis and phenotypic characteristics showed that the isolates belong to the genera Luteimonas, Ensifer, Bacillus, Mesobacillus, Cellulosimicrobium, Rhizobium, Citrobacter and Microvirga. The growth of the isolates was up to pH 7-11, 30-40°C temperature and 2% NaCl (w/v) and for some, it was the same up to 45°C, 5% and 8% NaCl (w/v) as reported. The isolates produced various enzymes such as catalase, gelatinase, urease, and oxidase. All the isolates produced enzymes up to pH 11, 40 °C temperature and 2% NaCl (w/v). Isolates such as Ensifer sojae strain UCM-2, Cellulosimicrobium funkei strain UCM4 and Rhizobium pusense strain UCM-5 produce enzymes up to 5% NaCl and isolate Mesobacillus subterraneus strain UCM-3, Bacillus subtilis strain UCM6, Citrobacter freundii strain UCM7 and Bacillus cereus strain UCM8 produces enzymes at 45°C and 8% NaCl (w/v). To our knowledge, this is the first study on the microbial diversity of the rhizospheric-halophilic bacterial community producing industrially important enzymes in coastal regions of the Arabian sea coast of Dakshina Kannada, Karnataka, India.
