Isolation and 16s rRNA analysis of thermophilic and halophilic bacteria isolated from Izmir Dikili (Bademli) hot spring

In recent years, studies on extreme biodiversity have focused on the use of biotechnologically important microorganisms. In biotechnological properties, microorganisms resistant to extreme conditions such as high temperature, high salt, acid and pressure and their bioproducts are preferred. Hot springs are one of the natural habitats for especially halophilic and thermophilic extremophile microorganisms. The aim of this study is to isolate and characterize thermophilic and halophilic bacteria from İzmir/Dikili (Bademli) sea thermal spring in Turkey. This study was carried out in three stages: In the first stage, samples were taken from various stations (sea water, mud, sand etc.) for bacterial isolation using Brown Broth and thermus medium from the Bademli Sea Spring of Dikili District of İzmir Province. Phenotypic characterisation was performed by selecting microorganisms with different colony morphology from the obtained cultures. In the second stage, codes were given to bacterial strains with different morphological properties and their physiological tests (motility test, temperature, pH, oxygen parameters), biochemical tests (starch hydrolysis, casein hydrolysis, catalase test, citrate test, urease test, gelatine hydrolysis, oxidase test), salt tolerance and also the effect of different antibiotics were investigated. The obtained results were compared with the reference strains. In the third stage, chromosomal DNA isolation of the selected cells was performed and 16S rRNA analysis was performed using universal primers. The obtained sequences were compared using a BLAST search tool. The 16S rRNA sequence of the isolated strains was aligned with a reference sequence showing sequence homology from the NCBI database using the multiple sequence alignment program. The phylogenetic tree was constructed using MEGA 7 (Molecular Evolutionary Genetics Analysis) software. Sequence alignment of different species was performed using CLUSTAL W, and evolutionary distance matrices for the neighbor-joining method were calculated using the Kimura two-parameter model algorithm. 27strains with different colony and cell morphology were isolated in the study. These thermophilic and halophilic strains were determined to be close to Bacillus and Anoxybacillus species according to 16S rRNA analysis results.