Molecular evolution of thermophilic geobacillus species isolated from tattapani hotspring (India) and the worldwide distribution

Four thermophilic bacterial isolates PW11, PW12, PW13 and PS4 were isolated from Tattapani Hot Spring. The microbial isolates showed optimum growth at 70ºC and at pH 6-7. Both Na⁺ and K⁺ ions were detected at 0.11 M and 1.7 mM respectively in the hot spring water. Interestingly, two bacterial isolates PW12 and PW13 showed growth in the presence of 0.5M KCl, whereas PW12 could grow in the presence of 0.75 M KCl and 0.75 M NaCl. All the four thermophilic isolates were rod shaped Gram-positive bacteria, and were analyzed by randomly amplified polymorphic DNA (RAPD) using five random primers and produced PCR fragments ranging from 250 – 6000 bp in size. Further, PW11, PW12, PW13 and PS4 were analyzed by PCR amplification of gene encoding 16S rDNA. 16S rDNA sequence analysis by BLAST search identifies PW13 as Geobacillus thermoleovorans, PW11 as Geobacillus kaustrophilus, PS4 and PW12 as Geobacillus toebii with GenBank accession nos. KF751757, KF751758, KF751759, and KJ509869 respectively.