Comamonas thiooxidans (strain S23(T)) capable of oxidizing thiosulfate under a mixotrophic growth condition was isolated from a sulfur spring. DNA-DNA homology study showed 55% similarity with Comamonas testosteroni KCTC2990(T) and 52% with Comamonas composti LMG24008(T), the nearest phylogenetic relative (16S rRNA sequence similarity <97%). Comparative genomic fingerprinting by using ERIC and Rep-PCR further delineated species identity of the strain S23(T) for which Comamonas thiooxidans sp. nov. is proposed. In addition, thiosulfate oxidation potential of the strain S23(T) was compared with Comamonas testosteroni and Comamonas composti.

A bacterial isolate S23 capable of oxidizing thiosulfate was isolated from a sulfur spring. Strain S23 is gram-negative, aerobic, and motile. The G + C content of DNA is 61.4 mol%. The fatty acid composition and phylogenetic analysis of the 16S rRNA gene sequence of strain S23 showed that it is related to the members of the genus Comamonas, and most closely related to Comamonas testosteroni (99.9% sequence similarity). The isolate S23 exhibited thiosulfate oxidation under a mixotrophic growth condition. Polymerase chain reaction (PCR) using soxB-specific primers and DNA sequencing showed the presence of the soxB gene. This is the first report in Comamonas sp. showing thiosulfate oxidation under a mixotrophic growth condition.

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During a study of microbial diversity, a bacterial strain designated HT10, was isolated from sediment collected from an unexplored sulfur spring at Athamallik, Orissa, India. Various biochemical tests and 16S rDNA sequence analysis revealed that strain HT10 is Aeromonas caviae. The growth temperature of this strain ranged from 12 to 43°C and the optimum temperature was 30°C. The strain HT10 showed cytotoxic and α‐hemolytic activity. This is the first report on the isolation of Aeromonas caviae from sulfur spring.

The present study compares the efficacy of two different subspecies of Bacillus thuringiensis viz. aizawai and kurstaki, available as commercial preparations in market against different stages of Spodoptera litura. Leaf-dip bioassay was done to calculate the LC 50 values of both the preparations, while microbiological analysis and total protein content estimation were also performed to co-relate the results. B. thuringiensis aizawai was found to be more effective (LC 50 values being 0.505, 1.121, 5.009, 6.706 for 1 st , 2 nd , 3 rd , and 4 th instar, respectively) than kurstaki (LC 50 values being 1.121, 3.974, 6.897, 9.471 for 1 st , 2 nd , 3 rd , and 4 th instar, respectively). The efficacy was found to depend upon the number of viable spores in a particular preparation as well as on the total protein content of that particular subspecies. The preparation containing B.t.a was more effective because its viable spore counts as well as total protein content values (at different time intervals) were higher as compared to the preparation containing B.t.k. The growth rates for both the subspecies were almost the same, which didn't seem to affect their efficacy on S. litura.