Sulfitobacter pontiacus subsp. fungiae subsp. nov., Isolated from Coral Fungia seychellensis from Andaman Sea, and Description of Sulfitobacter pontiacus subsp. pontiacus subsp. nov.

Abstract

Two closely related aerobic, Gram reaction-negative rod-shaped bacteria (S7-75T and S7-80) were isolated from mucus of coral Fungia seychellensis from Andaman Sea, India. Heterotrophic growth on marine agar was observed at 4-35 °C and pH 6.5-10.5; optimum growth occurred at 25-30 °C and pH 7-8. 16S rRNA sequence analysis confirmed the strains belonged to the genus Sulfitobacter and the two isolates shared more than 99.28% pairwise sequence similarity. DNA-DNA similarity between two isolates S7-75T and S7-80 was above 96%. Strain S7-75T showed maximum 16S rRNA similarity of 99.64% with Sulfitobacter pontiacus LMG 19752T. However, DNA-DNA relatedness between strain S7-75T and S. pontiacus LMG 19752T confirmed the placement of strain S7-75T as subspecies under the species S. pontiacus. Further, pulsed-field gel electrophoresis (PFGE), REP-PCR, ERIC-PCR fingerprint patterns and lipid profiles also differentiated strain S7-75T from the reference strain of S. pontiacus LMG 19752T. The DNA G+C content was 59.8mol%. Q10 was the major respiratory quinone. Based on polyphasic analysis, the isolate S7-75T represents a subspecies of S. pontiacus for which the name S. pontiacus subsp. fungiae subsp. nov. is proposed with S7-75T (=JCM 31094T = LMG 29158T) as type strain.