Halococcus sediminicola sp. nov., an extremely halophilic archaeon isolated from a marine sediment

A novel, red-pigmented and coccoid haloarchaeon, designated strain CBA1101(T), was isolated from a marine sediment. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CBA1101(T) is most closely related to the genus Halococcus in the family Halobacteriaceae. Strain CBA1101(T) had a highest 16S rRNA gene sequence similarity of 98.4 % with Halococcus dombrowskii DSM 14522(T), followed by 93.7-98.3 % with sequences of other type strains in the genus Halococcus. The RNA polymerase subunit B' gene sequence similarity of strain CBA1101(T) with that of Halococcus qingdaonensis JCM 13587(T) is 89.5 % and lower with those of other members of the genus Halococcus. Strain CBA1101(T) was observed to grow at 25-40 °C, pH 6.0-9.0 and in the presence of 15-30 % (w/v) NaCl, with optimal growth at 35-40 °C, pH 7.0 and with 20 % NaCl. The cells of strain CBA1101(T) are Gram-negative and did not lyse in distilled water. The major polar lipids were identified as phosphatidylglyerol, phosphatidylglycerol phosphate methyl ester, sulfated diglycosyl diether, unidentified phospholipids and unidentified glycolipids. The genomic DNA G+C content was determined 66.0 mol%. The DNA-DNA hybridization experiment showed that there was less than 40 % relatedness between strain CBA1101(T) and the reference species in the genus Halococcus. Based on this polyphasic taxonomic analysis, strain CBA1101(T) is considered to represent a new species in the genus Halococcus, for which the name Halococcus sediminicola sp. nov. is proposed. The type strain is CBA1101(T) (=JCM 18965(T) = CECT 8275(T)).