Methylobrevis pamukkalensis gen. nov., sp. nov., a halotolerant restricted facultative methylotroph isolated from saline water.

An aerobic halotolerant restricted facultatively methylotrophic bacterium was isolated from a saline hot spring in Pamukkale, Turkey, and designated strain PK2(T). The cells of this strain were Gram-stain-negative, asporogenous, motile short rods multiplying by binary fission. They utilized methanol, methylamine and mannitol as carbon and energy sources. The organism grew optimally at 30 °C in media containing 85 mM NaCl and at pH 7.5-8.0. C1 compounds were assimilated via the isocitrate-lyase-positive variant of the serine pathway. Poly-ß-hydroxybutyrate and the compatible solute ectoine were found in the cells. The dominant phospholipids were phosphatidylethanolamine and phosphatidylmonomethylethanolamine. The major cellular fatty acids of methanol-grown cells were C(18 : 1)ω7 and C(16 : 1)ω7c. The main ubiquinone was Q-10. The DNA G+C content was 67.9 mol% (T(m)). The 16S rRNA gene sequence suggests that strain PK2(T) is affiliated with the order Rhizobiales within the class Alphaproteobacteria , being most closely related to Mesorhizobium gobiense CCBAU 83330(T) (94% similarity). A novel genus and species, Methylobrevis pamukkalensis gen. nov., sp. nov., is proposed on the basis of phenotypic and genotypic data, with PK2(T) (VKM B-2849(T) = JCM 30229(T)) as the type strain.

Methyloligella halotolerans gen. nov., sp. nov. and Methyloligella solikamskensis sp. nov., two non-pigmented halotolerant obligately methylotrophic bacteria isolated from the Ural saline environments.

Two newly isolated halotolerant obligately methylotrophic bacteria (strains C2(T) and SK12(T)) with the serine pathway of C1 assimilation are described. The isolates are strictly aerobic, Gram negative, asporogenous, non-motile rods, forming rosettes, multiplying by binary fission. Mesophilic and neutrophilic, accumulate intracellularly compatible solute ectoine and poly-ß-hydroxybutyrate. The novel strains are able to grow at 0 up to 16% NaCl (w/v), optimally at 3-5% NaCl. The major cellular fatty acids are C18:1ω7c and C19:0cyc and the prevailing quinone is Q-10. The predominant phospholipids are phosphatidylcholine, phosphatidylglycerol, phosphatidyldimethylethanolamine and phosphatidylethanolamine. Assimilate NH4(+) by glutamate dehydrogenase and via the glutamate cycle (glutamine synthetase and glutamate synthase). The DNA G+C contents of strains C2(T) and SK12(T) are 60.9 and 60.5 mol% (Tm), respectively. 16S rRNA gene sequence similarity between the two new isolates are 99% but below 94% with other members of the Alphaproteobacteria thus indicating that they can be assigned to a novel genus Methyloligella. Rather low level of DNA-DNA relatedness (53%) between the strains C2(T) and SK12(T) indicates that they represent two separate species of the new genus, for which the names Methyloligella halotolerans gen. nov., sp. nov. and Methyloligella solikamskensis sp. nov. are proposed. The type strain of Methyloligella halotolerans is C2(T) (=VKM B-2706(T)=CCUG 61687(T)=DSM 25045(T)) and the type strain of Methyloligella solikamskensis is SK12(T) (=VKM B-2707(T)=CCUG 61697(T)=DSM 25212(T)).