Caenimicrobium hargitense gen. nov., sp nov., a new member of the family Alcaligenaceae (Betaproteobacteria) isolated from activated sludge

A new betaproteobacterium, CGII-59m2(T), was isolated from an activated sludge bioreactor which treated landfill leachate. The 16S rRNA gene sequence analysis revealed that strain CGII-59m2(T) belonged to the family Alcaligenaceae and shared the highest pairwise similarity values with Parapusillimonas granuli LMG 24012(T) (97.7 %), various species of the genus Bordetella (97.3-97.0 %) and Candidimonas nitroreducens LMG 24812(T) (97.0 %). Cells of strain CGII-59m2(T) were rod-shaped, non-motile, and oxidase-and catalase-positive. The predominant fatty acids were C-16 : 1 omega 7c, C-16 : 0, cyclo C-17 : 0 and C-18 : 1 omega 7c, the major respiratory quinone was Q-8, and the main polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unknown phospholipid. The G+C content of the genomic DNA of strain CGII-59m2(T) was 62.3 mol%. The new bacterium can be distinguished from the closely related type strains based on its non-motile cells and its high C-16 : 1 omega 7c fatty acid content. On the basis of the phenotypic, chemotaxonomic and molecular data, strain CGII-59m2 T is considered to represent a novel species of a new genus, for which the name Caenimicrobium hargitense gen. nov., sp. nov. is proposed. The type strain is CGII-59m2(T) (=DSM 29806(T) =NCAIM B. 02615(T)).