Quisquiliibacterium transsilvanicum gen. nov., sp. nov., a novel betaproteobacterium isolated from a waste-treating bioreactor.

A new betaproteobacterium, CGI-09, was isolated from an activated sludge bioreactor which treated landfill leachate. Based on 16S rRNA gene sequence analysis, the new strain shared the highest pairwise similarity values with members of the order Burkholderiales: Derxia gummosa IAM 13946 (family Alcaligenaceae), 93.7 % and Lautropia mirabilis DSM 11362 (family Burkholderiaceae), 93.6 %. Cells of strain CGI-09 were rod-shaped and non-motile. The new strain was oxidase and catalase positive and capable of reducing nitrate to nitrite. The predominant fatty acids were C16 : 1 ω7c, C16 : 0, cycloC17 : 0 and C18 : 1 ω7c, the major respiratory quinone was Q-8, and the detected polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and an unknown phospholipid. The G+C content of the genomic DNA of strain CGI-09 was 70.2 mol%. The new bacterium can be distinguished from the members of genera Derxia and Lautropia based on its non-motile cells, arginine dihydrolase activity, its high cyclo C17 : 0 fatty acid content and the lack of hydroxy fatty acids. On the basis of the phenotypic, chemotaxonomic and molecular data, strain CGI-09 is considered to represent a new genus and species within the family Burkholderiaceae, for which the name Quisquiliibacterium transsilvanicum gen. nov., sp. nov. is proposed. The type strain is CGI-09 (=DSM 29781=JCM 31785).