Paenochrobactrum gallinarii gen. nov., sp. nov., isolated from air of a duck barn, and reclassification of Pseudochrobactrum glaciei as Paenochrobactrum glaciei comb. nov.

A Gram-negative, rod-shaped, oxidase-positive, non-spore-forming, non-motile bacterium (Sa25(T)) was isolated from air of a duck barn. 16S rRNA gene and recA sequence analyses clearly placed the isolate in the vicinity of the Brucella-Ochrobactrum-Pseudochrobactrum group, with the closest relative being Pseudochrobactrum glaciei KMM 3858(T). This allocation was confirmed by analyses of the quinone system (ubiquinone Q-10), fatty acid data (major fatty acids C(18 : 1)omega7c and C(19 : 0) cyclo omega8c) and polar lipid profile (major components diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and unknown aminolipid AL1; moderate amounts of three unknown polar lipids, L1-L3, an unknown aminolipid and an unknown aminophospholipid APL2). The polyamine pattern of Sa25(T) exhibited the major compound putrescine and moderate amounts of spermidine; a similar polyamine pattern with the major compound putrescine was also detected in Pseudochrobactrum glaciei KMM 3858(T). DNA-DNA hybridization of strain Sa25(T) with Pseudochrobactrum glaciei KMM 3858(T) and the type strains of the other Pseudochrobactrum species showed values ranging from 50.3 to 24.8 %, and physiological and biochemical data clearly differentiated this isolate from the described Pseudochrobactrum species. Since Sa25(T) and Pseudochrobactrum glaciei KMM 3858(T) form a distinct lineage in the 16S rRNA gene sequence-based phylogenetic tree, and this separate position is supported by unique characteristics of their polyamine patterns and polar lipid profiles, we propose the novel genus Paenochrobactrum gen. nov., with the type species Paenochrobactrum gallinarii sp. nov. (type strain Sa25(T) =CCUG 57736(T) =CCM 7656(T)) and the reclassification of Pseudochrobactrum glaciei as Paenochrobactrum glaciei comb. nov. (type strain Pi26(T) =KMM 3858(T) =NRIC 0733(T) =JCM 15115(T)).