Brachymonas chironomi sp. nov., isolated from a chironomid egg mass, and emended description of the genus Brachymonas.

A Gram-negative, aerobic, chemo-organotrophic, catalase- and oxidase-positive strain, designated AIMA4(T), was isolated from a chironomid (Diptera; Chironomidae) egg mass which was sampled from a waste stabilization pond in northern Israel. Phylogenetic analysis based on the 16S rRNA gene placed strain AIMA4(T) in the genus Brachymonas (class Betaproteobacteria). Strain AIMA4(T) shared 16S rRNA gene sequence similarity values of 96.9 % with Brachymonas denitrificans JCM 9216(T) and <95.7 % with the type strains of other genera. Strain AIMA4(T) was found to be a non-motile coccobacillus or rod that did not grow under anaerobic conditions and did not produce acid from carbohydrates. Growth was observed at salinities from 0 to 2.5 % (w/v) NaCl, at pH values from 5.0 to 9.0 and at temperatures from 18 to 37 degrees C. The major fatty acids (>10 %) of strain AIMA4(T) were C(16 : 1)omega7c, C(16 : 0) and C(18 : 1)omega7c. Phosphatidylethanolamine, phosphatidylglycerol and phosphatidylserine were the predominant components of the polar lipids. The major ubiquinone was Q-8. On the basis of phenotypic properties and phylogenetic distinctiveness, strain AIMA4(T) (=LMG 24400(T)=DSM 19884(T)) was classified in the genus Brachymonas as the type strain of a novel species for which the name Brachymonas chironomi sp. nov. is proposed.