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 °C. The major fatty acids (≥10 %) of strain AIMA4^T were C_16:ω7c, C_16:0 and C_18:1ω7c. 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.