Pseudochelatococcus lubricantis gen. nov., sp. nov. and Pseudochelatococcus contaminans sp. nov. from coolant lubricants

Abstract

Two Gram-negative, rod-shaped, non-spore-forming bacteria, isolated from metal working fluids were investigated to determine their taxonomic positions. On the basis of 16S rRNA gene sequence phylogeny, both strains (MPA 1113T and MPA 1105T) formed a distinct cluster with 97.7 % sequence similarity between them, which was in the vicinity of members of the genera Methylobacterium , Camelimonas , Chelatococcus , Bosea , Salinarimonas and Microvirga to which they showed low sequence similarities (below 94 %). The predominant compounds in the polyamine pattern and in the quinone system of the two strains were spermidine and ubiquinone Q-10, respectively. The polar lipid profiles were composed of the major compounds: phosphatidylmonomethylethanolamine, phosphatidylglycerol, phosphatidylcholine, major or moderate amounts of diphosphatidylglycerol, two unidentified glycolipids and three unidentified aminolipids. Several minor lipids were also detected. The major fatty acids were either C19 : 0 cyclo ω8c or C18 : 1ω7c. The results of fatty acid analysis and physiological and biochemical tests allowed both, the genotypic and phenotypic differentiation of the isolates from each other, while the chemotaxonomic traits allowed them to be differentiated from the most closely related genera. In summary, low 16S rRNA gene sequence similarities and marked differences in polar lipid profiles, as well as in polyamine patterns, is suggestive of a novel genus for which the name Pseudochelatococcus gen. nov. is proposed. MPA 1113T ( = CCM 8528T = LMG 28286T = CIP 110802T) and MPA 1105T ( = CCM 8527T = LMG 28285T) are proposed to be the type strains representing two novel species within the novel genus, Pseudochelatococcus gen. nov., for which the names Pseudochelatococcus lubricantis sp. nov. and Pseudochelatococcus contaminans sp. nov. are suggested, respectively.