Corynebacterium lubricantis sp. nov., isolated from a coolant lubricant

Three Gram-positive, rod-shaped, oxidase-negative, non-spore-forming, non-motile bacteria (KSS-3Se^T, KSS-4Se and KSS-10Se) were isolated from a coolant lubricant. 16S rRNA gene sequence analyses revealed almost identical sequences, with only a few (<10 positions) differences for these three isolates. Comparisons showed the highest similarities to Corynebacterium pilosum NCTC 11862^T (97.6 % similarity with strain KSS-3Se^T). Similarities with other established Corynebacterium species were lower than 97.0 %. Chemotaxonomic data studied for strain KSS-3Se^T [polar lipids – major compounds phosphatidylglycerol and an unknown glycolipid, moderate amounts of phosphatidylinositol and diphosphatidylglycerol; polyamines (small amounts) – major compounds spermidine and spermine; quinones – significant amounts of menaquinones MK-9(H₂), MK-8(H₂) and MK-7(H₂); and major fatty acids – tuberculostearic acid (10-methyl C_{18 : 0}), C_{16 : 0} and C_{18 : 1}ω9c] were congruent with those reported for Corynebacterium. The strain showed differences in phenotype from C. pilosum. DNA–DNA hybridizations between KSS-3Se^T and C. pilosum DSM 20521^T yielded a relatedness of 22.9 % (20.4 % in the reciprocal assay). From these results, it is evident that the organisms represent a novel species, for which the name Corynebacterium lubricantis sp. nov. is proposed (type strain KSS-3Se^T =DSM 45231^T =CCUG 56567^T =CCM 7546^T).