RHODOCOCCUS PERCOLATUS SP-NOV, A BACTERIUM DEGRADING 2,4,6-TRICHLOROPHENOL

A bacterial strain that was able to mineralize 2,4,6-trichlorophenol w as isolated from a chlorophenol-fed percolator and was identified as a member of the genus Rhodococcus on the basis of chemotaxonomic charac teristics and 16S RNA phylogenetic inference data, This organism (stra in MBS1(T) [T = type strain]) exhibited a typical irregular rod-coccus cycle, and the cells had fimbria-like structures on their surfaces, T he diagnostic cell wall amino acid was meso-diaminopimelic acid, and t he sugars were arabinose and galactose; the mycolic acids contained 46 to 54 carbon atoms, The main menaquinone was MK-8(H-2), and MK-9(H-2) was a minor component, The cellular phospholipids were phosphatidylet hanolamine, phosphatidylinositol, phosphatidylinositolmannoside, phosp hatidylglycerol, and diphosphatidylglycerol. Tuberculostearic acid was present. The whole-cell fatty acids were straight-chain acids with 14 to 18 C atoms. The G + C content of the DNA was 67.4 mol%. This organ ism grew on sucrose, pyruvate, and 2,4,6-trichlorophenol, and it oxidi zed a large number of carbon compounds, including catechol, 3-hydroxyp henylacetic acid, and phenol. It also exhibited beta-galactosidase, ur ease, and 2-acetyl-lactate decarboxylase activities, On a phylogenetic tree that was based on 16S ribosomal DNA gene sequences strain MBS1(T ) was found among the rhodococci on an independent branch, On the basi s of the chemotaxonomic and phenotypic characteristics of strain MBS1( T) and its phylogenetic position we suggest that this bacterium should be placed in a new species, Rhodococcus percolatus; the specific epit het was chosen because the organism was isolated by using an enriched percolator, The type strain is strain MBS1.