Metabolism of anthracene by a Rhodococcus species

A Rhodococcus sp. isolated from contaminated river sediment was investigate d to determine if the isolate could degrade high molecular mass polycyclic aromatic hydrocarbons. The Rhodococcus sp. was able to utilize anthracene ( 53%), phenanthrene (31%), pyrene (13%), and fluoranthene (5%) as sole sourc e of carbon and energy, but not naphthalene or chrysene. In a study of the degradation of anthracene by a Rhodococcus sp., the identification of ring- fission products indicated at least two ring-cleavage pathways. One results in the production of 6,7-benzocoumarin, previously shown to be produced ch emically from the product of meta cleavage of 1,2-dihydroxyanthracene, a pa thway which has been well established in Gram-negative bacteria. The second is an ortho cleavage of 1,2-dihydroxyanthracene that produces 3-(2-carboxy vinyl)naphthalene-2-carboxylic acid, a dicarboxylic acid rin.-fission produ ct. This represents a novel metabolic pathway only identified in Gram-posit ive bacteria. (C) 2001 Federation of European Microbiological Societies. Pu blished by Elsevier Science BY. All rights reserved.