Toluene and xylene degradation by a denitrifying strain of Xanthomonas maltophilia with limited or no oxygen

A strain of Xanthomonas (Pseudomonas) maltophilia utilized toluene and xylene at the same rate in a well-mixed system containing excess nitrate and either 2% oxygen or no oxygen. Toluene utilization was much more rapid when 20% oxygen was provided. The data presented, as well as data in the literature, suggest that for the degradation of these aromatic hydrocarbons, limited amounts of oxygen provide no advantage over anoxic denitrification.