title: Bacterial metabolism of para- and meta-xylene: oxidation of a methyl substituent.
abstract: Pseudomonas Pxy was isolated on p-xylene as sole source of carbon and energy. Substrates that supported growth were toluene, p-methylbenzyl alcohol, p-tolualdehyde, p-toluic acid, and the analogous m-methyl derivatives, including m-xylene. Cell extracts prepared from Pseudomonas Pxy after growth with either p-xylene or m-xylene oxidized the p- and m-isomers of tolualdehyde as well as p-methylbenzyl alcohol. The same cell extracts also catalyzed a "meta" fission of both 3- and 4-methylcatechol. Treatment of Pseudomonas Pxy with N-methyl-N'-nitro-N-nitrosoguanidine led to the isolation of two mutant strains. Pseudomonas Pxy-40, when grown on succinate in the presence of p-xylene, accumulated p-toluic acid in the culture medium. Under the same conditions Pseudomonas Pxy-82 accumulated p-toluic acid and also 4-methylcatechol. When Pseudomonas Pxy-82 was grown on succinate in the presence of m-xylene, 3-methylcatechol and 3-methylsalicylic acid were excreted into the culture medium. A pathway is proposed for the initial reactions utilized by Pseudomonas Pxy to oxidize p- and m-xylene.
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000445:Aldehyde Oxidoreductases / Q000378:metabolism; D001565:Benzoates / Q000378:metabolism; D002396:Catechols / Q000096:biosynthesis / Q000378:metabolism; D002474:Cell-Free System; D055598:Chemical Phenomena; D002621:Chemistry; D008745:Methylation; D009153:Mutagens; D009154:Mutation; D009604:Nitrosoguanidines; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000378:metabolism; D011549:Pseudomonas / Q000201:enzymology / Q000378:metabolism*; D013386:Succinates / Q000378:metabolism; D014050:Toluene / Q000378:metabolism; D014992:Xylenes / Q000378:metabolism*
chemical_list: D001565:Benzoates; D002396:Catechols; D009153:Mutagens; D009604:Nitrosoguanidines; D013386:Succinates; D014992:Xylenes; D014050:Toluene; D000429:Alcohol Oxidoreductases; D010105:Oxygenases; D000445:Aldehyde Oxidoreductases