THE MICROBIAL DEGRADATION OF AROMATIC PETROLEUM PRODUCTS

Nocardia OX was isolated on ortho-xylene as sole source of carbon and energy. Substrates that supported growth were toluene, benzoic acid, glucose, citrate, malate and acetate. Ortho-Xylene grown cells oxidized ortho-xylene, to cis-toluene dihydrodiol, 3,4-dimethylcatechol, pyrocatechol, 3- and 4-methylcatechol and several halogenated toluenes. Treatment of Nocardia OX with N-methyl-N'-Nitro-N- nitrosoguanidine led to the isolater of a mutant strain, Nocardia OX-2, which oxidized o-xylene to 3,4-dimethyl- catechol. The latter compound was isolated and characterized. 3,4-Dimethylcatechol was oxidized by cell extracts of Nocardia OX to 2-oxo-4-hydroxycaproic acid and propionaldehyde. A pathway is proposed for the degradation of o-xylene by Nocardia OX. Pseudomonas Pxy, an organism that can degrade p-xylene carries the genetic information for the synthesis of these catabolic enzymes on an extrachromosomal element (plasmid). The plasmid has been transferred to Pseudomonas putida PpGl by transduction and to a different Pseudomonas putida strain by conjugation. The recipient organisms acquired all of the p-xylene degradative enzymes as a result of the transmission of the plasmid. Physical evidence for the existence of the plasmid has not been obtained. Beijerinckia oxidizes dibenzothiophene through cis-1,2-dihydroxy-1, 2-dihydrobenzothiophene, 1,2-dihydroxybenzothiophene, trans-4(2-(3-hydroxy)-thianaphthenyl)-2-oxo-3-butenoic acid and 3-hydroxy-2-formylbenzothiophene. A mutant strain of Beijerinckia (strain B-836) oxidized dibenzothiophene to cis-1, 2-dihydroxy-1, 2-dihydrobenzothiophene and dibenzothiophene 5-oxide. Both compounds were isolated and characterized. Only the dihydrodiol derivative was metabolized by the wild type organism. A pathway for the degradation of dibenzothiophene is proposed.

  • Corporate Authors:

    University of Texas, Austin

    Cockrell Hall
    Austin, TX  USA  78712
  • Authors:
    • Gibson, D T
  • Publication Date: 1975-6-30

Media Info

  • Features: References;
  • Pagination: 50 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00098628
  • Record Type: Publication
  • Source Agency: Office of Naval Research
  • Report/Paper Numbers: #2 Ann Rpt.
  • Contract Numbers: N00014-67-A0126-0020
  • Files: TRIS
  • Created Date: Aug 13 1975 12:00AM