Alternative pathways foro-xylene orm-xylene andp-xylene degradation in aPseudomonas stutzeri strain

Pseudomonas stutzeri OX1 is able to grow ono-xylene but is unable to grow onm-xylene andp-xylene, which are partially metabolized through theo-xylene degradative pathway leading to the formation of dimethylphenols toxic to OX1.P. stutzeri spontaneous mutants able to grow onm-xylene andp-xylene have been isolated. These mutants soon lose the ability to grow ono-xylene. Data from HPLC analyses and from induction studies suggest that in these mutantsm-xylene andp-xylene could be metabolized through the oxidation of a methyl substituent.P. stutzeri chromosomal DNA is shown to share homology with pWW0 catabolic genes. In the mutant strains the region homologous to pWW0 upper pathway genes has undergone a genomic rearrangement.Abbreviations BADH benzylalcohol dehydrogenase - cat catechol - C23O catechol 2,3-dioxygenase - 2,3-,3,4-,2,4-,2,6-,3,5-2,5-DMP 2,3-,3,4-,2,4-,2,6-,3,5-,2,5-dimethylphenol - 2-MBOH 2-methylbenzyl alcohol - 3-MBOH 3-methylbenzyl alcohol - 4-MBOH 4-methylbenzyl alcohol - m-,p-tol m-,p-toluate - o-,m-,p-xyl o-,m-,p-xylene