m-Cresol
Cresol is a mixture of o-, p-, and m-cresol, and is obtained from coal tar or petroleum. These isomers are used as a disinfectants, textile scouring agents, surfactants and as intermediates in the manufacture of salicylaldehyde, coumarin, and herbicides. Creosote is a less refined petrochemical mixture containing cresol. It is used as a fungicide and a wood preservative for railroad ties, telephone poles, and marine pilings. Despite their chemical similarity, cresol isomers are degraded by bacteria through different pathways. One intermediate in this pathway, 3-hydroxybenzyl alcohol, is also an intermediate in the biosynthetic pathway of patulin ([http://www.ncbi.nlm.nih.gov/pubmed/6988382|Grootwassink & Gaucher, 1980]), a toxin and antiviral agent produced by some molds such as Penicillium patulinum. When grown on m-cresol as a sole carbon source, P. putida 9869 metabolizes the compound via the meta pathway with 3-methylcatechol as an intermediate ([http://www.ncbi.nlm.nih.gov/pubmed/1123316|Hopper et al., 1975]). It has been shown that Pseudomonas picketti also degrade m-cresol via 3-methylcatechol, as presented in the Toluene Pathway ([http://www.ncbi.nlm.nih.gov/pubmed/1892384|Shields et al., 1991]). [http://www.ncbi.nlm.nih.gov/pubmed/1123316|Hopper and Taylor (1974)] have also reported that P. putida 9869, when grown on 3,5-xylenol as a sole carbon source, metabolizes m-cresol via the gentisate pathway, as depicted in this text map. The genes coding for these enzymes are believed to be contained on a plasmid larger than the TOL plasmid which codes enzymes capable of degrading a many aromatic compounds ([http://www.ncbi.nlm.nih.gov/pubmed/6989805|Hopper et al., 1980]).