Toluene plasmid/chromosomal genes

In the degradation of toluene, the plasmid-borne genes encode enzymes for the oxidation to benzoate, whereas those that are chromosomally borne encode ring 2,3-dioxygenation. 

The degradation of toluene In this example, different pathways are used by the plasmid and chromosomally borne genes — side-chain oxidation to benzoate and ring 2,3-dioxygenation, respectively (Chapter 6, Section 6.2.1). 

For monoalkylated benzenes, there are two additional factors (1) the genes may be either chromosomal or carried on plasmids and (2) oxidation may be initiated either on the aromatic ring or at the alkyl substituent. For example, toluene may be degraded by several different pathways. 

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