Figure 2

Pathway of aerobic MTBE degradation. In bacteria, MTBE and also other ethers used as fuel oxygenates are initially attacked by various monooxygenases [20]. The resulting tert-butoxy methanol may spontaneously dismutate to tert-butanol and formaldehyde or is further oxidized to tert-butyl formate. The latter ester can be hydrolyzed to tert-butanol and formic acid. A second monooxygenase catalyzes the hydroxylation of tert-butanol to 2-methyl-1,2-propanediol which is oxidized via the corresponding aldehyde to 2-HIBA. The latter is then isomerized to the common metabolite 3-hydroxybutyryl-CoA [39]. For further details see also Figure 3b and c.