Enzyme Induction by Growth on Structurally Unrelated Compounds

Enzyme Induction by Growth on Structurally Unrelated Compounds 

Enzymes necessary for the metabolism of a substrate may be induced by growth on structurally unrelated compounds. In the examples used for illustration, monooxygenases play a cardinal role as a result of the versatility of methane monooxygenase, while monooxygenases that may be involved in toluene degradation are discussed in Chapter 3, Part 1 and Chapter 8, Part 1. 

The last example is mediated by a monooxygenase that can be induced by benzene, toluene, and ethylbenzene, and also by xylenes and styrene. A plausibly analogous situation exists for strains of Pseudomonas sp. and Rhodococcus erythropolis that were obtained by enrichment with isopropylbenzene, and that could be shown to oxidize trichloroethene (Dabrock et al. 1992). In addition, one of the pseudomonads could oxidize 1,1-dichloroeth-ene, vinyl chloride, trichloroethane, and 1,2-dichloroethane. 

Methane, butane, and chloroform. Cells of Methylosinus trichosporium grown with methane and of Pseudomonas butanovora md My cobacterium vaccae grown with butane were able to partially degrade chloroform (Hamamura et al. 1997). Again this may be the result of the induction of monooxygenase activity. 

Strain G4/PR1 of Burkholderia cepacia in which the synthesis of toluene-2-monooxygenase is constitutive is able to degrade a number of ethers including diethyl ether and n-butyl methyl ether but not t-butyl methyl ether (Hur et al. 1997). 

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