Haloalkane degradation

Curragh H, O Flynn, MJ Larkin, TM Stafford, JTG Hamilton, DB Harper (1994) Haloalkane degradation and assimilation by Rhodococcus rhodochrous NCIMB 13064. Microbiology (UK) 140 1433-1442. 

A number of haloalkanes including dichloromethane, chloroform, 1,1-dichloroethane and 1,2-dichloroethane may be degraded by the soluble MMO system of Methylosinus trichosporium (Oldenhuis et al. 1989). 

Janssen DB, D Jager, B Witholt (1987) Degradation of -haloalkanes and a,co-dihaloalkanes by wild-type and mutants of Acinetobacter sp. strain GJ70. Appl Environ Microbiol 53 561-566. 

Nagata Y, Z Prokop, Y Sato, P Jerabek, A Kumar, Y Ohtsubo, M Tsuda, J Damborsky (2005) Degradation of b-hexachlorocyclohexane by haloalkane dehalogenase LinB from Sphingomonas paucimobilis UT 26. Appl Environ Microbiol 71 2183-2185. 

The use of toluene to induce oxygenation of haloalkanes has been discussed in Chapter 7, Part 3, and probes for toluene-2-monooxygenase have been used to evaluate the potential nnmber of TCE-degrading organisms in an aquifer (Fries et al. 1997b). In this study, repetitive extragenic palindromic PCR (REP-PCR) (de Bruijn 1992) of isolates was used to classify their metabolic capability. 

Janssen, D.B., Jager, D., and Wilholt, B. Degradation of u-haloalkanes and a,(o-dihaloalkanes by wild type and mutants of Aclnetobactersp. sttain GJ70, Appl. Environ. Microbiol, 53(3) 561-566, 1987. 

The first term, representing acid-"catalyzed" hydrolysis, is important in reactions of carboxylic acid esters but is relatively unimportant in loss of phosphate triesters and is totally absent for the halogenated alkanes and alkenes. Alkaline hydrolysis, the mechanism indicated by the third term in Equation (2), dominates degradation of pentachloroethane and 1,1,2,2-tetrachloroethane, even at pH 7. Carbon tetrachloride, TCA, 2,2-dichloropropane, and other "gem" haloalkanes hydrolyze only by the neutral mechanism (Fells and Molewyn-Hughes, 1958 Molewyn-Hughes, 1953). Monohaloalkanes show alkaline hydrolysis only in basic solutions as concentrated as 0.01-1.0 molar OH- (Mabey and Mill, 1978). In fact, the terms in Equation(2) can be even more complex both elimination and substitution pathways can operate, leading to different products, and a true unimolecular process can result from initial bond breaking in the reactant molecule. 

Nagata, Y., K. Miyauchi, J. Damborsky, K. Manova, A. Ansorgova, and M. Takagi. 1997. Purification and characterization of a haloalkane dehalogenase of a new substrate class from a y-hexachlorocyclohexane-degrading bacterium, Sphin-gomonas paucimobilis UT26. Appl. Environ. Microbiol. 63 3703-3710. 

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