1,3-dichloropropene, degradation

The degradation of 2- and 3-chloroacrylate displays novel features. The degradation of 2-chloro-acrylate by Burkholderia sp. strain WS is initiated by a 2-haloacrylate reductase with the formation of (5)-2-chloropropionate that undergoes dehalogenation to (J )-lactate (Kurata et al. 2005). The degradation of 1,3-dichloropropene by Pseudomonas pavonaceae (cichorii) strain 170 involves a series of steps by which tra 5 -3-chloroacrylate is formed (Poelarends et al. 1998). This was degraded... 

Poelarends GJ, M Wilkens, MJ Larkin, JD van Elsas, DB Janssen (1998) Degradation of 1,3-dichloropropene by Pseudomonas cichorii 170. Appl Environ Microbiol 64 2931-2936. 

Dichloropropene is released into the air and in wastewater during its production and use as a soil fumigant and chemical intermediate. 1,3-Dichloropropene may also leach into groundwater. Considerable variation in the amounts of 1,3-dichloropropene lost by volatilization and degradation can be expected depending on the method of application, soil type, moisture and temperature. It has been detected in low levels in ambient air and drinking-water (United States National Library of Medicine, 1997). 

Dichloropropene is mobile and persistent, particularly in colder climates. When injected into the soil, its mobility is controlled by temperature, soil type, and moisture. Even though volatilization occurs from the soil surface, most 1,3-dichloropropene is degraded through hydrolysis to 3-dichloroallyl alcohol. The overall half-life of the compound in soil ranges from a few days to more than 9 weeks depending on conditions. Adsorption to sediment and bioconcentration in fish are not important processes. 

Figure 1 Three pathways for degradation of halogenated compounds, (a) The 1,2-dichloroethane catabolic pathway in Xanthobacterautotrophicus GJ10. (b) The 1,3-dichloropropene catabolic pathway in Pseudomonaspavonaceae 170. (c) The 7-HCH catabolic pathway in Sphingomonas paucimobilis UT26.

CaaD is part of a pathway that is responsible for the degradation of the nematocide 1,3-dichloropropene in the soil bacterium Pseudomonas pavonaceae 170 (Figure l(b)). Its metabolic function is to convert trans-l>-chloroacrylate into malonate semialdehyde (4 at 3 s, 1.2 x lO moH Is ), which is probably the... 

---