Degradation of 1,3-dichloropropene by pseudomonas cichorii 170.
The gram-negative bacterium Pseudomonas cichorii 170, isolated from soil that was repeatedly treated with the nematocide 1, 3-dichloropropene, could utilize low concentrations of 1, 3-dichloropropene as a sole carbon and energy source. Strain 170 was also able to grow on 3-chloroallyl alcohol, 3-chloroacrylic acid, and several 1-halo-n-alkanes. This organism produced at least three different dehalogenases: a hydrolytic haloalkane dehalogenase specific for haloalkanes and two 3-chloroacrylic acid dehalogenases, one specific for cis-3-chloroacrylic acid and the other specific for trans-3-chloroacrylic acid. The haloalkane dehalogenase and the trans-3-chloroacrylic acid dehalogenase were expressed constitutively, whereas the cis-3-chloroacrylic acid dehalogenase was inducible. The presence of these enzymes indicates that 1, 3-dichloropropene is hydrolyzed to 3-chloroallyl alcohol, which is oxidized in two steps to 3-chloroacrylic acid. The latter compound is then dehalogenated, probably forming malonic acid semialdehyde. The haloalkane dehalogenase gene, which is involved in the conversion of 1,3-dichloropropene to 3-chloroallyl alcohol, was cloned and sequenced, and this gene turned out to be identical to the previously studied dhaA gene of the gram-positive bacterium Rhodococcus rhodochrous NCIMB13064. Mutants resistant to the suicide substrate 1,2-dibromoethane lacked haloalkane dehalogenase activity and therefore could not utilize haloalkanes for growth. PCR analysis showed that these mutants had lost at least part of the dhaA gene.
Department of Biochemistry, University of Groningen, 9747 AG Groningen, The Netherlands.
G J
GJ
Poelarends
M
M
Wilkens
M J
MJ
Larkin
J D
JD
van Elsas
D B
DB
Janssen
D000473:Alkanes / Q000378:metabolism; D000498:Allyl Compounds / Q000378:metabolism*; D001673:Biodegradation, Environmental; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D005798:Genes, Bacterial; D006843:Hydrocarbons, Chlorinated; D006867:Hydrolases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism*; D009154:Mutation; D010957:Plasmids / Q000235:genetics; D011549:Pseudomonas / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012988:Soil Microbiology
D000473:Alkanes; D000498:Allyl Compounds; D006843:Hydrocarbons, Chlorinated; D007306:Insecticides; C023891:1,3-dichloro-1-propene; D006867:Hydrolases; C046137:haloalkane dehalogenase