title: Enantioselective degradation of the chiral fungicides metalaxyl and furalaxyl by Brevibacillus brevis.
abstract: For almost four decades, the chiral fungicides metalaxyl and furalaxyl have been in use in plant protection on a global scale. Both substances are distributed as racemic mixtures, yet the desirable interference in nucleic acid synthesis of harmful fungi only occurs by the (-)-R-enantiomer. As enantioselective degradation in Scheyern (Germany) and Yaoundé (Cameroon) soils has been documented, the influence of 50 isolated microorganisms on the R/S ratio was investigated. A high-pressure liquid chromatography method with a chiral column to separate enantiomers of metalaxyl and furalaxyl, and subsequent detection by tandem mass spectrometry, was employed. Only one of these microorganisms, a strain of Brevibacillus brevis, showed an enantioselective degradation pattern in liquid culture; the respective (-)-R-enantiomers were preferably degraded. Moreover, (-)-R-furalaxyl was degraded faster in cultures supplemented simultaneously with both fungicides of the same concentration.
authors.affiliation: Institute of Environmental Research (INFU) of the Faculty of Chemistry, TU Dortmund, Dortmund, Germany.
authors.forename: Lutz
authors.initials: L
authors.lastname: Sulimma
authors.forename: Anke
authors.initials: A
authors.lastname: Bullach
authors.forename: Souvik
authors.initials: S
authors.lastname: Kusari
authors.forename: Marc
authors.initials: M
authors.lastname: Lamshöft
authors.forename: Sebastian
authors.initials: S
authors.lastname: Zühlke
authors.forename: Michael
authors.initials: M
authors.lastname: Spiteller
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives / Q000737:chemistry; D001673:Biodegradation, Environmental; D058675:Brevibacillus / Q000378:metabolism*; D005659:Fungicides, Industrial / Q000737:chemistry* / Q000378:metabolism*; D005663:Furans / Q000737:chemistry; D012988:Soil Microbiology; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism
chemical_list: D005659:Fungicides, Industrial; D005663:Furans; C028175:metalaxyl; C490004:furalaxyl; D000409:Alanine