title: [Consumption of the triazine herbicide atrazine by laccase and laccase-free variants of the soil fungus Mycelia sterilia INBI-2-26].
abstract: Asporogenic fungus Mycelia sterilia INBI 2-26 isolated from tropical soils with high residual dioxin content (as a result of Agent Orange defoliant treatment during the Vietnamese-American war) and capable of atrazine decomposition was treated to obtain protoplasts. This technique resulted in isolation of laccase-positive and laccase-negative clones. Atrazine consumption by liquid surface cultures of Mycelia sterilia INBI 2-26 was monitored by using enzyme immune assay and reversed phase HPLC. Atrazine (20 micrograms/l) stimulated fungal growth. Laccase-positive clone consumed up to 80% of atrazine within four weeks. However, no correlation of atrazine consumption and laccase activity in the culture medium was observed. Moreover, the laccase-negative clone was also capable of consuming at least 60-70% of atrazine within three weeks. Surprisingly, in the corresponding control set (cultivation of laccase-negative clone without atrazine) an unidentified metabolite having a retention time and UV-spectrum similar to those of atrazine was also found. It was concluded that the presence of laccase was not a crucial factor in atrazine consumption by this fungus.
authors.affiliation: Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow, 119071 Russia.
authors.forename: L G
authors.initials: LG
authors.lastname: Vasil'chenko
authors.forename: V V
authors.initials: VV
authors.lastname: Khromonygina
authors.forename: O V
authors.initials: OV
authors.lastname: Koroleva
authors.forename: E O
authors.initials: EO
authors.lastname: Landesman
authors.forename: V V
authors.initials: VV
authors.lastname: Gaponenko
authors.forename: T A
authors.initials: TA
authors.lastname: Kovaleva
authors.forename: Iu P
authors.initials: IuP
authors.lastname: Kozlov
authors.forename: M L
authors.initials: ML
authors.lastname: Rabinovich
mesh_terms: D001280:Atrazine / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D005658:Fungi / Q000201:enzymology / Q000378:metabolism*; D006540:Herbicides / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D042845:Laccase; D010088:Oxidoreductases / Q000378:metabolism*
chemical_list: D003470:Culture Media; D006540:Herbicides; D010088:Oxidoreductases; D042845:Laccase; D001280:Atrazine