The diversity of fenitrothion-degrading bacteria active in soils from several distant locations in Japan was analyzed on the basis of 16S rRNA gene sequences. One hundred seventy fenitrothion-degrading isolates from four locations were assigned to five genera of the phylum Proteobacteria: Bartonella, Rhizobium, Burkholderia, Cupriavidus, and Pseudomonas. Bartonella, Cupriavidus, and Rhizobium strains were shown to degrade organophosphorus pesticides for the first time. Burkholderia strains were dominant in all soils. Bartonella strains degraded fenitrothion cometabolically, while all other strains utilized the pesticide, indicating that a potential for both complete and partial degradation of fenitrothion by bacteria exists in soil in Japan. Soil microcosms were prepared and exposed to repeated applications of fenitrothion. In each microcosm, one single Burkholderia strain was favored by this treatment and subsequently dominated the fenitrothion-degrading bacterial population.

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