title: Bacterial breakdown of benomyl. I. Pure cultures.
abstract: With different soil and water samples as inoculum and the benzimidazole fungicides benomyl (either as Benlate or as the pure compound) and thiabendazole as selective agents, a large number of, mainly fluorescent, Pseudomonas strains were isolated which nearly all were able to grow in a mineral medium with benomyl as the sole source of carbon. However, no growth occurred with any of a series of other benzimidazole compounds, viz. benzimidazole, 2-aminobenzimidazole (2-AB), thiabendazole and fuberidazole. Although benomyl--or rather its non-enzymatic breakdown product methyl benzimidazol-2-yl carbamate (MBC)--was partially degraded to 2-AB, most probably n-butylamine, which arises after splitting off of the butylcarbamoyl side chain, was the actual carbon source for the Pseudomonas isolates. When incorporated in a lactate medium, 2-AB markedly inhibited the growth of Pseudomonas spp. at a concentration of 250 microgram/ml, with complete inhibition being attained at 500 microgram/ml. For Bacillus spp. grown in liquid peptone media benzimidazole compounds were inhibitory at concentrations of 500-1000 microgram/ml, with a toxicity increasing in the order: benzimidazole less than thiabendazole less than MBC less than 2-AB.
mesh_terms: D001407:Bacillus / Q000254:growth & development / Q000378:metabolism*; D001542:Benomyl / Q000378:metabolism*; D001562:Benzimidazoles / Q000378:metabolism; D001673:Biodegradation, Environmental; D002219:Carbamates / Q000378:metabolism*; D055598:Chemical Phenomena; D002621:Chemistry; D003470:Culture Media; D007773:Lactates / Q000378:metabolism; D011549:Pseudomonas / Q000254:growth & development / Q000378:metabolism*; D012988:Soil Microbiology; D013045:Species Specificity; D014871:Water Microbiology
chemical_list: D001562:Benzimidazoles; D002219:Carbamates; D003470:Culture Media; D007773:Lactates; D001542:Benomyl