Plasmid-Mediated Dimethoate Degradation byBacillus licheniformisIsolated From a Fresh Water FishLabeo rohita

[摘要] TheBacillus licheniformisstrain isolated from the intestine ofLabeo rohitaby an enrichment technique showed capability of utilizing dimethoate as the sole source of carbon. The bacterium rapidly utilized dimethoate beyond 0.6 mg/mL and showed prolific growth in a mineral salts medium containing 0.45 mg/mL dimethoate. The isolatedB licheniformisexhibited high level of tolerance of dimethoate (3.5 mg/mL) in nutrient broth, while its cured mutant did not tolerate dimethoate beyond 0.45 mg/mL and it was unable to utilize dimethoate. The wildB licheniformisstrain transferred dimethoate degradation property toE coliC600 (Nar, F−) strain. The transconjugant harbored a plasmid of the same molecular size (approximately 54 kb) as that of the donor plasmid; the cured strain was plasmid less. Thus a single plasmid of approximately 54 kb was involved in dimethoate degradation. Genes encoding resistance to antibiotic and heavy metal were also located on the plasmid.

[学科分类] 基础医学