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Although cadusafos, an aliphatic organophosphorus (OP) insecticide, is not approved by the European commission, it is used in several countries and sometimes detected as a residue in soils and agricultural products. In this study, two cadusafos-degrading Sphingobium sp. strains, K22212 and Cam5-1, were isolated and characterized for use as detoxifying agents of the insecticide. Both strains degraded 100 mg L−1 of cadusafos in mineral medium within 12 h through a common metabolite, which was supposed to be dimerized thiophosphates based on its molecular weight. Degradation of cadusafos increased cell growth for Cam5-1 but not for K22212. K2212 and Cam5-1 degraded cadusafos in soil (15 mg kg−1 dry soil) within 5 and 2 days, respectively. Both strains also degraded ethoprophos, phenthoate and phorate but not chlorpyrifos and diazinon, indicating that they are specialized for degradation of OP insecticides with at least one single bond connecting phosphorus and sulfur atoms (P S bond). For both strains, the degradation rate was the largest for ethoprophos, followed by cadusafos, phenthoate, and phorate. Our results indicate that these bacterial strains are effective degraders of OP insecticides with P S bonds, and in particular, Cam5-1 is more promising for removal of the OP insecticides in soils.

The bacterial strain Bacillus velezensis GH1-13, isolated from rice paddy soil in Korea, has been shown to promote plant growth and have strong antagonistic activities against pathogens. Here, we report the complete genome sequence of GH1-13, revealing that it possesses a single 4,071,980-bp circular chromosome with 46.2% GC-content. The chromosome encodes 3,930 genes, and we have also identified a unique plasmid in the strain that encodes a further 104 genes (71,628bp and 31.7% GC-content). The genome was found to contain various enzyme-encoding operons, including indole-3-acetic acid (IAA) biosynthesis proteins, 2,3-butanediol dehydrogenase, various non-ribosomal peptide synthetases, and several polyketide synthases. These properties are responsible for the promotion of plant growth and the biosynthesis of secondary metabolites. They therefore have multiple beneficial effects that could be applied to agriculture. Through curing, we found that the unique plasmid of GH1-13 has important roles in the production of phytohormones, such as IAA, and in shaping phenotypic and physiological characteristics. The plasmid therefore likely influences the biological activities of GH1-13. The complete genome sequence of B. velezensis GH1-13 contributes to our understanding of this beneficial strain and will encourage research into its development for agricultural or biotechnological applications, enhancing productivity and crop quality.