Survival and chlorpyrifos-degradation of strain Cupriavidus taiwanensis Lux-X1 in different type soils

Environmental pollution caused by pesticides is a world wide problem, and luciferase (luxAB) labeling is a powerful tool for tracing dynamic activity of microorganisms in the ecosystem. Experiments were conducted with strain Cupriavidus taiwanensis Lux-X1 that was labeled with gene luxAB, kan and ter to investigate the survival and chlorpyrifos-degrading activity of the strain in three kinds of soils, shangjiang black soil, yellow cinnamon soil and red soil, respectively. The results indicated that the colonies of strain Lux-X1 which have been inoculated in soils could be obtained successfully on the selective plate with antibiotics, and all the colonies emitted fluorescence induced by capraldehyde in darkness. The facts showed luxAB gene could be expressed in cells of strain Lux-X1 and the luminescence method (luxAB) is a practicable tool for tracing dynamic activity of strain Lux-X1 in the ecosystem. Survival experiments of strain Lux-X1 in different soils showed that strain Lux-X1 stably survived in these three kinds of soils after 30d, and the viable amount of Lux-X1 in shangjiang black soil was higher than those in other two soils. The 500 mg/L chlorpyrifos added to three soils was degraded by Lux-X1 inoculated in soils after 16 d, and the soil order, reflecting degradation effect of Lux-X1 was as following: shangjiang black soil > yellow cinnamon soil > red soil, the degradation rate constant of chlorpyrifos were 0.3185 d -1 , 0.2206 d -1 , 0.1732 d -1 respectively under the same initial concentration of chlorpyrifos and bacterium amount. Strain Lux-X1 could decompose chlorpyrifos with much high concentration in less time. Utilization of strain Cupriavidus taiwanensis Lux-X1 as bioremediation material in heavy polluted area with chlorpyrifos is feasible.