[Risk assessment for environmental release of genetically engineered microorganism m-CDS-1]

To assess the environmental release risk of genetically engineered microorganism Sphingomonas sp. m-CDS-1.

Pesticides detection, plates counting, most probable number-PCR (MPN-PCR) and denaturing gradient gel electrophoresis (DGGE) were used to study the pesticides degrading effects, the decline dynamics of m-CDS-1, and the effects of release of m-CDS-1 on community structure of soil microorganisms.

m-CDS-1 (1.01 x 10(7)CFU/g dry soil) could degrade both 10.71 mg/kg methyl parathion and 1.29 mg/kg carbofuran in 30 days. m-CDS-1 declined quickly with time, and could not be detected anymore in 30 days. Release of m-CDS-1 would not change the number of the cultivable microorganisms notably. The similarities of PCR-DGGE profiles between the pesticides applied treatments and the controls in 4, 11 and 30 days were 17.16 %, 49.81 % and 75.01 %, and the similarities between the m-CDS-1 released treatments and controls were 49.57 %, 38.3 % and 83.3 %, respectively. In 60 days, DGGE profiles of all treatments and controls had high similarities.

m-CDS-1 could degrade both pesticides remarkably in the field, and would not be the predominant population, and would not affect the community structure of soil microorganisms in the long term.