外源芘的添加对水稻土微生物群落多样性的影响

In this paper the effect of exogenous pyrene on structural and genetic diversities of microbial community in a paddy soil was studied using phospholipid fatty acids (PLFA) analysis and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). PLFA analysis showed that bacteria are the predominant microbial populations in soil microbial communities. During the incubation time of 1 to 15 days, the total PLFA contant was higher in pyrene-spiked soils than the unspiked control, while the results was opposite after 30 days incubation. At the end of incubation experiment, the spiking of pyrene increased fatty acids contents of fungus, actinomycetes and gram-negative bacteria, but decreased fatty acids contents of gram-positive bacteria. PCR-DGGE analysis showed that the spiking of pyrene altered the genetic diversity of soil bacterial community when compared with the control. Genetic diversity index was lowest at the incubation time of the fifteenth day, while that was highest at the incubation time of the thirtieth day. Variation of the diversity index might be related to the degradation of pyrene in the spiked soils.