Abstract:

The natural  red soil was used  in  this study as a  research object, and  the  influence of semiconductor photocatalysis
of  iron-bearing minerals on microbial community was analyzed. Using  the polymerase chain  reaction/degeneration gradient gel
electrophoresis  (PCR-DGGE),  the microbial community  from  the original  red soil samples under different  light conditions was
investigated after being disposed with exogenous electrons supplement. Principal component analysis  (PCA) of DGGE banding
patterns indicated that the difference of the microbial community structure in two soil samples was due to different original light
environments.  In  the  red soil with strong  light, no significant change of  the microorganism community structure was observed
by processing with exogenous electrons; while in the original environment with weak light, the structure of microbial community
was significantly affected by  the exogenous electrons. The different response of microbial community structure  to  the exogenous
electrons may be attributed to the photoinduced electrons generated by the semiconducting mineral photocatalysis in the primitive
strong  irradiation environment, which continued  to affect  the surrounding microbial communities; while photoinduced electrons
were inadequate in the weak irradiation environment.

Key words: red soil, microbial community, PCR-DGGE, exogenous electrons, semiconductor photocatalysis