[Movement and transformation of heavy metals in water-sediment in water-level-fluctuating zone of Three Gorges Reservoir Area].

According to the off-season regulation model for Three Gorges Reservoir, the characteristic of movement and transformation of Cu, Pb, Cd and Cr in sediment of water-level-fluctuating zone of Three Gorge Reservoir Area was investigated. The results indicated that the chemical fraction composition characteristics of heavy metals are different. Cu mainly existed in organic/sulphidic fraction and residual fraction; Pb mainly existed in carbonates, Fe-Mn oxides and residual fraction; Cd mainly existed in carbonates and Fe-Mn oxides fraction; Cr mainly existed in residual fraction.

[Preliminary study on bacterial culture through near-natural pure culture technique].

Based on the ecological features of mutual benefits of different microbes in natural environment, near-natural pure culture technique which was an improvement of conventional pure culture method had been put forward. The key point of this new method was to make hole petri dishes covered with millipore membranes. When these covered dishes being used to culture microorganisms, it could provide incubated microbes active materials from native environment, maintain free communicating with outside microbes, and improve their recovery and culturability of some bacteria.

[Ecological interpretation and related strategies for low culturability of microorganisms].

Pure culture technique has been a fundamental method since its invention in microbiology, but its isolated and monotonous environment contradicts microbial diversity and cooperation relationship in natural environment. And this contradiction directly results in the uncultivability of some microbes in media. From ecological viewpoint, the recovery barriers of natural microbes mainly include the crash of cooperation in natural environment, the great change of nutrient in new environment and the loss of native niche.