Development of a bioavailable Hg(II) sensing system based on MerR-regulated visual pigment biosynthesis.

Engineered microorganisms have proven to be a highly effective and robust tool to specifically detect heavy metals in the environment. In this study, a highly specific pigment-based whole-cell biosensor has been investigated for the detection of bioavailable Hg(II) based on an artificial heavy metal resistance operon. The basic working principle of biosensors is based on the violacein biosynthesis under the control of mercury resistance (mer) promoter and mercury resistance regulator (MerR).

[Microstructure and spectral property of Er3+ doped transparent oxyfluoride glass ceramics with high fluorine contents].

The microstructure and spectral properties of Er3+ doped transparent oxyfluoride glass ceramics with high fluorine content were reported. Two samples with the same initial contents (50SiO2-45PbF2-5PbO-1ErF3) were prepared under the different preparation parameters. The final fluorine contents were detected by a fluoride ion selective electrode.

[Nitrogen flow in farming-feeding system and its environmental impact in China].

By applying nitrogen flow model for farming-feeding system (NFM-FFS) which integrates soil full nitrogen balance model with inventory analysis for agricultural pollution, nitrogen flow in China farming-feeding systems and its environmental impact are analyzed. In 2003, although surface nitrogen surpluses, nitrogen deficit in agricultural soil system in China is estimated to be 623.9 x 10(4) t, and 13.

[Inventory of regional surface nutrient balance and policy recommendations in China].

By applying OECD surface soil nitrogen balance methodology, the framework, methodology and database for nutrient balance budget in China are established to evaluate the impact of nutrient balance on agricultural production and water environment. Results show that nitrogen and phosphorus surplus in China are 640 x 10(4) t and 98 x 10(4) t respectively, and nitrogen and phosphorus surplus intensity in China are 16.56 kg/hm2 and 2.