Comparative Proteomics Study On Comamonas Testosteroni S44under The Heavy Metal Antimony Pressure

Antimony (Sb) as one of the most important heavy metal elements widely exists in the soil and aquatic ecosystems. Although antimony has long been used to treat leishmaniasis, the damage caused by antimony for human and environmental pollution has not been ignored. As the world most abundant antimony resources and the biggest antimony demand country, the antimony pollution of China is particularly serious. Presently, some microorganisms has been reported to have the antimony resistant and oxidation, but there are very few studies on the mechanism of resistance and oxidatioa C. testosteroni S44is found by our lab, which could resist and oxidate the antimony. Strain S44could oxidize50μmol/L Sb (III) in3days. Microbial proteomics is to study and identify microbial metabolism related proteins. The characteristics of proteomics determine that it would be more profound than other traditional methods in explanation of the mechanism of the diversity of micro-organisms to adapt to environmental stress conditions. This experiment by using the microbial proteomics technology research C. testosteroni S44metabolic activity under the stress of heavy metal antimony.In the proteomics research of C. testosteroni S44antimony resistance mechanisms, by anlysising the2-DE gels,87proteins were selected for MS, and successfully identified57proteins(except the failed and different points for one protein), According to the KEGG functional classification:Genetic information processing25%, Environmental information processing12%, Metabolism59%, Unclassified4%. Through the analysis of results, we found that:(1) the abundance of proteins increased covered63.2%of total identified;(2) the changes of Antioxidant and stress proteins expression was in order to increase the resistance of antimony and reduction of damage caused by Sb;(3) most of proteins and enzymes involved in glycometabolism were up-regulation;(4) translation and amino acid metabolism level generally increased;(5) Enhanced fatty acid metabolism and changes in expression levels of PHB related enzymes indicated that intracellular energy storage and release all increased;(6) Changes in expression level of energy relative protein demoistrated that intracellular substrate-level phosphorylation increased but oxidative phosphorylation decreased.In one word, in the present of Sb (III), obvious changes have taken place in the level of intracellular metabolism. All these changes provide the basis for the cell resistance to heavy metal Sb stress. Proteomics research method was first used to study on the heavy metal antimony metabolism of microorganism.