Enzyme Preparation for Degrading Organophosphorus Pesticides

The research project "Enzyme Preparation for Degrading Organophosphorus Pesticides" which was completed by the Biotechnology Research Institute of Chinese Academy of Agriculture, recently passed the appraisal of the Ministry of Agriculture of China. It will bring about important positive effect on China’s food safety and biological environmental protection.   From the polluted earth, researchers firstly gained a tree of bacterium that is able to degrade many kinds of organophosphorus pesticides. Then the coding genes of this bacterium were duplicated and cloned, there the molecule were modified. The final preparation contained 6 gram per liter of degrading enzyme for degrading organophosphorus with an enzyme activity of 16 000 U/mL in the fermentation solution, representing the current highest contents available in the world.    The research result shows that the modified Pichia pastoris yeast that represents the degrading enzyme has great safety, no record in medicine, and does not secrete any poisonous substances in the cultivation process. By making use of secreting representing carrier, the degrading enzyme for organophosphorus can be successfully secreted out of cell, simplifying the after treatment process and reducing the cost.    The researching team has confirmed a stable fermentation technology that manufactures degrading enzyme for organophosphorus through making use of gene engineering yeast bacterium. Concerned technological conditions are based on the pilot level that is carried out in a 3-tons fermentation tank. It is easy to ferment with sufficient and common raw materials. Technological indexes are also vigorous. All the features designed a firm base for its commercial production of the degrading enzyme.