Studies On Screening And Purification Of Phytoesterase And Its Sensitivities To Pesticide Residues

Pesticides play a very important role in agricultural production, but most of the organophosphate and carbamate pesticides have acute toxicity to human and animals, and meanwhile they often have high residues in farm produce, thereby leading the residues sometimes go beyond the limits, which have bad effect on the food safety as well as farm products trade. Therefore, research and development a fast and convenience technique for inspection pesticide residues are urgent demands for our country today.At the present time, many rapid detection methods have developed for determining pesticide residues, in which the enzyme-inhibition methods have payed more attention for its sensitive, rapid, simple and convenient. Due to it's similar sensitivity of cholinesterase and hydrolyze esterase, easier gaining and abundant source, phytoesterase can reach the popular and marketable desire of pesticides inspection. But there are few studies on the abstraction and purification of phytoesterase. Based on the screening of enzyme material from some plant seeds, the abstraction and purification of phytoesterase, the enzyme character, and the sensitivities as well as the LDCs of phytoesterase from soybeans to 19 organophosphate pesticides and 8 carbamate pesticides were studied in this paper. The results are as follows:1. Through evaluated the total enzyme activity and the sensitivity to pesticides of wheat, soybean, corn, rice and barley, soybean was selected as the best phytoesterase source. The LDCs of omethoate, dichlorvos, acephatemet, parathion and monocrotophos were 0.1, 0.05 , 0.05 , 0.0625 and 0.05mg/L respectively using phytoesterase from soybean. So, we can conclude that the phytoesterase from soybean can fulfill the detection of organophosphate pesticides.2. The technical process on purification of phytoesterase from soybeans as follows: soybean flour was surged for 30 min with phosphate buffer(0.3mol/L, pH 7.0), then, dipped it at 4°C for more than 12 hours and filtrated by gauze. Next, centrifugalize the filtrate at 6000rpm to 1000rpm by differential centrifugation. The supernatant fluid was...