The widespread contamination by mycotoxins,especially zearalenone and aflatoxins,in crops and their by-products has caused severe undesirable effects on human health and commercial trade.Researchers had screened out m...The widespread contamination by mycotoxins,especially zearalenone and aflatoxins,in crops and their by-products has caused severe undesirable effects on human health and commercial trade.Researchers had screened out microorganisms from various media for degrading zearalenone and aflatoxins,and the results of a lot of studies showed that enzymes derived from microbial strains play a key role in degrading mycotoxins.Genetic engineering technology had been applied to improve the heterologously expressed degrading enzymes in several mature microbial hosts such as Escherichia coli and Pichia pastoris.The separated and purified recombinant enzyme had high activity in degrading mycotoxins in vitro.This review summarized the types of mycotoxins-degrading microorganisms and enzymes,and the progress on synthesis of heterologously expressed degrading enzymes by genetic engineering technology as well as related researches on improving the effect of degrading enzymes.We also prospected the future development in the study of using recombinant enzymes formed by genetic engineering technology to realize the simultaneous degradation of multiple mycotoxins in crops.展开更多
Coalbed gases (CBG) in Enhong syncline are characterized by high concentration of C2+ (C2-5 ), with the highest content of ethane over 30%. However, the concentrations of C2+ are not evenly distributed in the syncline...Coalbed gases (CBG) in Enhong syncline are characterized by high concentration of C2+ (C2-5 ), with the highest content of ethane over 30%. However, the concentrations of C2+ are not evenly distributed in the syncline. Based on the analysis of δ13C1 , δ13C2 , δ13C3 , δ13CO2 , δDCH4 of CBG and their origin diagrams in the normal and abnormal areas, this research shows that gases in both areas are thermogenic gases and the reason for the uneven distribution of C2+ is that the microbial degradation action on gases is stronger in the normal area than in the abnormal area. The secondary biologic gases in the normal area are mainly characterized by that the carbon isotopes become obviously lighter in methane and become heavier in ethane, whereas the molecular and isotopic compositions of CO2 change little. These features indicate that the secondary biologic gases are mainly generated by the microbial degradation of C2+ , not generated by the reduction of CO2 . The degradation process is selective to make the residual ethane being enriched in 13C and the generated methane rich in 12C.展开更多
基金supported by Program for Innovative Research Team(in Science&Technology)in University of Henan Province(No.20IRTSTHN023)supported by Key research and development and promotion special project of Science and Technology Department of Henan Province,China(No.192102310254)。
文摘The widespread contamination by mycotoxins,especially zearalenone and aflatoxins,in crops and their by-products has caused severe undesirable effects on human health and commercial trade.Researchers had screened out microorganisms from various media for degrading zearalenone and aflatoxins,and the results of a lot of studies showed that enzymes derived from microbial strains play a key role in degrading mycotoxins.Genetic engineering technology had been applied to improve the heterologously expressed degrading enzymes in several mature microbial hosts such as Escherichia coli and Pichia pastoris.The separated and purified recombinant enzyme had high activity in degrading mycotoxins in vitro.This review summarized the types of mycotoxins-degrading microorganisms and enzymes,and the progress on synthesis of heterologously expressed degrading enzymes by genetic engineering technology as well as related researches on improving the effect of degrading enzymes.We also prospected the future development in the study of using recombinant enzymes formed by genetic engineering technology to realize the simultaneous degradation of multiple mycotoxins in crops.
基金supported by the Key Program of the National Natural Science Foundation of China (No. 40730422)the Key Special Project of the National Science and Technology of China (No.2011ZX05034)the Fundamental Research Funds for the Central Universities of China (No. 2010QNA51)
文摘Coalbed gases (CBG) in Enhong syncline are characterized by high concentration of C2+ (C2-5 ), with the highest content of ethane over 30%. However, the concentrations of C2+ are not evenly distributed in the syncline. Based on the analysis of δ13C1 , δ13C2 , δ13C3 , δ13CO2 , δDCH4 of CBG and their origin diagrams in the normal and abnormal areas, this research shows that gases in both areas are thermogenic gases and the reason for the uneven distribution of C2+ is that the microbial degradation action on gases is stronger in the normal area than in the abnormal area. The secondary biologic gases in the normal area are mainly characterized by that the carbon isotopes become obviously lighter in methane and become heavier in ethane, whereas the molecular and isotopic compositions of CO2 change little. These features indicate that the secondary biologic gases are mainly generated by the microbial degradation of C2+ , not generated by the reduction of CO2 . The degradation process is selective to make the residual ethane being enriched in 13C and the generated methane rich in 12C.
