Deoxynivalenol(DON),the most common mycotoxin in the world,poses serious health hazards to both humans and animals and causes significant economic losses to the food and feed industry.An intriguing method for DON deto...Deoxynivalenol(DON),the most common mycotoxin in the world,poses serious health hazards to both humans and animals and causes significant economic losses to the food and feed industry.An intriguing method for DON detoxification involves enzymatic cascade catalysis by pyrroloquinoline quinone-dependent alcohol dehydrogenase(DADH)and aldo-keto reductase(AKR13B3).However,the poor catalytic activity of AKR13B3 has limited its usefulness.Here,structure-guided steric hindrance engineering,computer-assisted protein engineering,and combinatorial mutagenesis were carried out to increase the catalytic efficiency of AKR13B3.The best mutant in this project was M28S/S65V,which outperformed wild-type AKR13B3 in terms of catalytic efficiency(kcat/Km)and specific activity by factors of 44.07 and 41.65,respectively.Kinetic parameter determination revealed that the enhanced catalytic efficiency of M28S/S65V toward 3-keto-DON was attributed to the decreased Km and increased kcat values.Moreover,the engineered enzyme was applied to degrade DON in contaminated corn steep liquor,for a 90.62%removal rate.Structure-based computational analysis provided insights into the enhanced catalytic efficiency of M28S/S65V,which was attributed to the enlarged substrate-binding pocket and reshaped pocket with a favorable hydrophilic attack distance.The results provide a reference for improving the catalytic activity of an enzyme toward non-native bulky substrates and pave the way for the development of enzymes as detoxification agents to mitigate DON in the food and feed industry.展开更多
In this study, four phosphorus-inefficient soybean genotypes （1903, 1305, D17 and D18） and four phosphorus-efficient soybean genotypes （D31, D34, D37 and D38 ） were selected as experimental materials for soil cult...In this study, four phosphorus-inefficient soybean genotypes （1903, 1305, D17 and D18） and four phosphorus-efficient soybean genotypes （D31, D34, D37 and D38 ） were selected as experimental materials for soil culture experiment under high and low phosphorus treatments, to investigate the grain yield, phosphorus content, phosphorus uptake and the relationship between phosphorus utilization efficiency and phosphorus efficiency of soybean genotypes with different phos- phorus efficiency in mature period. According to the experimental results, under low phosphorus treatment, four phosphorus-efficient soybean genotypes exhibited significantly high phosphorus uptake in mature period, especially for D31 and D37; however, three phosphorus-efficient genotypes showed no advantages in adapta- bility of phosphorus utilization efficiency, while only I）31 exhibited high phosphorus utilization and absorption capacity. Correlation analysis and path analysis showed that phosphorus deficiency of soybean was mainly detemained by phosphorus absorption capacity, and phosphorus deficiency under （-P） treatment was sig- nificandy higher than （ ＋ P） treatment. Phosphorus uptake and phosphorus utilization efficiency posed great direct effects on phosphorus efficiency, and phosphorus uptake exhibited a greater contribution ; in addition, these two factors both posed small indirect effects. In mature period at reproductive growth stage, phosphorus absorption efficiency （phosphorus uptake） was the main variation source of phosphorus efficiency of various soybean genotypes in mature period. Therefore, strong phosphorus uptake and accumulation capacity of phosphorus-efficient soybean genotypes in mature period is an important nutrition foundation for the information of high grain yield.展开更多
Bacillomycin D is a nonribosomal peptide produced by Bacillus amyloliquefaciens fmbJ.In this study,the biosynthesis of bacillomycin D was mediated by replacing the intermodule donor,acceptor,and communication-mediatin...Bacillomycin D is a nonribosomal peptide produced by Bacillus amyloliquefaciens fmbJ.In this study,the biosynthesis of bacillomycin D was mediated by replacing the intermodule donor,acceptor,and communication-mediating(COM)domain pairs and introducing the COM domain between the surfactin subunits.Both the homologous donor and the COM domain pair replacement strains eliminated the selective barrier of the original COM domain pair to a certain extent,resulting in a more flexible hybrid biosynthesis system that provides simultaneous biosynthesis of different lipopeptide products.The synthesis of bacillomycin D in the homologous acceptor replacement strains was barely affected.The COM domains between the surfactin subunits cannot establish efficient communication between the bacillomycin D modules.In conclusion,the COM domains compatibility between the bacillomycin D modules are extremely strong,and the conserved amino acid residues in the acceptor domain are an important part of module–module interactions and efficient communication during bacillomycin D synthesis.展开更多
基金funded by the National Natural Science Foundation of China(32272267)Jiangsu Provincial Frontier Technology Research and Development Program(BF2024073).
文摘Deoxynivalenol(DON),the most common mycotoxin in the world,poses serious health hazards to both humans and animals and causes significant economic losses to the food and feed industry.An intriguing method for DON detoxification involves enzymatic cascade catalysis by pyrroloquinoline quinone-dependent alcohol dehydrogenase(DADH)and aldo-keto reductase(AKR13B3).However,the poor catalytic activity of AKR13B3 has limited its usefulness.Here,structure-guided steric hindrance engineering,computer-assisted protein engineering,and combinatorial mutagenesis were carried out to increase the catalytic efficiency of AKR13B3.The best mutant in this project was M28S/S65V,which outperformed wild-type AKR13B3 in terms of catalytic efficiency(kcat/Km)and specific activity by factors of 44.07 and 41.65,respectively.Kinetic parameter determination revealed that the enhanced catalytic efficiency of M28S/S65V toward 3-keto-DON was attributed to the decreased Km and increased kcat values.Moreover,the engineered enzyme was applied to degrade DON in contaminated corn steep liquor,for a 90.62%removal rate.Structure-based computational analysis provided insights into the enhanced catalytic efficiency of M28S/S65V,which was attributed to the enlarged substrate-binding pocket and reshaped pocket with a favorable hydrophilic attack distance.The results provide a reference for improving the catalytic activity of an enzyme toward non-native bulky substrates and pave the way for the development of enzymes as detoxification agents to mitigate DON in the food and feed industry.
基金Supported by Doctoral Scientific Research Start-up Project of Mudanjiang Normal University(MSB200912)Provincial Key Pre-research Project of Mudanjiang Normal University(SY2014010)Teaching Reform Project of Mudanjiang Normal University(2013JGZX0074)
文摘In this study, four phosphorus-inefficient soybean genotypes （1903, 1305, D17 and D18） and four phosphorus-efficient soybean genotypes （D31, D34, D37 and D38 ） were selected as experimental materials for soil culture experiment under high and low phosphorus treatments, to investigate the grain yield, phosphorus content, phosphorus uptake and the relationship between phosphorus utilization efficiency and phosphorus efficiency of soybean genotypes with different phos- phorus efficiency in mature period. According to the experimental results, under low phosphorus treatment, four phosphorus-efficient soybean genotypes exhibited significantly high phosphorus uptake in mature period, especially for D31 and D37; however, three phosphorus-efficient genotypes showed no advantages in adapta- bility of phosphorus utilization efficiency, while only I）31 exhibited high phosphorus utilization and absorption capacity. Correlation analysis and path analysis showed that phosphorus deficiency of soybean was mainly detemained by phosphorus absorption capacity, and phosphorus deficiency under （-P） treatment was sig- nificandy higher than （ ＋ P） treatment. Phosphorus uptake and phosphorus utilization efficiency posed great direct effects on phosphorus efficiency, and phosphorus uptake exhibited a greater contribution ; in addition, these two factors both posed small indirect effects. In mature period at reproductive growth stage, phosphorus absorption efficiency （phosphorus uptake） was the main variation source of phosphorus efficiency of various soybean genotypes in mature period. Therefore, strong phosphorus uptake and accumulation capacity of phosphorus-efficient soybean genotypes in mature period is an important nutrition foundation for the information of high grain yield.
基金supported by grants from the National Natural Science Foundation of China(Grant No.31972174).
文摘Bacillomycin D is a nonribosomal peptide produced by Bacillus amyloliquefaciens fmbJ.In this study,the biosynthesis of bacillomycin D was mediated by replacing the intermodule donor,acceptor,and communication-mediating(COM)domain pairs and introducing the COM domain between the surfactin subunits.Both the homologous donor and the COM domain pair replacement strains eliminated the selective barrier of the original COM domain pair to a certain extent,resulting in a more flexible hybrid biosynthesis system that provides simultaneous biosynthesis of different lipopeptide products.The synthesis of bacillomycin D in the homologous acceptor replacement strains was barely affected.The COM domains between the surfactin subunits cannot establish efficient communication between the bacillomycin D modules.In conclusion,the COM domains compatibility between the bacillomycin D modules are extremely strong,and the conserved amino acid residues in the acceptor domain are an important part of module–module interactions and efficient communication during bacillomycin D synthesis.
