Five compounds were isolated from the ether-soluble fraction of the spores of Gano- derma lucidum.On the basis of their chemical properties and spectral data(MS,UV,IR,~1H and ^(13)CNMR),they were identified as 3,7,11,...Five compounds were isolated from the ether-soluble fraction of the spores of Gano- derma lucidum.On the basis of their chemical properties and spectral data(MS,UV,IR,~1H and ^(13)CNMR),they were identified as 3,7,11,12,15,23-hexaoxo-5α-lanosta-8-en-26-oic acid(Ⅰ),gano- deric acid B(Ⅱ),C(Ⅲ),D(Ⅳ)and ganodermanontriol(Ⅴ).Compound Ⅰ is a new natural product, named ganosporeric acid A.Compounds Ⅱ,Ⅲ,Ⅳ and Ⅴ are known compounds and were obtained for the first time from the spores of Ganoderma lucidum.Pharmacological experiments showed that ganosporeric acid A has an activity for lowering the levels GPT in mice with liver injury by CCl_4 and GaNI and exhibits heptoprotective effects.展开更多
B.Subtilis expression plasmids generally require a stringent Shine Dalgarno Sequence(SDS). Site directed mutagenesis was explored to change the Shine Dalgarno Sequence from AAAAATGGGG (mutant type) to AAAAAGGGGG (...B.Subtilis expression plasmids generally require a stringent Shine Dalgarno Sequence(SDS). Site directed mutagenesis was explored to change the Shine Dalgarno Sequence from AAAAATGGGG (mutant type) to AAAAAGGGGG (wild type) in recombinant plasmid PSM604. The single base substitution made the plasmid with wild SDS unstable in structure and segregation. The interaction of SDS with subtilisin leader sequence of PSM604 might be responsible for the instability of plasmid.展开更多
Track theory rested on the foundation of the radial distribution of dose from δ rays as the central contribution of atomic physics to heavy ion radiobiology.Here,a new calculation of the radial distribution of dose i...Track theory rested on the foundation of the radial distribution of dose from δ rays as the central contribution of atomic physics to heavy ion radiobiology.Here,a new calculation of the radial distribution of dose is applied, in which the classical angular distribution of dose of delta rays and a logarithmic polynomial representation of the electron range-energy relation are used,to form the basis of the present thindown calculation.Calculations of inactivation cross sections for heavy ions in the track width regime displaying thindown for E.Colt B/r and Bs-1,and for Bacillus Subtilus are straightforward for these are 1-hit detectors,Calculations for V-79 hamster cells are more complex.They follow the original development of this model for eucaryotic cells,and make use of the cross sections calculated for hypothetical internal targets which are then asserted to be proportional to the measured cellular inactivation cross sections.The results are in reasonable agreement with experimental data.展开更多
枯草杆菌芽孢是极难被杀灭的细菌之一,为探究山梨酸钾与压力辅助热杀菌(pressure assisted thermal sterilization,PATS)对枯草杆菌芽孢的联合作用效果,该研究以OD600值(optical density at 600 nm)、OD_(260)值(optical density at 260...枯草杆菌芽孢是极难被杀灭的细菌之一,为探究山梨酸钾与压力辅助热杀菌(pressure assisted thermal sterilization,PATS)对枯草杆菌芽孢的联合作用效果,该研究以OD600值(optical density at 600 nm)、OD_(260)值(optical density at 260 nm)、OD_(280)值(optical density at 280 nm)、2,6-吡啶二羧酸释放率表征芽孢内容物的释放情况,扫描电镜、流式细胞术、傅里叶红外光谱仪、激光粒度仪检测芽孢结构变化情况。结果表明,山梨酸钾强化了PATS的杀菌效果,200 MPa-75℃处理杀灭了2.63 lg CFU/mL芽孢,添加2 g/L山梨酸钾后,杀灭了3.24 lg CFU/mL芽孢。较单独PATS处理,添加山梨酸钾后,促进了芽孢内容物的释放,内膜通透性增加,芽孢粒径显著减小,内膜、细胞壁等结构受损程度加剧。同时,Na^(+)/K^(+)-ATPase活力显著降低,膜电位平衡被破坏,基本生理代谢功能紊乱。总之,PATS结合山梨酸钾对枯草芽孢杆菌芽孢有协同杀菌作用,且随着山梨酸钾添加量或温度的升高而增强,有利于促进该技术在食品杀菌中的应用。展开更多
[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomat...[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomato stems by UV mutagenesis for two consecutive times,then genetic stability as well as physiological and biochemical properties of mutant strains were studied.[Result] The antibacterial activity of all the three mutant strains F303,F304 and F305 was higher than that of B74 strain.After subculture of 10 successive generations,the antibacterial activity of all the three mutant strains for the pathogens of watermelon fusarium wilt decreased,but the antibacterial activity of F305 strain decreased the least,indicating its best genetic stability among the tested strains.The antibacterial circle diameter of F305 strain was 5 mm larger than that of wild strain B47 under the same condition.The mutant strain F305 was in logarithmic growth phase within 36 h and in stationary phase within 36-96 h,while its optimum growth temperature was 35 ℃.F305 strain could grow in sodium salt with the concentration of 1%-10%,but it grew best at the concentration of 1%.Physiological and biochemical responses of F305 strain were in accordance with those of wild strain B47.[Conclusion] This study lays the foundation for the factorial production of antagonistic substance by B47 strain and new methods of preventing from the pathogens watermelon fusarium wilt.展开更多
基金This project was supported by National Natural Science Foundation of China
文摘Five compounds were isolated from the ether-soluble fraction of the spores of Gano- derma lucidum.On the basis of their chemical properties and spectral data(MS,UV,IR,~1H and ^(13)CNMR),they were identified as 3,7,11,12,15,23-hexaoxo-5α-lanosta-8-en-26-oic acid(Ⅰ),gano- deric acid B(Ⅱ),C(Ⅲ),D(Ⅳ)and ganodermanontriol(Ⅴ).Compound Ⅰ is a new natural product, named ganosporeric acid A.Compounds Ⅱ,Ⅲ,Ⅳ and Ⅴ are known compounds and were obtained for the first time from the spores of Ganoderma lucidum.Pharmacological experiments showed that ganosporeric acid A has an activity for lowering the levels GPT in mice with liver injury by CCl_4 and GaNI and exhibits heptoprotective effects.
文摘B.Subtilis expression plasmids generally require a stringent Shine Dalgarno Sequence(SDS). Site directed mutagenesis was explored to change the Shine Dalgarno Sequence from AAAAATGGGG (mutant type) to AAAAAGGGGG (wild type) in recombinant plasmid PSM604. The single base substitution made the plasmid with wild SDS unstable in structure and segregation. The interaction of SDS with subtilisin leader sequence of PSM604 might be responsible for the instability of plasmid.
文摘Track theory rested on the foundation of the radial distribution of dose from δ rays as the central contribution of atomic physics to heavy ion radiobiology.Here,a new calculation of the radial distribution of dose is applied, in which the classical angular distribution of dose of delta rays and a logarithmic polynomial representation of the electron range-energy relation are used,to form the basis of the present thindown calculation.Calculations of inactivation cross sections for heavy ions in the track width regime displaying thindown for E.Colt B/r and Bs-1,and for Bacillus Subtilus are straightforward for these are 1-hit detectors,Calculations for V-79 hamster cells are more complex.They follow the original development of this model for eucaryotic cells,and make use of the cross sections calculated for hypothetical internal targets which are then asserted to be proportional to the measured cellular inactivation cross sections.The results are in reasonable agreement with experimental data.
文摘枯草杆菌芽孢是极难被杀灭的细菌之一,为探究山梨酸钾与压力辅助热杀菌(pressure assisted thermal sterilization,PATS)对枯草杆菌芽孢的联合作用效果,该研究以OD600值(optical density at 600 nm)、OD_(260)值(optical density at 260 nm)、OD_(280)值(optical density at 280 nm)、2,6-吡啶二羧酸释放率表征芽孢内容物的释放情况,扫描电镜、流式细胞术、傅里叶红外光谱仪、激光粒度仪检测芽孢结构变化情况。结果表明,山梨酸钾强化了PATS的杀菌效果,200 MPa-75℃处理杀灭了2.63 lg CFU/mL芽孢,添加2 g/L山梨酸钾后,杀灭了3.24 lg CFU/mL芽孢。较单独PATS处理,添加山梨酸钾后,促进了芽孢内容物的释放,内膜通透性增加,芽孢粒径显著减小,内膜、细胞壁等结构受损程度加剧。同时,Na^(+)/K^(+)-ATPase活力显著降低,膜电位平衡被破坏,基本生理代谢功能紊乱。总之,PATS结合山梨酸钾对枯草芽孢杆菌芽孢有协同杀菌作用,且随着山梨酸钾添加量或温度的升高而增强,有利于促进该技术在食品杀菌中的应用。
基金Supported by the Fund of Science and Technology in GuangXi Zhuang Autonomous Region(0009018)~~
文摘[Objective] The aim of this study was to breed new strains which have higher inhibitory effects on the pathogens of watermelon fusarium wilt.[Method] The endophytic Bacillus subtilis B47 strain was obtained from tomato stems by UV mutagenesis for two consecutive times,then genetic stability as well as physiological and biochemical properties of mutant strains were studied.[Result] The antibacterial activity of all the three mutant strains F303,F304 and F305 was higher than that of B74 strain.After subculture of 10 successive generations,the antibacterial activity of all the three mutant strains for the pathogens of watermelon fusarium wilt decreased,but the antibacterial activity of F305 strain decreased the least,indicating its best genetic stability among the tested strains.The antibacterial circle diameter of F305 strain was 5 mm larger than that of wild strain B47 under the same condition.The mutant strain F305 was in logarithmic growth phase within 36 h and in stationary phase within 36-96 h,while its optimum growth temperature was 35 ℃.F305 strain could grow in sodium salt with the concentration of 1%-10%,but it grew best at the concentration of 1%.Physiological and biochemical responses of F305 strain were in accordance with those of wild strain B47.[Conclusion] This study lays the foundation for the factorial production of antagonistic substance by B47 strain and new methods of preventing from the pathogens watermelon fusarium wilt.
