Chemical Modification of the Glycerol Dehydrogenase by Divalent Metal Ions

甘油脱氢酶(gdH)可以催化甘油生成二羟基丙酮.为了进一步探索gdH的活性结构中心,提高gdH的活性,用Mg2+、Mn2+、bA2+、CA2+、zn2+、Cu2+、Sr2+、nI2+、Cd2+和CO2+等10种金属离子对gdH进行活性中心金属离子置换修饰,筛选出具有修饰效果的离子为Mg2+、Mn2+和bA2+,修饰后其最大酶活力分别是初始酶活力的3.4,2.0和4.7倍.通过均匀设计对3种金属离子的修饰条件进行了优化,优化后测定的酶活力分别是未修饰gdH酶活力值3.17 u/Ml的14.9,11.3和12.4倍,极大地提高了gdH的酶活力.Glycerol dehydrogenase(GDH) can catalyze the interconversion of glycerol and dihydroxyacetone.In order to improve the activity and explore the active central site of GDH,10 kinds of metal ions such as Mg2+,Mn2+,Ba2+,Ca2+,Zn2+,Cu2+,Sr2+,Ni2+,Cd2+and Co2+ were used to do chemical modification on GDH.The results approved that the activity of GDH was significantly increased by Mg2+,Mn2+ and Ba2+ while the special activity of GDH was 3.4,2.0 and 4.7 folds respectively of the control′s after modification.Meanwhile,the activity effects of Mg2+,Ba2+ and Mn2+ on GDH showed that the GDH was successfully modificated by Mg2+,Ba2+ and Mn2+.The modificated condition was optimized with the uniform design.Compared to the original activity of GDH 3.17 U/mL,the activity of GDH modified by Mg2+,Ba2+ and Mn2+ was improved separately as 14.9,11.3 and 12.4 folds after optimization.国家高技术研究发展计划(863)项目(2006AA020103);福建省高校产学合作科技重大项目(2010H6023

应用流式细胞术鉴定死活结核分枝杆菌的实验研究

【目的】探讨碘化丙锭（PI）和6-羧基荧光素二乙酸酯（6-cFDA）鉴别死、活结核分枝杆菌的性能，为应用流式细胞术定量检测与分析结核分枝杆菌药物敏感性和异质性耐药方法的创建提供基础性实验依据。【方法】应用PI和6-cFDA分别对10株1麦氏浊度结核分枝杆菌纯培养活菌悬液和其相应的1麦氏浊度85℃加热30min的死菌悬液进行染色，应用流式细胞术检测其平均荧光强度（MFI），依据受试者工作特征曲线（ROC）确定区分死菌与活菌的MFI界值，然后对另外10株活菌悬液和10株死菌悬液进行相同实验，利用前述MFI界值进行细菌死活判定。【结果】①在确定MFI界值实验中：10份死菌悬液样本PI染色的MFI值呈非正态分布，其中位值为2459，10份活菌悬液样本PI染色的MFI值呈正态分布，其均值为426±180，PI染色鉴定死菌的MFI界值为1329；10份死、活菌悬液样本6-cFDA染色的MFI值均呈正态分布，其均值分别为49±4和7144±4512，6-cFDA染色鉴定活菌的MFI界值为1021。②应用PI染色鉴定死菌的MFI界值和6-cFDA染色鉴定活菌的MFI界值检测另外10株活菌悬液和10株死菌悬液，其准确度分别为95%和100%，灵敏度分别为1.00和1.00，特异度分别为0.90和1.00，Yonde指数分别为0.90和1.00，阳性预测值分别为0.91和1.00，阴性预测值分别为1.00和1.00。【结论】PI染色能够良好鉴定结核分枝杆菌死菌、6-cFDA染色能够良好鉴定结核分枝杆菌活菌，基于PI、6-cFDA染色鉴定结核分枝杆菌活性将具有广阔的应用前景

Pesticide Degrading Microorganisms and Mechanism in Soil

化学农药在土壤中残留造成的环境污染和给人类健康带来的危害日益严重,土壤微生物在土壤残留农药降解中起着关键作用,利用微生物来降解农药可以保障土壤的健康发展。本文从土壤残留农药的种类、降解农药的微生物类群、微生物降解农药的机理、微生物降解的影响因素等方面进行了综述,并且对土壤农药微生物降解的研究趋势提出了自己的观点。Pesticides have played an important role on the aspects of preventing crops from disaster of diseases,pests,weeds,and so on.However, the subsequent problem was that pesticide residue brought serious harm to the health of human beings and environment.In order to change the status quo,a mass of scientific researches have been made by scientists at present,including degrading pesticide residue by microorganism.Pesticides in soil,degrading microorganisms of pesticide in nature,degradation mechanism of pesticide and factors affecting on pesticide's degradation were reviewed in this paper.At the same time,own opinions on pesticide biodegradation were put forward.国家支撑计划项目课题(2008BADA7B09); 国家自然科学基金(40771116