目的从红树林根际淤泥中分离鉴定放线菌并进行多样性分析及抗菌活性研究,为新抗生素的发现提供药用放线菌资源。方法用6种分离培养基,利用涂布平板法分离放线菌;通过PCR扩增获得菌株16S r RNA基因并进行同源性比对,分析放线菌多样性;发...目的从红树林根际淤泥中分离鉴定放线菌并进行多样性分析及抗菌活性研究,为新抗生素的发现提供药用放线菌资源。方法用6种分离培养基,利用涂布平板法分离放线菌;通过PCR扩增获得菌株16S r RNA基因并进行同源性比对,分析放线菌多样性;发酵液经处理分别形成发酵液酯相、发酵液水相和菌丝丙酮浸提液3类样品;纸片扩散法进行抗菌活性测试。结果从5份红树林植物根际淤泥样品中分离纯化得到56株放线菌,分布于7个目7个科12个属,优势菌属为小单孢菌属和红球菌属;菌株L9T122、L1T1Jb1的16S r RNA基因序列与有效发表菌株Agromyces bracchium IFO 16238T(AB023359)、Streptomyces radiopugnans R97T(DQ912930)的相似率最高,分别为97.49%和97.07%,为潜在壤霉菌属和链霉菌属新种;抗菌活性检测结果表明,在20株放线菌中,15株具有抗菌活性,总阳性率为75.00%。其中L2T1Gb21、L9T122对金黄色葡萄球菌和铜绿假单胞菌均有较强的抑菌作用。结论广西北仑河口红树林植物根际土壤中含有较为丰富的放线菌资源,菌株L2T1Gb21、L9T122有较强的抗菌活性,具有开发抗菌新药的潜力。展开更多
Hyperphosphorylation of Tau in Alzheimer＇s disease （AD） brain appears to be caused by a down-regulation of protein phospbatase 2A （PP2A）. In this study, we selectively inhibited PP2A by injection of okadaic acid...Hyperphosphorylation of Tau in Alzheimer＇s disease （AD） brain appears to be caused by a down-regulation of protein phospbatase 2A （PP2A）. In this study, we selectively inhibited PP2A by injection of okadaic acid （OA） into the Meynert nucleus basalis of rats and found that 0.4 pmol of OA injeetion induced approximately 60% inhibition of PP2A 24 h after injection, 13% inhibition 48 h after injection and no obvious inhibition 72 h after injection. Hyperphosphorylation of Tau at Ser-198/ Ser-199/Ser-202 and Ser-396/Ser-404 and spatial memory deficit of rats were induced 24 h after 0. d prnol of OA injection. This study suggests that a dowreregulation of PP2A may underlie almormal hyperphosphorylation of cytoskeletal proteins leading to neurofibrillary degeneration in AD.展开更多
文摘目的从红树林根际淤泥中分离鉴定放线菌并进行多样性分析及抗菌活性研究,为新抗生素的发现提供药用放线菌资源。方法用6种分离培养基,利用涂布平板法分离放线菌;通过PCR扩增获得菌株16S r RNA基因并进行同源性比对,分析放线菌多样性;发酵液经处理分别形成发酵液酯相、发酵液水相和菌丝丙酮浸提液3类样品;纸片扩散法进行抗菌活性测试。结果从5份红树林植物根际淤泥样品中分离纯化得到56株放线菌,分布于7个目7个科12个属,优势菌属为小单孢菌属和红球菌属;菌株L9T122、L1T1Jb1的16S r RNA基因序列与有效发表菌株Agromyces bracchium IFO 16238T(AB023359)、Streptomyces radiopugnans R97T(DQ912930)的相似率最高,分别为97.49%和97.07%,为潜在壤霉菌属和链霉菌属新种;抗菌活性检测结果表明,在20株放线菌中,15株具有抗菌活性,总阳性率为75.00%。其中L2T1Gb21、L9T122对金黄色葡萄球菌和铜绿假单胞菌均有较强的抑菌作用。结论广西北仑河口红树林植物根际土壤中含有较为丰富的放线菌资源,菌株L2T1Gb21、L9T122有较强的抗菌活性,具有开发抗菌新药的潜力。
基金Supported by the National Natural Science Foundation of China(30370560 ,39925012 ,30100057 ,30170221) and a Grant fromthe Li Founda-tion, USA
文摘Hyperphosphorylation of Tau in Alzheimer＇s disease （AD） brain appears to be caused by a down-regulation of protein phospbatase 2A （PP2A）. In this study, we selectively inhibited PP2A by injection of okadaic acid （OA） into the Meynert nucleus basalis of rats and found that 0.4 pmol of OA injeetion induced approximately 60% inhibition of PP2A 24 h after injection, 13% inhibition 48 h after injection and no obvious inhibition 72 h after injection. Hyperphosphorylation of Tau at Ser-198/ Ser-199/Ser-202 and Ser-396/Ser-404 and spatial memory deficit of rats were induced 24 h after 0. d prnol of OA injection. This study suggests that a dowreregulation of PP2A may underlie almormal hyperphosphorylation of cytoskeletal proteins leading to neurofibrillary degeneration in AD.
