试验初步探讨了毛霉培养条件对其胞内代谢产物稳定性的影响。以单一菌株为研究对象,探讨了培养基、接种量、培养时间、培养温度、摇瓶速度等因素对菌株胞内代谢产物HPLC图谱的影响,分析各因素的影响大小,建立了规范化的培养流程:选用马...试验初步探讨了毛霉培养条件对其胞内代谢产物稳定性的影响。以单一菌株为研究对象,探讨了培养基、接种量、培养时间、培养温度、摇瓶速度等因素对菌株胞内代谢产物HPLC图谱的影响,分析各因素的影响大小,建立了规范化的培养流程:选用马铃薯制作马铃薯葡萄糖培养基,按每支18×180 mm试管装载30 m L进行分装,灭菌后接种2 m L的孢子悬液,在温度设为20℃的恒温摇床中以150 r/min摇瓶速度摇瓶培养4 d后取出。展开更多
酿酒酵母是发酵产业中的关键微生物,处于对数生长期的酵母菌迅速繁殖,积累大量初级代谢产物,对此时期进行调控可以提高发酵效率。为了解对数生长期酿酒酵母发酵情况,采用液相色谱串联质谱法(liquid chromatography tandem mass spectrom...酿酒酵母是发酵产业中的关键微生物,处于对数生长期的酵母菌迅速繁殖,积累大量初级代谢产物,对此时期进行调控可以提高发酵效率。为了解对数生长期酿酒酵母发酵情况,采用液相色谱串联质谱法(liquid chromatography tandem mass spectrometry,LC-MS/MS)对酵母胞内主要代谢物及其代谢途径进行分析。结果表明,在对数生长期酿酒酵母胞内共鉴定927种代谢物,含氮和含硫化合物数量及相对含量均最高。这些代谢物参与的代谢途径中,核苷酸代谢、辅因子和维生素代谢、碳水化合物代谢以及氨基酸代谢为酿酒酵母主要代谢途径,核苷酸代谢中相对含量最高的为嘧啶代谢。代谢物和代谢途径主要涉及酵母细胞膜的构建,遗传信息的复制,信号分子的传递,渗透压的调节等。为酵母提供生长所需的基本小分子物质和能量,同时为合成蛋白质、核酸等生物大分子物质提供原料。此外,碳水化合物和氨基酸代谢的代谢流分布可更好地支持酿酒酵母进行核苷酸代谢,促进酵母菌的增殖、生长和存活。该研究结果为定向改造酿酒酵母、提高其发酵效率提供一定科学依据。展开更多
Endostatin is a natural occurred angiogenesis inhibitor derived from collagenXVIII. So far its function during the angiogenesis process of bone formation and arthropathy has not been well studied yet. The present stud...Endostatin is a natural occurred angiogenesis inhibitor derived from collagenXVIII. So far its function during the angiogenesis process of bone formation and arthropathy has not been well studied yet. The present study addresses the function of endostatin in rabbit articular chondrocytes (RAC). We found that endostatin can promote RAC adhesion and spreading as well as its proliferation. In monolayer cultured RAC, CollagenII, TIMP1 and collagenXVIII transcription were up regulated by endostatin while collagenI and MMP9 were down regulated. Moreover collagenXVIII and endostatin antigens are present at synovial fluid. These findings indicate new function of endostatin as a homeostatic factor in cartilage metabolism.展开更多
Au nanoclusters （AuNCs） hold tremendous potential to be employed in a wide variety of biological applications. Despite the rapid development in the field of NCs synthesis, a comprehensive understanding of how cells ...Au nanoclusters （AuNCs） hold tremendous potential to be employed in a wide variety of biological applications. Despite the rapid development in the field of NCs synthesis, a comprehensive understanding of how cells interact with this class of ultra-small nanoparticles （〈2 nm） having defined sizes and surface chemistry, remains poorly understood. In this study, we show that the choice of the surface ligand used to protect AuNCs can significantly perturb cellular uptake and intracellular redox signaling. A panel of monodisperse, atomically precise AuNCs with different core Au atom number （i.e., Auls, Au18 and Au25） protected with either mercaptopropionic acid （MPA） or glutathione （GSH） capping agent were synthesized and their effects on the generation of intracellular reactive oxygen species （ROS）, cytotoxicity and genotoxicity of the NCs were assessed. Both mitochondrial superoxide anion （O2^-） and cytoplasmic ROS were found to be higher in cells exposed to MPA but not GSH capped AuNCs. The unregulated state of intracellular ROS is correlated to the amount of internalized AuNCs. Interestingly, MPA-AuNCs induction of ROS level did not lead to any detrimental cellular effects such as cell death or DNA damage. Instead, it was observed that the increase in redox status corresponded to higher cellular metabolism and proliferative capacity. Our study illustrates that surface chemistry of AuNCs plays a pivotal role in affecting the biological outcomes and the new insights gained will be useful to form the basis of defining specific design rules to enable rational engineering of ultra-small complex nanostructures for biological applications.展开更多
文摘试验初步探讨了毛霉培养条件对其胞内代谢产物稳定性的影响。以单一菌株为研究对象,探讨了培养基、接种量、培养时间、培养温度、摇瓶速度等因素对菌株胞内代谢产物HPLC图谱的影响,分析各因素的影响大小,建立了规范化的培养流程:选用马铃薯制作马铃薯葡萄糖培养基,按每支18×180 mm试管装载30 m L进行分装,灭菌后接种2 m L的孢子悬液,在温度设为20℃的恒温摇床中以150 r/min摇瓶速度摇瓶培养4 d后取出。
文摘酿酒酵母是发酵产业中的关键微生物,处于对数生长期的酵母菌迅速繁殖,积累大量初级代谢产物,对此时期进行调控可以提高发酵效率。为了解对数生长期酿酒酵母发酵情况,采用液相色谱串联质谱法(liquid chromatography tandem mass spectrometry,LC-MS/MS)对酵母胞内主要代谢物及其代谢途径进行分析。结果表明,在对数生长期酿酒酵母胞内共鉴定927种代谢物,含氮和含硫化合物数量及相对含量均最高。这些代谢物参与的代谢途径中,核苷酸代谢、辅因子和维生素代谢、碳水化合物代谢以及氨基酸代谢为酿酒酵母主要代谢途径,核苷酸代谢中相对含量最高的为嘧啶代谢。代谢物和代谢途径主要涉及酵母细胞膜的构建,遗传信息的复制,信号分子的传递,渗透压的调节等。为酵母提供生长所需的基本小分子物质和能量,同时为合成蛋白质、核酸等生物大分子物质提供原料。此外,碳水化合物和氨基酸代谢的代谢流分布可更好地支持酿酒酵母进行核苷酸代谢,促进酵母菌的增殖、生长和存活。该研究结果为定向改造酿酒酵母、提高其发酵效率提供一定科学依据。
文摘Endostatin is a natural occurred angiogenesis inhibitor derived from collagenXVIII. So far its function during the angiogenesis process of bone formation and arthropathy has not been well studied yet. The present study addresses the function of endostatin in rabbit articular chondrocytes (RAC). We found that endostatin can promote RAC adhesion and spreading as well as its proliferation. In monolayer cultured RAC, CollagenII, TIMP1 and collagenXVIII transcription were up regulated by endostatin while collagenI and MMP9 were down regulated. Moreover collagenXVIII and endostatin antigens are present at synovial fluid. These findings indicate new function of endostatin as a homeostatic factor in cartilage metabolism.
文摘Au nanoclusters （AuNCs） hold tremendous potential to be employed in a wide variety of biological applications. Despite the rapid development in the field of NCs synthesis, a comprehensive understanding of how cells interact with this class of ultra-small nanoparticles （〈2 nm） having defined sizes and surface chemistry, remains poorly understood. In this study, we show that the choice of the surface ligand used to protect AuNCs can significantly perturb cellular uptake and intracellular redox signaling. A panel of monodisperse, atomically precise AuNCs with different core Au atom number （i.e., Auls, Au18 and Au25） protected with either mercaptopropionic acid （MPA） or glutathione （GSH） capping agent were synthesized and their effects on the generation of intracellular reactive oxygen species （ROS）, cytotoxicity and genotoxicity of the NCs were assessed. Both mitochondrial superoxide anion （O2^-） and cytoplasmic ROS were found to be higher in cells exposed to MPA but not GSH capped AuNCs. The unregulated state of intracellular ROS is correlated to the amount of internalized AuNCs. Interestingly, MPA-AuNCs induction of ROS level did not lead to any detrimental cellular effects such as cell death or DNA damage. Instead, it was observed that the increase in redox status corresponded to higher cellular metabolism and proliferative capacity. Our study illustrates that surface chemistry of AuNCs plays a pivotal role in affecting the biological outcomes and the new insights gained will be useful to form the basis of defining specific design rules to enable rational engineering of ultra-small complex nanostructures for biological applications.
