[目的]筛选出能高效降解氨氮或总氮的菌株。[方法]以北京市南宫堆肥厂的垃圾渗滤液为材料,并从中筛选出一株具有高效降解氨氮能力的菌株,通过形态观察、革兰氏染色和16S r DNA分子鉴定等方法对其进行种属的鉴定,且对该菌株降解氨氮最适...[目的]筛选出能高效降解氨氮或总氮的菌株。[方法]以北京市南宫堆肥厂的垃圾渗滤液为材料,并从中筛选出一株具有高效降解氨氮能力的菌株,通过形态观察、革兰氏染色和16S r DNA分子鉴定等方法对其进行种属的鉴定,且对该菌株降解氨氮最适条件进行研究。[结果]通过鉴定发现该菌株属于弗式柠檬酸杆菌(Citrobacter freundii),命名为弗式柠檬酸杆菌(Citrobacter freundii) H-1,简称H-1。该菌株在实验室条件下对氨氮的去除最适的p H为7,最适的氨氮浓度为500 mg/L,最适的C/N为8∶1,最适的接种量为1%,最适的C源为红糖∶柠檬酸钠(4∶1)组合的复合C源,在最适的条件下,其对氨氮的降解率为82.5%。[结论]该菌株对处理含有高浓度氨氮的污水具有潜在的应用价值,为环保工作者开发污水中氨氮的高效处理提供理论依据和技术支持。展开更多
The recent progress and future prospects for ultra-centrifugal sedimentation in solids are described,mainly involving equipment,miscible systems and compounds.Almost 90%ultracentrifugation experiments were performed o...The recent progress and future prospects for ultra-centrifugal sedimentation in solids are described,mainly involving equipment,miscible systems and compounds.Almost 90%ultracentrifugation experiments were performed on the 1st and 2nd high-temperature ultracentrifuge which is typically operated at temperatures below 500℃ under the maximum centrifugal acceleration up to 106 g.The strong gravitational and temperature fields induce atomic-scale graded structure,grain growth and refinement,and voids accumulation caused by the atomic sedimentation in miscible systems.New structures,properties and substances are produced in some compounds.A new cantilever high-temperature ultracentrifuge with a test temperature up to 1200℃ is under construction at Zhejiang University,making it possible to simulate the composition,microstructure and property evolution of superalloys in the operating environment of aircraft engines.展开更多
基金National Natural Science Foundation of China(51988101)Fundamental Research Funds for the Central Universities(226-2022-00050)。
文摘The recent progress and future prospects for ultra-centrifugal sedimentation in solids are described,mainly involving equipment,miscible systems and compounds.Almost 90%ultracentrifugation experiments were performed on the 1st and 2nd high-temperature ultracentrifuge which is typically operated at temperatures below 500℃ under the maximum centrifugal acceleration up to 106 g.The strong gravitational and temperature fields induce atomic-scale graded structure,grain growth and refinement,and voids accumulation caused by the atomic sedimentation in miscible systems.New structures,properties and substances are produced in some compounds.A new cantilever high-temperature ultracentrifuge with a test temperature up to 1200℃ is under construction at Zhejiang University,making it possible to simulate the composition,microstructure and property evolution of superalloys in the operating environment of aircraft engines.
