CD-1, a genetically-engineered CHO cell line, was cultivated with a Biosilon microcarrier culture system.We successfully cultivated CD-1 cells to a very high density (over1×107cells/ml). Prourokinase was stably s...CD-1, a genetically-engineered CHO cell line, was cultivated with a Biosilon microcarrier culture system.We successfully cultivated CD-1 cells to a very high density (over1×107cells/ml). Prourokinase was stably secreted at about 180 IU/ 1e6 cells/24 h. Experiments showed that CD-1 cells growing on Biosilon microcarriers were able to spontaneously release from the microcarriers, then reatthch and proliferate on fresh microcarriers. This makes it very easy to scale up preduction. The microcarriers could be reused several times without affecting adhesion. proliferation and prourokinase secretion. With CMPECC membrane radial flow chromatography and MPG chromatography, the prourokinase in conditioned medium could be purified to a specific activity of 1×105 IU/mg of protein. The purification factor was about 600 fold, and approxiamately 90 % of the biological activity was recovered.展开更多
The methane monooxygenase of methanotrophs is capable of catalyzing propene to produce epoxypropane directly in one step,without formation of by-products except water.Compared with the chemical synthesis method for pr...The methane monooxygenase of methanotrophs is capable of catalyzing propene to produce epoxypropane directly in one step,without formation of by-products except water.Compared with the chemical synthesis method for production of epoxypropane,the biosynthesis has promising potential due to the mild reaction conditions,high selectivity and environmental friendliness.In this paper,the conditions were optimized for production of epoxypropane from propene with Methylosinus trichosporim OB3b whole cells cultivated by the traditional method,including temperatures,initial propene concentrations,sodium formate and MgCl2 concentrations,which are important factors affecting the epoxypropane biosythesis.Based on the optimization results,the performance of epoxypropane production carried out with M.trichosporium OB3b of high cell density was investigated,which was obtained by a novel rapid cultivation method developed by the authors.The final concentration of epoxypropane was almost four times of the highest productivity reported so far.展开更多
利用乳清为原料高密度培养干酪乳杆菌(Lactobacillus casei STL3102),用于生产浓缩发酵剂。在5L发酵罐研究了pH控制和补料培养条件,结果表明,加碱控制pH对菌体生长有利,控制pH为6·0时的菌体干重最高。不同碱液对菌体的生长有显著影...利用乳清为原料高密度培养干酪乳杆菌(Lactobacillus casei STL3102),用于生产浓缩发酵剂。在5L发酵罐研究了pH控制和补料培养条件,结果表明,加碱控制pH对菌体生长有利,控制pH为6·0时的菌体干重最高。不同碱液对菌体的生长有显著影响,流加NH3·H2O菌体的产量较高,24h时菌体干重达3·74g/L。在流加NH3·H2O,控制pH6·0条件下,对菌体补料发酵进行了研究。采用30g/L为初始乳清浓度,发酵16h以1·0mL/min恒速补料,发酵44h,菌体干重达4·79g/L,此时测定发酵液中活菌数为1·95×1011CFU/mL。展开更多
文摘CD-1, a genetically-engineered CHO cell line, was cultivated with a Biosilon microcarrier culture system.We successfully cultivated CD-1 cells to a very high density (over1×107cells/ml). Prourokinase was stably secreted at about 180 IU/ 1e6 cells/24 h. Experiments showed that CD-1 cells growing on Biosilon microcarriers were able to spontaneously release from the microcarriers, then reatthch and proliferate on fresh microcarriers. This makes it very easy to scale up preduction. The microcarriers could be reused several times without affecting adhesion. proliferation and prourokinase secretion. With CMPECC membrane radial flow chromatography and MPG chromatography, the prourokinase in conditioned medium could be purified to a specific activity of 1×105 IU/mg of protein. The purification factor was about 600 fold, and approxiamately 90 % of the biological activity was recovered.
文摘The methane monooxygenase of methanotrophs is capable of catalyzing propene to produce epoxypropane directly in one step,without formation of by-products except water.Compared with the chemical synthesis method for production of epoxypropane,the biosynthesis has promising potential due to the mild reaction conditions,high selectivity and environmental friendliness.In this paper,the conditions were optimized for production of epoxypropane from propene with Methylosinus trichosporim OB3b whole cells cultivated by the traditional method,including temperatures,initial propene concentrations,sodium formate and MgCl2 concentrations,which are important factors affecting the epoxypropane biosythesis.Based on the optimization results,the performance of epoxypropane production carried out with M.trichosporium OB3b of high cell density was investigated,which was obtained by a novel rapid cultivation method developed by the authors.The final concentration of epoxypropane was almost four times of the highest productivity reported so far.
文摘利用乳清为原料高密度培养干酪乳杆菌(Lactobacillus casei STL3102),用于生产浓缩发酵剂。在5L发酵罐研究了pH控制和补料培养条件,结果表明,加碱控制pH对菌体生长有利,控制pH为6·0时的菌体干重最高。不同碱液对菌体的生长有显著影响,流加NH3·H2O菌体的产量较高,24h时菌体干重达3·74g/L。在流加NH3·H2O,控制pH6·0条件下,对菌体补料发酵进行了研究。采用30g/L为初始乳清浓度,发酵16h以1·0mL/min恒速补料,发酵44h,菌体干重达4·79g/L,此时测定发酵液中活菌数为1·95×1011CFU/mL。
