The problem of equilibrium of non-linear dynamic system for microorganism in continuous culture is considered in this paper. The existence of equilibrium point is proved. The conclusion that the equilibrium is the con...The problem of equilibrium of non-linear dynamic system for microorganism in continuous culture is considered in this paper. The existence of equilibrium point is proved. The conclusion that the equilibrium is the continuous function of the dilution rate and substrate concentration in medium in a certain range is concluded. And the stability criterion of equilibrium is obtained. In theory, it explains the multiplicity shown in laboratory.展开更多
According to the recent investigation on cell cycle of fission yeast, a mathematical dynamic model is for-mulated. Four cyclins, e.g. Puc1, Cig1, Cig2 and Cdc13, are investigated here. The interacting networks between...According to the recent investigation on cell cycle of fission yeast, a mathematical dynamic model is for-mulated. Four cyclins, e.g. Puc1, Cig1, Cig2 and Cdc13, are investigated here. The interacting networks between the cy-clins and the process of cell cycle are mathematically de-scribed. The functions of these cyclins are particularly ana-lyzed. Comparison among different mutants indicates that the cyclins play an important role in cell cycle.展开更多
The separation of 1,3-propanediol from the glycerol-based fermentation broth of Klebsiella pneumoniae plays an important role during the microbial production of 1,3-propanediol.In this paper,the separation of 1,3-prop...The separation of 1,3-propanediol from the glycerol-based fermentation broth of Klebsiella pneumoniae plays an important role during the microbial production of 1,3-propanediol.In this paper,the separation of 1,3-propanediol from fermentative broth by a combination of ultrafiltration and alcohol dilution crystallization was investi-gated.The broth was first filtered by ultrafiltration,and 99%of cells,89.4%of proteins and 69%of nucleic acids were removed.The obtained broth was further condensed by vacuum distillation,and then alcohol was added.The macro-molecular impurities,such as nucleic acids,polysaccharides and proteins,were precipitated,and inorganic and organic salts were crystallized.The optimal volume ratio of alcohol added to the condensed fermentation broth was determined to be 2:1.As a result,proteins,nucleic acids and electric conduc-tivity decreased by 97.4%,89.7%and 95.8%,respectively,compared with the fermentative broth.The influences of pH and water content in condensed broth on alcohol precipi-tation and dilution crystallization were also investigated.The experimental results indicated that alcohol precipitation and dilution crystallization was feasible and effective for the separation of 1,3-propanediol from actual fermentation broth.展开更多
文摘The problem of equilibrium of non-linear dynamic system for microorganism in continuous culture is considered in this paper. The existence of equilibrium point is proved. The conclusion that the equilibrium is the continuous function of the dilution rate and substrate concentration in medium in a certain range is concluded. And the stability criterion of equilibrium is obtained. In theory, it explains the multiplicity shown in laboratory.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China(Grant No.20176005).
文摘According to the recent investigation on cell cycle of fission yeast, a mathematical dynamic model is for-mulated. Four cyclins, e.g. Puc1, Cig1, Cig2 and Cdc13, are investigated here. The interacting networks between the cy-clins and the process of cell cycle are mathematically de-scribed. The functions of these cyclins are particularly ana-lyzed. Comparison among different mutants indicates that the cyclins play an important role in cell cycle.
基金supported by the National Basic Research Program of China(“973”project,Grant No.2003CB716000)the Tenth Five-Years’Projects of China Science and Technology Ministry(Grant No.2004BA713B06-03)the National Natural Science Foundation of China(Grant No.20576018).
文摘The separation of 1,3-propanediol from the glycerol-based fermentation broth of Klebsiella pneumoniae plays an important role during the microbial production of 1,3-propanediol.In this paper,the separation of 1,3-propanediol from fermentative broth by a combination of ultrafiltration and alcohol dilution crystallization was investi-gated.The broth was first filtered by ultrafiltration,and 99%of cells,89.4%of proteins and 69%of nucleic acids were removed.The obtained broth was further condensed by vacuum distillation,and then alcohol was added.The macro-molecular impurities,such as nucleic acids,polysaccharides and proteins,were precipitated,and inorganic and organic salts were crystallized.The optimal volume ratio of alcohol added to the condensed fermentation broth was determined to be 2:1.As a result,proteins,nucleic acids and electric conduc-tivity decreased by 97.4%,89.7%and 95.8%,respectively,compared with the fermentative broth.The influences of pH and water content in condensed broth on alcohol precipi-tation and dilution crystallization were also investigated.The experimental results indicated that alcohol precipitation and dilution crystallization was feasible and effective for the separation of 1,3-propanediol from actual fermentation broth.
