通氣量、培養基碳源與氮源比例對基因重組酵素分泌性影響之研究

• Main Author: 吳業雄
• Other Authors: 鄭智元
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/50088285539198632360

碩士 === 國立成功大學 === 化學工程研究所 === 85 === The relationships between the percentage of creatinase excretion and the fatty acid composition of cell membrane lipid of Escherichia. coli JM109 (pSCRO5) at various cultivation conditions (C/N ratio and dissolved oxygen level) was investigated in this study. Cells cultivated at C/N ratio=O.1 resulted in a high percentage of enzyme excretion, as compared with the other C/N ratios. The highest percentage of creatinase excretion from E. coli cells was obtained when the dissolved oxygen was controlled at 5~10% or 30~35%. The result also showed that the percentage of creatinase excretion increased as increasing in the percentage of unsaturated fatty acid (UFA) of the cell membrane lipid. As indicated by the other report, the increase in the fluidity of cell membrane was resulted from increasing in the percentage of UFA of lipid. Therefore, it was thought that excretion of creatinase was due to increasing in the fluidity of cell membrane. During the continuous operation, specific creatinase activity, the percentage of creatinase excretion and UFA of cell membrane lipid increased as decreasing in dilution rate. It is indicated that the fluidity of E. coli cell membrane decreased with the increase of dilution rate, which resulted in the decrease of the percentage of creatinase excretion.