Jones I M, Primrose S B, Robinson A, Ellwood D C
J Bacteriol. 1981 Jun;146(3):841-6. doi: 10.1128/jb.146.3.841-846.1981.
The observed transformation frequency by plasmid deoxyribonucleic acid of Escherichia coli grown in continuous culture was found to depend on both the steady-state growth rate and the type of nutrient used to limit growth. With carbon, nitrogen, or phosphorus limitation, the faster the growth rate, the higher the transformation frequency. The increase in transformation frequency associated with higher rates was shown to be due to more transformable cells in the population rather than an increased efficiency of deoxyribonucleic acid uptake. Growth rate had relatively little effect on the transformability of cells from sulfate- and Mg2+-limited chemostats, indicating that some factor other than the growth rate must influence the frequency of transformation. Regardless of the nutrient limitation or the growth rate, no transformants were obtained in the absence of CaCl2.
在连续培养条件下生长的大肠杆菌中，通过质粒脱氧核糖核酸观察到的转化频率被发现既取决于稳态生长速率，也取决于用于限制生长的营养物质类型。在碳、氮或磷限制的情况下，生长速率越快，转化频率越高。与较高生长速率相关的转化频率增加被证明是由于群体中可转化细胞增多，而不是脱氧核糖核酸摄取效率提高。生长速率对来自硫酸盐和镁离子限制的恒化器中的细胞的可转化性影响相对较小，这表明除生长速率外的某些因素必定影响转化频率。无论营养限制或生长速率如何，在没有氯化钙的情况下均未获得转化体。
