Beaudoin D L, Bryers J D, Cunningham A B, Peretti S W
Department of Chemical, Bio and Materials Engineering, Arizona State University, Tempe, Arizona 85287, USA.
Biotechnol Bioeng. 1998 Feb 5;57(3):272-9.
A strain of Pseudomonas putida harboring plasmids RK2 and pDLB101 was exposed to a pure culture biofilm of Bacillus azotoformans grown in a rotating annular reactor under three different concentrations of the limiting nutrient, succinate. Experimental results demonstrated that the broad host range RSF1010 derivative pDLB101 was transferred to and expressed by B. azotoformans. At the lower concentrations, donor mediated plasmid transfer increased with increasing nutrient levels, but the highest nutrient concentration yielded the lowest rate of donor to recipient plasmid transfer. For transconjugant initiated transfer, the rate of transfer increased with increasing nutrient concentrations for all cases. At the lower nutrient concentrations, the frequency of plasmid transfer was higher between donors and recipients than between transconjugants and recipients. The reverse was true at the highest succinate concentration. The rates and frequencies of plasmid transfer by mobilization were compared to gene exchange by retrotransfer. The initial rate of retrotransfer was slower than mobilization, but then increased dramatically. Retrotransfer produced a plasmid transfer frequency more than an order of magnitude higher than simple mobilization.
将携带质粒RK2和pDLB101的恶臭假单胞菌菌株，置于旋转环形反应器中，在三种不同浓度的限制性营养物质琥珀酸盐条件下，使其接触固氮芽孢杆菌的纯培养生物膜。实验结果表明，广宿主范围的RSF1010衍生物pDLB101被转移至固氮芽孢杆菌并在其中表达。在较低浓度下，供体介导的质粒转移随营养水平的增加而增加，但最高营养浓度下供体到受体的质粒转移率最低。对于接合子起始转移，在所有情况下转移率均随营养浓度的增加而增加。在较低营养浓度下，供体与受体之间的质粒转移频率高于接合子与受体之间的频率。在最高琥珀酸盐浓度下情况则相反。将通过迁移进行质粒转移的速率和频率与通过反向转移进行基因交换的情况进行了比较。反向转移的初始速率比迁移慢，但随后急剧增加。反向转移产生的质粒转移频率比简单迁移高出一个数量级以上。
