Knudsen G R, Walter M V, Porteous L A, Prince V J, Armstrong J L, Seidler R J
Corvallis Environmental Research Laboratory, U.S. Environmental Protection Agency, Oregon 97333.
Appl Environ Microbiol. 1988 Feb;54(2):343-7. doi: 10.1128/aem.54.2.343-347.1988.
A computer simulation model was used to predict the dynamics of survival and conjugation of Pseudomonas cepacia (carrying the transmissible recombinant plasmid R388:Tn1721) with a nonrecombinant recipient strain in simple rhizosphere and phyllosphere microcosms. Plasmid transfer rates were derived for a mass action model, and donor and recipient survival were modeled as exponential growth and decay processes or both. Rate parameters were derived from laboratory studies in which donor and recipient strains were incubated in test tubes with a peat-vermiculite solution or on excised radish or bean leaves in petri dishes. The model predicted donor, recipient, and transconjugant populations in hourly time steps. It was tested in a microcosm planted with radish seeds and inoculated with donor and recipient strains and on leaf surfaces of radish and bean plants also growing in microcosms. Bacteria were periodically enumerated on selective media over 7 to 14 days. When donor and recipient populations were 10(6) to 10(8) CFU/g (wet weight) of plant or soil, transconjugant populations of about 10(1) to 10(4) were observed after 1 day. An initial rapid increase and a subsequent decline in numbers of transconjugants in the rhizosphere and on leaf surfaces were correctly predicted.
利用计算机模拟模型预测洋葱伯克霍尔德菌（携带可转移重组质粒R388:Tn1721）与非重组受体菌株在简单根际和叶际微宇宙中的存活和接合动态。从质量作用模型得出质粒转移率，并将供体和受体的存活建模为指数生长和衰减过程或两者兼有。速率参数来自实验室研究，其中供体和受体菌株在装有泥炭-蛭石溶液的试管中或在培养皿中的离体萝卜或豆叶上孵育。该模型按小时时间步长预测供体、受体和接合子群体。在种植萝卜种子并接种供体和受体菌株的微宇宙以及同样生长在微宇宙中的萝卜和豆类植物的叶表面进行了测试。在7至14天内定期在选择性培养基上对细菌进行计数。当供体和受体群体为每克（湿重）植物或土壤10(6)至10(8)CFU时，1天后观察到接合子群体约为10(1)至10(4)。正确预测了根际和叶表面接合子数量最初的快速增加和随后的下降。
