Dynamic Promotion and Suppression Model for Plasmid Conjugal Transfer Under a Flow Condition

Abstract

Recipients (the plasmid-free bacteria) receive a copy of plasmid from donors (the plasmid-bearing bacteria) and become transconjugants. In case of the plasmid has a gene providing a drug resistant, recalcitrant substance and so on, these functions are transferred with plasmid carrying. Plasmid transfer makes a substantial contribution an ability to adjust to the environment. Plasmid transfer is mainly performed by conjugation, called conjugal transfer, of a pair of bacteria. Conjugal transfer need to approach the bacteria bodies. Meanwhile, in nature, bacteria lives in not only solid conditions such as soil but also liquid conditions such as rivers. Therefore dynamic analysis of plasmid in the liquid condition is very important. Conjugal transfer is affected by a stream of the liquid condition, because the behavior of bacteria is controlled by the stream. However, relationship between flow condition and the number of transconjugants isn’t currently clarified. Therefore, in this study, we aim at analysis of plasmid dynamics under the flow condition. We develop a model with promotion and suppression term for relations between flow condition and the number of transconjugants, and identifying parameters by using the experimental data at agitating flask.