Influence mechanism of low-dose ionizing radiation on Escherichia coli DH5α population based on plasma theory and system dynamics simulation

J Environ Radioact. 2016 Jan:151 Pt 1:185-192. doi: 10.1016/j.jenvrad.2015.10.007. Epub 2015 Oct 22.

Abstract

It remains a mystery why the growth rate of bacteria is higher in low-dose ionizing radiation (LDIR) environment than that in normal environment. In this study, a hypothesis composed of environmental selection and competitive exclusion was firstly proposed from observed phenomena, experimental data and microbial ecology. Then a LDIR environment simulator (LDIRES) was built to cultivate a model organism of bacteria, Escherichia coli (E. coli) DH5α, the accurate response of bacterial population to ionizing radiation intensity variation was measured experimentally, and then the precise relative dosage of ionizing radiation E. coli DH5α population received was calculated by finite element analysis based on drift-diffusion equations of plasma. Finally, a highly valid mathematical model expressing the relationship between E. coli DH5α population and LDIR intensity was developed by system dynamics based on hypotheses, experimental data and microbial ecology. Both experiment and simulation results clearly showed that the E. coli DH5α individuals with greater specific growth rate and lower substrate consumption coefficient would adapt and survive in LDIR environment and those without such adaptability were finally eliminated under the combined effects of ionizing radiation selection and competitive exclusion.

Keywords: Escherichia coli DH5α; Finite element calculation; Low-dose ionizing radiation; Plasma; System dynamics simulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Evolution
  • Dose-Response Relationship, Radiation
  • Escherichia coli / growth & development
  • Escherichia coli / metabolism
  • Escherichia coli / radiation effects*
  • Finite Element Analysis
  • Models, Theoretical
  • Plasma Gases / chemistry
  • Radiation, Ionizing*
  • Space Simulation

Substances

  • Plasma Gases