Research On The Biological Effects Of Escherichia Coli Induced By Ion Beam And High-Voltage Elecstostatic Field Using LacI Screening System

Low-energy ion implantation has been considered as a new kind of mutation breeding techniques. People are very excited by the fruit which they have obtained for past the decades, but they do not master the biological effects and the function mechanisms of the technique and the law of inheritance in the microorganism irradiated by low-energy ions so far. At the same time, there are some other problems. For example, the heredity character of the mutant was unstable etc. But the combination function with different inducers generally present some superiorities and can increase mutant frequency. This is the developmental trend at present. What is more, HVEF has become more and more important due to its properties of economize energy, practicality and environmental conservation.In the experiments, choosing the Escherichia coli as the target of low-energy ion implantation cooperated with HVEF irradiation, taking the lacI gene which has been studied widely as aim, and screening its mutants, a series of experiment were done, look forward to get a better result.Firstly, we studied the interaction between low-energy N⁺ and E.coli by implanting different N⁺ doses, then analyzing the survival rate and mutant frequency. Ultimately, we ascertained the optimum implanting parameter.Secondly, we discussed the survival rate of E.coli irradiated by HVEF with different intensity and time. The results showed that the dose of E1(2.2 kv/cm×6min) and E2(5.4 kv/cm×18min) had different action to it. E1 could give rise to an obvious activation on germination, compared with the control, the survival rate increased 35.6%. While an effect of E2 was antiblastic.Thirdly, we chiefly discussed the biological effects of E.coli which was induced by N⁺ beam and HVEF. the mutant frequency of E.coli irradiated by different combination doses increased differently, and choosing El to cooperate with N⁺ beam excel choosing E2.Meanwhile, the optimum combination is Eland 90×2.6×10¹³ ions/cm² .Fourthly, the mutant caused only by N⁺ implanting was unstable. If the mutant was irradiated by HVEF during its passage, it seemingly showed that HVEF had many positive effects on the mutant which induced by N⁺ beam. So the combination function of HVEF and N⁺ beam will has a wider foreground.Finally, so much data that related to lacI has been accumulated by researchers. These data will apply researchers more help to study the mutational mechanism. The results of this paper could offer a basic data to study the mutational mechanism of the combination function of HVEF and N⁺ beam at molecule level.