The Study On The Antibacterial Property Of Rare-Nanomaterial

Objective To study the antibacterial property of rare-earth nanomaterial and to investigate its mechanism from the moleculer level.Method The minimum concentration of rare-earth nanomaterial on E. coli and S. au-reus were detected respectively. The experimental groups (induing different concentration of nanomaterial) and the control groups (induing no nanomaterial) were established. We abstracted the DNA and RNA of the bacteria and detected the value of A260. we carried out an dot hybridization experiment on the mRNA of the bacteria in order to learn if rare-earth nanomaterial effected some genes expression. By checking the Genome on the internet we selected some protein-coding genes which have much relation with the growth and metabolism of the bacteria. Those genes were amplified with polymerase chain reaction. Their amplified products were cleaved by some restriction enzymes and were further given a sequence analysis. By the above comprehensive analysis we evaluated the effect of rare-earth nanomaterial on the moleculer level.Results (1) The minimum concentration of rare-earth nanomaterial on E. coli and S. aureus were respectively 2mg/mland 0. 125mg/ml. (2) It was showed that there were much difference between the value of the A of experimental groups and control groups from the analysis result (E. coli F=44. 58,P<0. 01; S. aureus F=45. 10,P<0. 01). CD It was also showed that the expression of the gene holB of the experiment groups were lower than that of the control groups (OPTMD P<0. 01) (4)The enzyme spectrum of experimental team was similar with that of control team. (5)The consistency of both team's DNA sequence was between 97. 4%and 98. 5%. The mutation of base largely occurred on G-A,T-C . (6)The second structure of amino acid of the aim genes were varied with different degree a-mong which that of Holb was varied mostly and its helix almost vanished.Conclusion (1) The rare-earth nanomaterial have had strong antibacterial capability. (2) The rare-earth nanomaterial inhibit the sythesis of DNA and the expression of genes . (3) It was presumed that the change of Holb's second structure might have effection on its founction so that the bacteria couldn't mutiply normaly and were killed.