Escherichia Coli Induced By High-pressure And Analysis The Mutation With RAPD

In this paper, selected as the starting wild strains of E. coli, were used 100Mpa, 200 Mpa, 300 Mpa pressure gradient to deal with the wild E. coli, by observing that with the increased pressure, decreased cell survival. so death rates is inversely proportional to pressure. Survival strains with different temperature, medium to filter out the mutant. after Auxotrophic screening,there is not Auxotrophic, but this does not mean that the high-pressure can not produce Auxotrophic. With temperature screening, found a temperature-sensitive strain, the strain in the 65℃and higher temperatures can not survive, but after several generations culturing,the phenomenon still exists.Mutant strain with the control of the growth curve have significant differences. mutant to reach a stable phase of the time period longer than the wild strain, and the logarithmic phase less than the control. Control strain has entered into a recession phase earlier than the mutant. The bacterial total protein were extracted respectively from control and mutant strains for SDS-PAGE electrophoresis and found a significant differet bands. This shows that under conditions of high pressure will produce a series of protein-induced cell to resist external ultra-high pressure to maintain the normal activities of life. Changes in the proteome is closely linked to the genome, if we say that a direct impact on protein changes in phenotype, then the gene directly determine the protein expression. Through genomics method of genetic markers, RAPD to detect changes in gene polymorphism, which changes in gene discovery. Extracting genomic DNA from the wild and mutant strain, through the RAPD molecular marker technology to scan control and mutant strain genomic DNA, to observe the molecular level changes of the mutant caused by high pressure in the genetic trait. The DNA sequences were submitted to GeneBank.Homology search was performed within GenBank's database using the BLAST (Basic Local Alignment Search Tool) algorithm. After blasting, we know that six sequences are galactose, glucosamine phosphate mutase, ABC transporter, xanthine dehydrogenase from a conservative family of proteins (hypothetical protein). Galactose and ABC transporters are related to energy metabolism. glucosamine phosphate mutase is related to the cell wall and membrane protein synthesis. xanthine dehydrogenase is related to the hydroxyproline metabolism and conserved protein is a protein related to a conservative family protein is likely to be the correct number of proteins related to protein folding. This shows that the effects of cells after treated with high pressure and life-sustaining activities are most relevant to a number of metabolic activities, and some proteins, enzymes play a key role.