Screening And Diversity Analysis Of Oil-degrading Bacteria

At present,petroleum hydrocarbon pollution has become a problem of soil environmental pollution that cannot be ignored in many regions.There are many sources of petroleum hydrocarbon pollutants,including oil spills,discharge of oily waste from factories,and settlement of air and accumulation of oily waste during mining and smelting.These petroleum hydrocarbon pollutants will damage the soil structure and affect the local ecological environment and crop growth and development.In turn,it poses a security threat and economic loss to human beings.Biodegradation is considered to be one of the effective methods for degrading petroleum hydrocarbon pollution.It has become a research hotspot because of its small pollution to the surrounding environment,easy operation and low cost.Soil samples were collected from Dongying and Zibo,these samples were screened,sequenced and characterized the oil-degrading bacteria.On the other hand,in order to explore the effects of petroleum hydrocarbon pollutants on microbial diversity under natural conditions,high-throughput sequencing and correlation analysis were also performed on the samples.The main findings of the study were as follows:1.Samples were collected from Zibo and Dongying in the experiment,and the petroleum was used as the sole carbon source to screen and identify petroleum-degrading bacteria.35 strains of bacteria were identified by sequencing,including 6 strains of Pseudomonas,5 strains of Bacillus,4 strains of Acinetobacter,3 strains of Stenotrophomonas,3 strains of Rhodococcus,3 strains of Achromobacter,1 strain of Enterobacter,1 strain of Brevundimonas,1 strain of Paracoccus,1 strain of Albirhodobacter 1 strain of Halomonas,1 strain of Rheinheimera.1 strain of Salinacola,1 strain of Microbacterium,and 1 strain of Brevibacterium.2.Subsequent data on growth and degradation rates were measured.From the results obtained,at 18?,most strains showed a longer lag phase and a smaller maximum growth,and the growth conditions at 28? and 38 ? were approximately the same,and the maximum growth at 38 0C was greater than the maximum growth at 28 ?.However,some strains had a larger maximum growth at 18 0C and a longer stationary period.In terms of degradation rate,the degradation rate of the strain was above 30%,and the degradation rate of most strains increased.with the increase of temperature.The strains ZB-100-1 and ZB-100-2 showed an increase in degradation rate at 18 ?.3.High-throughput sequencing was used to analysis Zibo and Dongying soils.The results showed that petroleum hydrocarbon pollutants would change the microbial community structure in the soil,such as reducing the microbial species richness and changing the composition of dominant flora in the soil.The microbial species richness of soil samples without petroleum hydrocarbons in Zibo and Dongying was higher than that of petroleum hydrocarbon contaminated soil samples.There was no significant difference in species richness and uniformity between Zibo soil samples.However,the microbial community structure showed significant differences,especially the changes in dominant flora.Compared with the blank control,the contaminated soil samples in Dongying significantly reduced the microbial species richness.The dominant species between each of the soils of Dongying and Zibo showed some differences.Compared with soil samples not contaminated with petroleum hydrocarbons,the relative abundance of the dominant strains in contaminated soil samples Salinimicrobium,Marinobacter,Gramella,Altererythrobacter,Segetibacter,Marinobacter,Gillisia,and Halomonas was significantly reduced.It can be seen that serious oil and hydrocarbon pollution will have a certain impact on the local soil environment.