Microbial community and functional genes in the rhizosphere of alfalfa in crude oil-contaminated soil  

作　　者：YiZHONG Jian WANG Yizhi SONG Yuting LIANG Guanghe LI 

机构地区：[1]School of Environment,Tsinghua University,Beijing 100084,China [2]State Key Joint Laboratory of Environmental Simulation and Pollution Control,Tsinghua University,Beijing 100084,China

出　　处：《Frontiers of Environmental Science & Engineering》2012年第6期797-805,共9页环境科学与工程前沿（英文）

摘　　要：A rhizobox system constructed with crude oil- contaminated soil was vegetated with alfalfa （Medicago sativa L.） to evaluate the rhizosphere effects on the soil microbial population and functional structure, and to explore the potential mechanisms by which plants enhance the removal of crude oil in soil. During the 80-day experiment, 31.6% of oil was removed from the adjacent rhizosphere （AR）; this value was 27% and 53% higher than the percentage of oil removed from the far rhizosphere （FR） and from the non-rhizosphere （NR）, respectively. The populations of heterotrophic bacteria and hydrocarbon- degrading bacteria were higher in the AR and FR than in the NR. However, the removal rate of crude oil was positively correlated with the proportion of hydrocarbon- degrading bacteria in the rhizosphere. In total, 796, 731, and 379 functional genes were detected by microarray in the AR, FR, and NR, respectively. Higher proportions of functional genes related to carbon degradation and organic remediation, were found in rhizosphere soil compared with NR soil, suggesting that the rhizosphere selectively increased the abundance of these specific functional genes. The increase in water-holding capacity and decrease in pH as well as salinity of the soil all followed the order of AR 〉 FR 〉 NR. Canonical component analysis showed that salinity was the most important environmental factor influencing the microbial functional structure in the rhizosphere and that salinity was negatively correlated with the abundance of carbon and organic degradation genes.A rhizobox system constructed with crude oil- contaminated soil was vegetated with alfalfa （Medicago sativa L.） to evaluate the rhizosphere effects on the soil microbial population and functional structure, and to explore the potential mechanisms by which plants enhance the removal of crude oil in soil. During the 80-day experiment, 31.6% of oil was removed from the adjacent rhizosphere （AR）; this value was 27% and 53% higher than the percentage of oil removed from the far rhizosphere （FR） and from the non-rhizosphere （NR）, respectively. The populations of heterotrophic bacteria and hydrocarbon- degrading bacteria were higher in the AR and FR than in the NR. However, the removal rate of crude oil was positively correlated with the proportion of hydrocarbon- degrading bacteria in the rhizosphere. In total, 796, 731, and 379 functional genes were detected by microarray in the AR, FR, and NR, respectively. Higher proportions of functional genes related to carbon degradation and organic remediation, were found in rhizosphere soil compared with NR soil, suggesting that the rhizosphere selectively increased the abundance of these specific functional genes. The increase in water-holding capacity and decrease in pH as well as salinity of the soil all followed the order of AR 〉 FR 〉 NR. Canonical component analysis showed that salinity was the most important environmental factor influencing the microbial functional structure in the rhizosphere and that salinity was negatively correlated with the abundance of carbon and organic degradation genes.

关 键 词：crude oil-contaminated soil phytoremedia-tion rhizosphere effects RHIZOBOX functional genes 

分 类 号：X53[环境科学与工程—环境工程] S571.1[农业科学—茶叶生产加工]