Siciliano Steven D, Germida James J, Banks Kathy, Greer Charles W
Environmental Microbiology Group, Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec.
Appl Environ Microbiol. 2003 Jan;69(1):483-9. doi: 10.1128/AEM.69.1.483-489.2003.
The purpose of this study was to investigate the mechanism by which phytoremediation systems promote hydrocarbon degradation in soil. The composition and degradation capacity of the bulk soil microbial community during the phytoremediation of soil contaminated with aged hydrocarbons was assessed. In the bulk soil, the level of catabolic genes involved in hydrocarbon degradation (ndoB, alkB, and xylE) as well as the mineralization of hexadecane and phenanthrene was higher in planted treatment cells than in treatment cells with no plants. There was no detectable shift in the 16S ribosomal DNA (rDNA) composition of the bulk soil community between treatments, but there were plant-specific and -selective effects on specific catabolic gene prevalence. Tall Fescue (Festuca arundinacea) increased the prevalence of ndoB, alkB, and xylE as well as naphthalene mineralization in rhizosphere soil compared to that in bulk soil. In contrast, Rose Clover (Trifolium hirtum) decreased catabolic gene prevalence and naphthalene mineralization in rhizosphere soil. The results demonstrated that phytoremediation systems increase the catabolic potential of rhizosphere soil by altering the functional composition of the microbial community. This change in composition was not detectable by 16S rDNA but was linked to specific functional genotypes with relevance to petroleum hydrocarbon degradation.
本研究的目的是探究植物修复系统促进土壤中碳氢化合物降解的机制。评估了老化碳氢化合物污染土壤植物修复过程中整体土壤微生物群落的组成和降解能力。在整体土壤中，种植处理单元中参与碳氢化合物降解的分解代谢基因（ndoB、alkB和xylE）水平以及十六烷和菲的矿化程度高于无植物的处理单元。处理之间整体土壤群落的16S核糖体DNA（rDNA）组成没有可检测到的变化，但对特定分解代谢基因的流行存在植物特异性和选择性影响。与整体土壤相比，高羊茅（Festuca arundinacea）增加了根际土壤中ndoB、alkB和xylE的流行率以及萘的矿化。相反，玫瑰三叶草（Trifolium hirtum）降低了根际土壤中分解代谢基因的流行率和萘的矿化。结果表明，植物修复系统通过改变微生物群落的功能组成来提高根际土壤的分解代谢潜力。这种组成变化通过16S rDNA无法检测到，但与与石油碳氢化合物降解相关的特定功能基因型有关。
