Department of Biological Sciences, Faculty of Science, Kuwait University, Kuwait.
Ecotoxicol Environ Saf. 2010 Nov;73(8):1998-2003. doi: 10.1016/j.ecoenv.2010.08.033. Epub 2010 Sep 15.
The rhizospheric soils of three tested legume crops: broad beans (Vicia faba), beans (Phaseolus vulgaris) and pea (Pisum sativum), and two nonlegume crops: cucumber (Cucumis sativus) and tomato, (Lycopersicon esculentum) contained considerable numbers (the magnitude of 10(5)g(-1) soil) of bacteria with the combined potential for hydrocarbon-utilization and mercury-resistance. Sequencing of the 16S rRNA coding genes of rhizobacteria associated with broad beans revealed that they were affiliated to Citrobacter freundii, Enterobacter aerogenes, Exiquobacterium aurantiacum, Pseudomonas veronii, Micrococcus luteus, Brevibacillus brevis, Arthrobacter sp. and Flavobacterium psychrophilum. These rhizobacteria were also diazotrophic, i.e. capable of N(2) fixation, which makes them self-sufficient regarding their nitrogen nutrition and thus suitable remediation agents in nitrogen-poor soils, such as the oily desert soil. The crude oil attenuation potential of the individual rhizobacteria was inhibited by HgCl(2), but about 50% or more of this potential was still maintained in the presence of up to 40 mgl(-1) HgCl(2). Rhizobacteria-free plants removed amounts of mercury from the surrounding media almost equivalent to those removed by the rhizospheric bacterial consortia in the absence of the plants. It was concluded that both the collector plants and their rhizospheric bacterial consortia contributed equivalently to mercury removal from soil.
三种测试豆科作物（蚕豆、菜豆和豌豆）和两种非豆科作物（黄瓜和番茄）的根际土壤中含有大量（数量级为 10(5)g(-1)土壤）具有烃类利用和汞抗性综合潜力的细菌。与蚕豆相关的根际细菌的 16S rRNA 编码基因测序表明，它们与柠檬酸杆菌、产气肠杆菌、橙色黄杆菌、荧光假单胞菌、微球菌、短芽孢杆菌、节杆菌和嗜冷黄杆菌有关。这些根际细菌也是固氮的，即能够进行 N2 固定，这使得它们在氮素贫瘠的土壤中，如含油沙漠土壤中，能够自给自足的获取氮素营养，因此是合适的修复剂。HgCl2 抑制了单个根际细菌的原油衰减潜力，但在存在高达 40 mgl(-1)HgCl2 的情况下，仍保持了约 50%或更多的潜力。无植物的根际细菌从周围介质中去除的汞量几乎与植物不存在时根际细菌群落从周围介质中去除的汞量相等。结论是，集汞植物及其根际细菌群落都为土壤中汞的去除做出了同等贡献。
