Muratova A, Hūbner Th, Tischer S, Turkovskaya O, Möder M, Kuschk P
Institute of Biochemistry and Physiology of Plants and Microorganisms, RAS, 13 Pr. Entuziastov, 410049 Saratov, Russia.
Int J Phytoremediation. 2003;5(2):137-51. doi: 10.1080/713610176.
The capability of plants to promote the microbial degradation of pollutants in rhizosphere soil is a principal mechanism of phytoremediation of PAH-contaminated soil. The formation of a specific rhizosphere microbocenosis with a high degradative potential toward contaminants is largely determined by plant species. The comparative PAH-degradation in unplanted soil and in soil planted with reed (Phragmites australis) and alfalfa (Medicago sativa) was studied in pot experiments during 2 years. Both alfalfa and reed successfully remediated contaminated soil by degrading 74.5 and 68.7% of PAHs, respectively. The study of the rhizosphere, rhizoplane, and unplanted-soil microflora in experimental pots showed that alfalfa stimulated the rhizosphere microflora of PAH-contaminated soil more effectively than did reed. Alfalfa clearly enhanced both the total number of microorganisms (1.3 times, according to fluorescence microscopy data) and the rate of the PAH-degrading population (almost seven times, according to plate counting). The degradative potential of its rhizosphere microflora toward PAHs was higher than the degradative activity of the reed rhizosphere. This study provides relevant information for the successful application of alfalfa to phytoremediate PAH-contaminated soil.
植物促进根际土壤中污染物微生物降解的能力是多环芳烃污染土壤植物修复的主要机制。具有高污染物降解潜力的特定根际微生物群落的形成在很大程度上取决于植物种类。在两年的盆栽实验中，研究了未种植土壤以及种植芦苇（Phragmites australis）和苜蓿（Medicago sativa）的土壤中多环芳烃的降解情况。苜蓿和芦苇都通过分别降解74.5%和68.7%的多环芳烃成功修复了污染土壤。对实验盆栽中根际、根面和未种植土壤微生物区系的研究表明，苜蓿比芦苇更有效地刺激了多环芳烃污染土壤的根际微生物区系。苜蓿明显增加了微生物总数（根据荧光显微镜数据增加了1.3倍）以及多环芳烃降解菌群的速率（根据平板计数几乎增加了7倍）。其根际微生物区系对多环芳烃的降解潜力高于芦苇根际的降解活性。本研究为苜蓿成功应用于多环芳烃污染土壤的植物修复提供了相关信息。
