Laboratory of Environmental Remediation, College of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, People's Republic of China.
Environ Technol. 2014 Jan-Feb;35(1-4):514-20. doi: 10.1080/09593330.2013.836549.
Though phytoremediation has been widely used to restore various contaminated sites, it is still unclear how soil microbial communities respond microecologically to plants and pollutants during the process. In this paper, batch microcosms imitating in situ phytoremediation of petroleum-contaminated wetland by Scirpus triqueter were set up to monitor the influence of plant rhizosphere effect on soil microbes. Palmitic acid, one of the main root exudates of S. triqueter, was added to strengthen rhizosphere effect. Abundances of certain microbial subgroups were quantified by phospholipid fatty acid profiles. Results showed that diesel removal extents were significantly higher in the rhizosphere (57.6 +/-4.2-65.5 +/- 6.9%) than those in bulk soil (27.8 +/-6.5-36.3 +/- 3.2%). In addition, abundances of saturated, monounsaturated, and polyunsaturated fatty acids were significantly higher (P < 0.05) in planted soil than those in the bulk soil. When it was less than 15,000 mg diesel kg soil-1, increasing diesel concentration led to higher abundances of fungi, Gram-positive and Gram-negative bacteria. The addition of palmitic acid amplified the rhizosphere effect on soil microbial populations and diesel removal. Principal component analysis revealed that plant rhizosphere effect was the dominant factor affecting microbial structure. These results provided new insights into plant-microbe-pollutant coactions responsible for diesel degradation, and they were valuable to facilitate phytoremediation of diesel contamination in wetland habitats.
尽管植物修复已被广泛用于修复各种污染场地，但目前仍不清楚土壤微生物群落如何在植物和污染物存在的情况下在微观生态上对其做出响应。本文通过设置批量微宇宙模拟了香蒲原位修复石油污染湿地的过程，以监测植物根际效应对土壤微生物的影响。添加植物香蒲的主要根分泌物之一棕榈酸，以增强根际效应。通过磷脂脂肪酸谱定量了某些微生物亚群的丰度。结果表明，根际（57.6 +/-4.2-65.5 +/- 6.9%）中柴油的去除程度明显高于体相土壤（27.8 +/-6.5-36.3 +/- 3.2%）。此外，种植土壤中饱和、单不饱和和多不饱和脂肪酸的丰度明显高于体相土壤（P < 0.05）。当柴油浓度低于 15000 mg kg-1 时，增加柴油浓度会导致真菌、革兰氏阳性菌和革兰氏阴性菌的丰度增加。添加棕榈酸放大了根际对土壤微生物种群和柴油去除的影响。主成分分析表明，植物根际效应是影响微生物结构的主要因素。这些结果为植物-微生物-污染物相互作用对柴油降解的作用提供了新的见解，这对于促进湿地生境中柴油污染的植物修复具有重要意义。
