Laboratório de Hidrobiologia, Instituto de Ciências Biomédicas de Abel Salazar (ICBAS-UP), Universidade do Porto, Largo Professor Abel Salazar, no. 2, 4099-003, Porto, Portugal.
Biodegradation. 2011 Jul;22(4):729-39. doi: 10.1007/s10532-010-9446-9. Epub 2010 Dec 25.
Estuaries are often considered sinks for contaminants and the cleanup of salt marshes, sensitive ecosystems with a major ecological role, should be carried out by means of least intrusive approaches, such as bioremediation. This study was designed to evaluate the influence of plant-microorganisms associations on petroleum hydrocarbons fate in salt marshes of a temperate estuary (Lima River, NW Portugal). Sediments un-colonized and colonized (rhizosediments) by different plants (Juncus maritimus, Phragmites australis, Triglochin striata and Spartina patens) were sampled in four sites of the lower and middle estuary for hydrocarbon degrading microorganisms (HD), total cell counts (TCC) and total petroleum hydrocarbons (TPHs) assessment. In general, TPHs, HD and TCC were significantly higher (P < 0.05) in rhizosediments than in un-colonized sediments. Also recorded were differences on the abundance of hydrocarbon degraders among the rhizosediment of the different plants collected at the same site (J. maritimus < P. australis < T. striata), with statistically significant differences (P < 0.05) between J. maritimus and T. striata. Moreover, strong positive correlations-0.81 and 0.84 (P < 0.05), between biotic (HD) and abiotic (organic matter content) parameters and TPHs concentrations were also found. Our data clearly suggest that salt marsh plants can influence the microbial community, by fostering the development of hydrocarbon-degrading microbial populations in its rhizosphere, an effect observed for all plants. This effect, combined with the plant capability to retain hydrocarbons around the roots, points out that salt marsh plant-microorganisms associations may actively contribute to hydrocarbon removal and degradation in estuarine environments.
河口通常被认为是污染物的汇，而盐沼作为具有重要生态作用的敏感生态系统，其清理工作应该采用最具侵入性的方法，如生物修复。本研究旨在评估植物-微生物联合体对温带河口（葡萄牙西北部利马河）盐沼中石油烃命运的影响。在河口下游和中游的四个地点，采集了未被植物（盐角草、芦苇、灯芯草和互花米草）和被植物（根际沉积物）殖民的沉积物，以评估烃类降解微生物（HD）、总细胞计数（TCC）和总石油烃（TPH）。一般来说，TPH、HD 和 TCC 在根际沉积物中明显高于未被殖民的沉积物（P < 0.05）。还记录了在同一地点采集的不同植物的根际沉积物中烃类降解菌的丰度存在差异（盐角草<芦苇<灯芯草），且存在统计学差异（P < 0.05），盐角草和灯芯草之间存在差异。此外，生物（HD）和非生物（有机质含量）参数与 TPH 浓度之间还存在强烈的正相关关系（P < 0.05），相关系数分别为 0.81 和 0.84。我们的数据清楚地表明，盐沼植物可以通过促进其根际中烃类降解微生物种群的发展来影响微生物群落，所有植物都观察到了这种影响。这种效应，加上植物在根周围保留烃类的能力，表明盐沼植物-微生物联合体可能积极有助于河口环境中烃类的去除和降解。
