Laboratoire de Biosurveillance de l'Environnement, Faculté des Sciences de Bizerte, Bizerte, Tunisia,
Environ Sci Pollut Res Int. 2014 Mar;21(5):3670-9. doi: 10.1007/s11356-013-2330-5. Epub 2013 Nov 26.
A microcosm experiment was setup to examine (1) the effect of phenanthrene contamination on meiofauna and bacteria communities and (2) the effects of different bioremediation strategies on phenanthrene degradation and on the community structure of free-living marine nematodes. Sediments from Bizerte lagoon were contaminated with (100 mg kg(-1)) phenanthrene and effects were examined after 20 days. Biostimulation (addition of nitrogen and phosphorus fertilizer or mineral salt medium) and bioaugmentation (inoculation of a hydrocarbonoclastic bacterium) were used as bioremediation treatments. Bacterial biomass was estimated using flow cytometry. Meiofauna was counted and identified at the higher taxon level using a stereomicroscope. Nematodes, comprising approximately two thirds of total meiofauna abundance, were identified to genus or species. Phenanthrene contamination had a severe impact on bacteria and meiofauna abundances with a strong decrease of nematodes with a complete disappearance of polychaetes and copepods. Bioremediation counter balanced the toxic effects of phenanthrene since meiofauna and bacteria abundances were significantly higher (p < 0.01) than those observed in phenanthrene contamination. Up to 98 % of phenanthrene removal was observed. In response to phenanthrene contamination, the nematode species had different behavior: Daptonema fallax was eliminated in contaminated microcosms, suggesting that it is an intolerant species to phenanthrene; Neochromadora peocilosoma, Spirinia parasitifera, and Odontophora n. sp., which significantly (p < 0.05) increased in contaminated microcosms, could be considered as "opportunistic" species to phenanthrene whereas Anticoma acuminata and Calomicrolaimus honestus increased in the treatment combining biostimulation and bioaugmentation. Phenanthrene had a significant effect on meiofaunal and bacterial abundances (p < 0.05), with a strong reduction of density and change in the nematode communities. Biostimulation using mineral salt medium strongly enhanced phenanthrene removal, leading to a decrease of its toxicity. This finding opens exciting axes for the future use of biostimulation to reduce toxic effects of PAHs for meiofauna and bacteria in lagoon sediment.
（1）菲污染对小型底栖动物和细菌群落的影响，以及（2）不同生物修复策略对菲降解和自由生活海洋线虫群落结构的影响。比塞大泻湖的沉积物用菲（100mg/kg）污染，并在 20 天后检查效果。生物刺激（添加氮、磷肥料或无机盐培养基）和生物强化（接种烃降解细菌）被用作生物修复处理。使用流式细胞术估计细菌生物量。使用立体显微镜在较高分类群水平上计数和鉴定小型底栖动物。线虫占总小型底栖动物丰度的约三分之二，鉴定到属或种。菲污染对细菌和小型底栖动物丰度有严重影响，线虫数量强烈减少，多毛类和桡足类完全消失。生物修复平衡了菲的毒性效应，因为小型底栖动物和细菌丰度显著高于（p<0.01）污染组。观察到高达 98%的菲去除。对菲污染的响应，线虫物种表现出不同的行为：Daptonema fallax 在污染微宇宙中被消除，表明它是一种对菲不耐受的物种；Neochromadora peocilosoma、Spirinia parasitifera 和 Odontophora n. sp.，在污染微宇宙中显著（p<0.05）增加，可被认为是菲的“机会主义”物种，而 Anticoma acuminata 和 Calomicrolaimus honestus 在生物刺激和生物强化组合处理中增加。菲对小型底栖动物和细菌丰度有显著影响（p<0.05），密度强烈降低，线虫群落发生变化。使用无机盐培养基的生物刺激强烈增强了菲的去除，降低了其毒性。这一发现为未来利用生物刺激来减少泻湖沉积物中多环芳烃对小型底栖动物和细菌的毒性影响开辟了令人兴奋的方向。
