Calderer M, Martí V, de Pablo J, Guivernau M, Prenafeta-Boldú F X, Viñas M
CTM Technological Centre, Environmental Technology Area, Plaça de la Ciència, No. 2, E-08243 Manresa, Spain.
CTM Technological Centre, Environmental Technology Area, Plaça de la Ciència, No. 2, E-08243 Manresa, Spain; Technical University of Catalonia, Department of Chemical Engineering (UPC, ETSEIB), Av. Diagonal, No. 647, E-08028 Barcelona, Spain.
Chemosphere. 2014 Sep;111:112-9. doi: 10.1016/j.chemosphere.2014.03.033. Epub 2014 Apr 19.
Enhanced heterotrophic denitrification by adding glucose was investigated by means of a soil column experiment which simulated the groundwater flow. The carbon-to-nitrogen ratio was the main factor determining denitrification potential under experimental conditions. The influence of stimulated denitrification on the autochthonous microbial community was investigated by quantitative PCR (qPCR), and denaturing gradient gel electrophoresis (DGGE). The qPCR detection of the nosZ genes encoding nitrous oxide reductase, and the comparison of the abundances of 16S rRNA genes revealed that the addition of glucose enhanced denitrification leading to an increase in both the total eubacteria and, in particular, in the ratio of denitrifying bacteria, which represented the 21% of the total native eubacteria on the basis of nosZ/16S rRNA gene ratio. Microbial community profiling by DGGE indicated that ribotypes closely related to the genera Acidovorax and Hydrogenophaga (Comamonadaceae family) became enriched in the soil column. The effects of biomass occurrence in the column system on soil hydrodynamics, assessed by tracer studies, revealed a reduction of porosity and a significant increase of dispersivity that could be caused by the appearance of new functional microbial biomass in the aquifer material under enhanced denitrifying conditions. The importance of investigating the microbial growth in relation to the hydrodynamic effects, during enhanced denitrification, has been revealed in the column system experiments associated with the bioremediation. Combining microbial characterisation and hydrodynamic data in a soil column system permits us to gain an insight to the limiting factors of different stimulation strategies that can be applied in the field.
通过模拟地下水流的土柱实验研究了添加葡萄糖对异养反硝化作用的增强效果。碳氮比是实验条件下决定反硝化潜力的主要因素。通过定量聚合酶链反应（qPCR）和变性梯度凝胶电泳（DGGE）研究了刺激反硝化对本地微生物群落的影响。对编码氧化亚氮还原酶的nosZ基因进行qPCR检测，并比较16S rRNA基因丰度，结果表明添加葡萄糖增强了反硝化作用，导致总真细菌数量增加，尤其是反硝化细菌的比例增加，根据nosZ/16S rRNA基因比例，反硝化细菌占本地总真细菌的21%。通过DGGE进行的微生物群落分析表明，与嗜酸菌属和嗜氢菌属（丛毛单胞菌科）密切相关的核糖型在土柱中富集。通过示踪研究评估柱系统中生物量的存在对土壤水动力的影响，结果表明孔隙率降低，弥散率显著增加，这可能是由于在增强反硝化条件下含水层材料中出现了新的功能性微生物生物量所致。在与生物修复相关的柱系统实验中，揭示了在增强反硝化过程中研究微生物生长与水动力效应关系的重要性。在土柱系统中将微生物表征与水动力数据相结合，使我们能够深入了解可应用于现场的不同刺激策略的限制因素。
