Laroche Elia, Casiot Corinne, Fernandez-Rojo Lidia, Desoeuvre Angélique, Tardy Vincent, Bruneel Odile, Battaglia-Brunet Fabienne, Joulian Catherine, Héry Marina
HydroSciences Montpellier, CNRS, IRD, University of Montpellier, Montpellier, France.
BRGM, Geomicrobiology and Environmental Monitoring Unit, Orléans, France.
Front Microbiol. 2018 Dec 21;9:3169. doi: 10.3389/fmicb.2018.03169. eCollection 2018.
Passive treatment based on iron biological oxidation is a promising strategy for Arsenic (As)-rich acid mine drainage (AMD) remediation. In the present study, we characterized by 16S rRNA metabarcoding the bacterial diversity in a field-pilot bioreactor treating extremely As-rich AMD , over a 6 months monitoring period. Inside the bioreactor, the bacterial communities responsible for iron and arsenic removal formed a biofilm ("biogenic precipitate") whose composition varied in time and space. These communities evolved from a structure at first similar to the one of the feed water used as an inoculum to a structure quite similar to the natural biofilm developing in the AMD. Over the monitoring period, iron-oxidizing bacteria always largely dominated the biogenic precipitate, with distinct populations (), whose relative proportions extensively varied among time and space. A spatial structuring was observed inside the trays (arranged in series) composing the bioreactor. This spatial dynamic could be linked to the variation of the physico-chemistry of the AMD water between the raw water entering and the treated water exiting the pilot. According to redundancy analysis (RDA), the following parameters exerted a control on the bacterial communities potentially involved in the water treatment process: dissolved oxygen, temperature, pH, dissolved sulfates, arsenic and Fe(II) concentrations and redox potential. Appreciable arsenite oxidation occurring in the bioreactor could be linked to the stable presence of two distinct monophylogenetic groups of related bacteria. The ubiquity and the physiological diversity of the bacteria identified, as well as the presence of bacteria of biotechnological relevance, suggested that this treatment system could be applied to the treatment of other AMD.
基于铁生物氧化的被动处理是修复富含砷（As）的酸性矿山排水（AMD）的一种有前景的策略。在本研究中，我们通过16S rRNA宏条形码技术对一个处理极富含砷AMD的中试规模生物反应器内的细菌多样性进行了为期6个月的监测。在生物反应器内部，负责去除铁和砷的细菌群落形成了一种生物膜（“生物成因沉淀”），其组成随时间和空间而变化。这些群落从最初类似于用作接种物的进水的结构演变为与AMD中自然形成的生物膜非常相似的结构。在监测期间，铁氧化细菌在生物成因沉淀中始终占据主导地位，有不同的种群，其相对比例在时间和空间上有很大变化。在构成生物反应器的（串联排列的）托盘内部观察到了空间结构。这种空间动态可能与中试进水和出水之间AMD水的物理化学变化有关。根据冗余分析（RDA），以下参数对可能参与水处理过程的细菌群落产生控制作用：溶解氧、温度、pH值、溶解硫酸盐、砷和Fe（II）浓度以及氧化还原电位。生物反应器中发生的明显亚砷酸盐氧化可能与两个不同的单系相关细菌群的稳定存在有关。所鉴定细菌的普遍性和生理多样性，以及具有生物技术相关性的细菌的存在，表明该处理系统可应用于其他AMD的处理。
