Department of Biosystems Engineering and Soil Science, The University of Tennessee, Knoxville, TN, 37996, USA.
Department of Microbiology, The University of Tennessee, Knoxville, TN, 37996, USA.
Environ Microbiol. 2019 Jun;21(6):2043-2055. doi: 10.1111/1462-2920.14566. Epub 2019 Mar 28.
The delivery of fermentable substrate(s) to subsurface environments stimulates Fe(III)-bioreduction and achieves detoxification of organic/inorganic contaminants. Although, much research has been conducted on the microbiology of such engineered systems at lab and field scales, little attention has been given to the phage-host interactions and virus community dynamics in these environments. The objective was to determine the responses of soil bacterial communities and viral assemblages to stimulated anaerobic Fe(III)-bioreduction following electron donor (e.g. acetate) addition. Microbial communities, including viral assemblages, were investigated after 60 days of Fe(III)-bioreduction in laboratory-scale columns continuously fed with acetate-amended artificial groundwater. Viral abundances were greatest in the influent section and decreased along the flow path. Acetate availability was important in influencing bacterial diversity, microbial interactions and viral abundance and community composition. The impact of acetate addition was most evident in the influent section of the columns. The increased relative abundance of Fe(III)-reducing bacteria coincided with an increase in viral abundance in areas of the columns exhibiting the most Fe(III) reduction. The genetic composition of viruses in these column sections also differed from the control column and distal sections of acetate-treated columns suggesting viral communities responded to biostimulated Fe(III)-bioreduction.
向地下环境中输送可发酵的基质（s）会刺激 Fe(III)-生物还原，并实现有机/无机污染物的解毒。尽管已经在实验室和现场规模上对这些工程系统的微生物学进行了大量研究，但对于这些环境中的噬菌体-宿主相互作用和病毒群落动态，关注甚少。本研究的目的是确定在添加电子供体（例如乙酸盐）后，土壤细菌群落和病毒组合对受刺激的厌氧 Fe(III)-生物还原的响应。在实验室规模的连续用乙酸盐修饰的人工地下水进料的柱中进行 60 天的 Fe(III)-生物还原后，研究了微生物群落，包括病毒组合。病毒丰度在入口段最高，并沿流动路径下降。乙酸盐的可用性对细菌多样性、微生物相互作用和病毒丰度和群落组成有重要影响。乙酸盐添加的影响在柱的入口段最为明显。在表现出最多 Fe(III)还原的柱区域，随着病毒丰度的增加，Fe(III)-还原菌的相对丰度增加。这些柱段中的病毒的遗传组成也与对照柱和乙酸盐处理柱的远端段不同，表明病毒群落对生物刺激的 Fe(III)-生物还原有反应。
