Handley Kim M, Wrighton Kelly C, Miller Christopher S, Wilkins Michael J, Kantor Rose S, Thomas Brian C, Williams Kenneth H, Gilbert Jack A, Long Philip E, Banfield Jillian F
Earth & Planetary Science, University of California, Berkeley, CA, 94720, USA; Department of Ecology and Evolution, University of Chicago, Chicago, IL, 60637, USA.
Environ Microbiol. 2015 Mar;17(3):622-36. doi: 10.1111/1462-2920.12467. Epub 2014 Apr 18.
Microbial community structure, and niche and neutral processes can all influence response to disturbance. Here, we provide experimental evidence for niche versus neutral and founding community effects during a bioremediation-related organic carbon disturbance. Subsurface sediment, partitioned into 22 flow-through columns, was stimulated in situ by the addition of acetate as a carbon and electron donor source. This drove the system into a new transient biogeochemical state characterized by iron reduction and enriched Desulfuromonadales, Comamonadaceae and Bacteroidetes lineages. After approximately 1 month conditions favoured sulfate reduction, and were accompanied by a substantial increase in the relative abundance of Desulfobulbus, Desulfosporosinus, Desulfitobacterium and Desulfotomaculum. Two subsets of four to five columns each were switched from acetate to lactate amendment during either iron (earlier) or sulfate (later) reduction. Hence, subsets had significantly different founding communities. All lactate treatments exhibited lower relative abundances of Desulfotomaculum and Bacteroidetes, enrichments of Clostridiales and Psychrosinus species, and a temporal succession from highly abundant Clostridium sensu stricto to Psychrosinus. Regardless of starting point, lactate-switch communities followed comparable structural trajectories, whereby convergence was evident 9 to 16 days after each switch, and significant after 29 to 34 days of lactate addition. Results imply that neither the founding community nor neutral processes influenced succession following perturbation.
微生物群落结构、生态位和中性过程都会影响对干扰的响应。在此，我们提供了在与生物修复相关的有机碳干扰期间，生态位与中性以及初始群落效应的实验证据。将地下沉积物分成22个流通柱，通过添加醋酸盐作为碳源和电子供体源进行原位刺激。这使系统进入了一个以铁还原为特征的新的瞬态生物地球化学状态，并富集了脱硫单胞菌目、丛毛单胞菌科和拟杆菌谱系。大约1个月后，条件有利于硫酸盐还原，并伴随着脱硫球茎菌属、脱硫孢菌属、脱硫脱硫弧菌属和脱硫芽孢杆菌属相对丰度的大幅增加。在铁还原（较早）或硫酸盐还原（较晚）期间，将每组四到五个柱的两个子集从醋酸盐改为乳酸盐修正。因此，各子集具有显著不同的初始群落。所有乳酸盐处理均表现出较低的脱硫芽孢杆菌属和拟杆菌相对丰度，梭菌目和嗜冷单胞菌属物种的富集，以及从高丰度的严格意义上的梭菌到嗜冷单胞菌的时间演替。无论起点如何，乳酸盐转换群落都遵循可比的结构轨迹，即在每次转换后9至16天明显趋同，在添加乳酸盐29至34天后显著趋同。结果表明，初始群落和中性过程均未影响扰动后的演替。
