Biodegradation is responsible for most contaminant removal in plumes of organic compounds and is fastest at the plume fringe where microbial cell numbers and activity are highest. As the plume migrates from the source, groundwater containing the contaminants and planktonic microbial community encounters uncontaminated substrata on which an attached community subsequently develops. While attached microbial communities are important for biodegradation, the time needed for their establishment, their relationship with the planktonic community and the processes controlling their development are not well understood. We compare the dynamics of development of attached microbial communities on sterile substrata in the field and laboratory microcosms, sampled simultaneously at intervals over two years. We show that attached microbial cell numbers increased rapidly and stabilised after similar periods of incubation (∼100 days) in both field and microcosm experiments. These timescales were similar even though variation in the contaminant source evident in the field was absent in microcosm studies, implying that this period was an emergent property of the attached microbial community. 16S rRNA gene sequencing showed that attached and planktonic communities differed markedly, with many attached organisms strongly preferring attachment. Successional processes were evident, both in community diversity indices and from community network analysis. Community development was governed by both deterministic and stochastic processes and was related to the predilection of community members for different lifestyles and the geochemical environment.

生物降解是去除有机化合物羽流中大多数污染物的原因，在微生物细胞数量和活性最高的羽流边缘最快。当羽流从源头迁移时，含有污染物的地下水和浮游微生物群落会遇到未受污染的地层，随后会在其上形成附着的群落。虽然附着的微生物群落对于生物降解很重要，但建立微生物所需要的时间，它们与浮游生物的关系以及控制其发育的过程尚未得到很好的了解。我们比较了在现场和实验室微观世界上无菌基质上附着的微生物群落的发展动态，在两年的时间间隔内同时进行了采样。我们显示，在田野和微观实验中，经过相似的潜伏期（约100天）后，附着的微生物细胞数量迅速增加并稳定下来。这些时间尺度是相似的，即使在微观研究中没有在现场发现的明显污染源变化时，也暗示了这一时期是附属微生物群落的新兴特性。16S rRNA基因测序表明，附着和浮游生物群落显着不同，许多附着生物强烈喜欢附着。从社区多样性指数和社区网络分析来看，演替过程都很明显。社区发展既受确定性过程也受随机过程支配，并且与社区成员对不同生活方式和地球化学环境的偏爱有关。