Ziegler Anja S, McIlroy Simon J, Larsen Poul, Albertsen Mads, Hansen Aviaja A, Heinen Nicolas, Nielsen Per Halkjær
Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark.
Alfa Laval Nakskov A/S, Nakskov, Denmark.
PLoS One. 2016 Jul 11;11(7):e0158811. doi: 10.1371/journal.pone.0158811. eCollection 2016.
Membrane fouling presents the greatest challenge to the application of membrane bioreactor (MBR) technology. Formation of biofilms on the membrane surface is the suggested cause, yet little is known of the composition or dynamics of the microbial community responsible. To gain an insight into this important question, we applied 16S rRNA gene amplicon sequencing with a curated taxonomy and fluorescent in situ hybridization to monitor the community of a pilot-scale MBR carrying out enhanced biological nitrogen and phosphorus removal with municipal wastewater. In order to track the dynamics of the fouling process, we concurrently investigated the communities of the biofilm, MBR bulk sludge, and the conventional activated sludge system used to seed the MBR system over several weeks from start-up. As the biofilm matured the initially abundant betaproteobacterial genera Limnohabitans, Hydrogenophaga and Malikia were succeeded by filamentous Chloroflexi and Gordonia as the abundant species. This study indicates that, although putative pioneer species appear, the biofilm became increasingly similar to the bulk community with time. This suggests that the microbial population in bulk water will largely determine the community structure of the mature biofilm.
膜污染是膜生物反应器（MBR）技术应用面临的最大挑战。膜表面生物膜的形成被认为是其原因，但对于负责的微生物群落的组成或动态却知之甚少。为了深入了解这个重要问题，我们应用了带有精心整理分类法的16S rRNA基因扩增子测序和荧光原位杂交技术，来监测一个中试规模的MBR中微生物群落，该MBR使用城市污水进行强化生物脱氮除磷。为了追踪污染过程的动态，我们在启动后的几周内，同时研究了生物膜、MBR混合污泥以及用于接种MBR系统的传统活性污泥系统中的微生物群落。随着生物膜的成熟，最初大量存在的β-变形菌属Limnohabitans、嗜氢菌属和马利基亚属被丝状绿弯菌属和戈登氏菌属取代，成为优势物种。这项研究表明，尽管出现了假定的先锋物种，但随着时间的推移，生物膜与混合污泥群落越来越相似。这表明，大量水体中的微生物种群将在很大程度上决定成熟生物膜的群落结构。
