Lehmann Katja, Singer Andrew, Bowes Michael J, Ings Nicola L, Field Dawn, Bell Thomas
NERC Centre for Ecology & Hydrology, Wallingford, OX10 8BB, UK
NERC Centre for Ecology & Hydrology, Wallingford, OX10 8BB, UK.
FEMS Microbiol Ecol. 2015 Dec;91(12). doi: 10.1093/femsec/fiv129. Epub 2015 Oct 22.
Elevated nutrient levels can lead to excessive biofilm growth, but reducing nutrient pollution is often challenging. There is therefore interest in developing control measures for biofilm growth in nutrient-rich rivers that could act as complement to direct reductions in nutrient load. Shading of rivers is one option that can mitigate blooms, but few studies have experimentally examined the differences in biofilm communities grown under shaded and unshaded conditions. We investigated the assembly and diversity of biofilm communities using in situ mesocosms within the River Thames (UK). Biofilm composition was surveyed by 454 sequencing of 16S amplicons (∼400 bp length covering regions V6/V7). The results confirm the importance of sunlight for biofilm community assembly; a resource that was utilized by a relatively small number of dominant taxa, leading to significantly less diversity than in shaded communities. These differences between unshaded and shaded treatments were either because of differences in resource utilization or loss of diatom-structures as habitats for bacteria. We observed more co-occurrence patterns and network interactions in the shaded communities. This lends further support to the proposal that increased river shading can help mitigate the effects from macronutrient pollution in rivers.
营养水平升高会导致生物膜过度生长，但减少营养污染往往具有挑战性。因此，人们有兴趣开发针对营养丰富河流中生物膜生长的控制措施，作为直接减少营养负荷的补充。河流遮荫是一种可以减轻水华的选择，但很少有研究通过实验研究在有遮荫和无遮荫条件下生长的生物膜群落的差异。我们利用英国泰晤士河内的原位中宇宙研究了生物膜群落的组装和多样性。通过对16S扩增子（长度约400 bp，覆盖V6/V7区域）进行454测序来调查生物膜组成。结果证实了阳光对生物膜群落组装的重要性；阳光这种资源被相对少数的优势类群利用，导致其多样性明显低于有遮荫的群落。无遮荫和有遮荫处理之间的这些差异，要么是由于资源利用的差异，要么是作为细菌栖息地的硅藻结构的丧失。我们在有遮荫的群落中观察到更多的共现模式和网络相互作用。这进一步支持了增加河流遮荫有助于减轻河流中大量营养物质污染影响的提议。
