Department of Microbiology, Radboud University, Nijmegen, The Netherlands.
Leibniz Institute DSMZ, Braunschweig, Germany.
Environ Microbiol. 2021 Mar;23(3):1379-1396. doi: 10.1111/1462-2920.15341. Epub 2021 Jan 12.
Waterbodies such as lakes and ponds are fragile environments affected by human influences. Suitable conditions can result in massive growth of phototrophs, commonly referred to as phytoplankton blooms. Such events benefit heterotrophic bacteria able to use compounds secreted by phototrophs or their biomass as major nutrient source. One example of such bacteria are Planctomycetes, which are abundant on the surfaces of marine macroscopic phototrophs; however, less data are available on their ecological roles in limnic environments. In this study, we followed a cultivation-independent deep sequencing approach to study the bacterial community composition during a cyanobacterial bloom event in a municipal duck pond. In addition to cyanobacteria, which caused the bloom event, members of the phylum Planctomycetes were significantly enriched in the cyanobacteria-attached fraction compared to the free-living fraction. Separate datasets based on isolated DNA and RNA point towards considerable differences in the abundance and activity of planctomycetal families, indicating different activity peaks of these families during the cyanobacterial bloom. Motivated by the finding that the sampling location harbours untapped bacterial diversity, we included a complementary cultivation-dependent approach and isolated and characterized three novel limnic strains belonging to the phylum Planctomycetes.
水体，如湖泊和池塘，是受到人类影响的脆弱环境。合适的条件会导致光养生物（通常称为浮游植物水华）大量生长。这种事件有利于能够利用光养生物分泌的化合物或其生物质作为主要营养源的异养细菌。此类细菌的一个例子是浮霉菌门，它们在海洋宏观光养生物的表面大量存在；然而，关于它们在淡水环境中的生态作用的数据较少。在这项研究中，我们采用了一种非培养的深度测序方法，来研究市政鸭塘中蓝藻水华事件期间的细菌群落组成。与自由生活的浮游细菌相比，与蓝藻附着的浮游细菌相比，门浮霉菌门的成员在蓝藻附着的浮游细菌中明显富集。基于分离的 DNA 和 RNA 的单独数据集表明，浮霉科的丰度和活性存在相当大的差异，表明这些科在蓝藻水华期间有不同的活性高峰。由于发现采样地点蕴藏着未开发的细菌多样性，我们采用了一种补充的培养依赖方法，并分离和鉴定了属于浮霉菌门的三个新的淡水菌株。
