Zhou Jin, Richlen Mindy L, Sehein Taylor R, Kulis David M, Anderson Donald M, Cai Zhonghua
Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China.
Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, United States.
Front Microbiol. 2018 Jun 6;9:1201. doi: 10.3389/fmicb.2018.01201. eCollection 2018.
Interactions between microorganisms and algae during bloom events significantly impacts their physiology, alters ambient chemistry, and shapes ecosystem diversity. The potential role these interactions have in bloom development and decline are also of particular interest given the ecosystem impacts of algal blooms. We hypothesized that microbial community structure and succession is linked to specific bloom stages, and reflects complex interactions among taxa comprising the phycosphere environment. This investigation used pyrosequencing and correlation approaches to assess patterns and associations among bacteria, archaea, and microeukaryotes during a spring bloom of the dinoflagellate . Within the bacterial community, and were predominant during the initial bloom stage, while , and were the most abundant taxa present during bloom onset and termination. In the archaea biosphere, methanogenic members were present during the early bloom period while the majority of species identified in the late bloom stage were ammonia-oxidizing archaea and . Dinoflagellates were the major eukaryotic group present during most stages of the bloom, whereas a mixed assemblage comprising diatoms, green-algae, rotifera, and other microzooplankton were present during bloom termination. Temperature and salinity were key environmental factors associated with changes in bacterial and archaeal community structure, respectively, whereas inorganic nitrogen and inorganic phosphate were associated with eukaryotic variation. The relative contribution of environmental parameters measured during the bloom to variability among samples was 35.3%. Interaction analysis showed that Maxillopoda, Spirotrichea, Dinoflagellata, and were keystone taxa within the positive-correlation network, while , Dictyochophyceae, Mamiellophyceae, and were the main contributors to the negative-correlation network. The positive and negative relationships were the primary drivers of mutualist and competitive interactions that impacted algal bloom fate, respectively. Functional predictions showed that blooms enhance microbial carbohydrate and energy metabolism, and alter the sulfur cycle. Our results suggest that microbial community structure is strongly linked to bloom progression, although specific drivers of community interactions and responses are not well understood. The importance of considering biotic interactions (e.g., competition, symbiosis, and predation) when investigating the link between microbial ecological behavior and an algal bloom's trajectory is also highlighted.
水华事件期间微生物与藻类之间的相互作用会显著影响它们的生理机能，改变周围环境的化学性质，并塑造生态系统的多样性。鉴于藻华对生态系统的影响，这些相互作用在水华发展和衰退过程中所起的潜在作用也备受关注。我们假设微生物群落结构和演替与特定的水华阶段相关联，并且反映了构成藻际环境的各类群之间的复杂相互作用。本研究采用焦磷酸测序和相关性分析方法，评估在甲藻春季水华期间细菌、古菌和微型真核生物之间的模式和关联。在细菌群落中，[具体细菌名称1]和[具体细菌名称2]在水华初期阶段占主导地位，而[具体细菌名称3]、[具体细菌名称4]和[具体细菌名称5]是水华开始和结束时数量最多的类群。在古菌生物圈内，产甲烷成员在水华早期出现，而在水华后期鉴定出的大多数物种是氨氧化古菌和[具体古菌名称]。甲藻是水华大多数阶段存在的主要真核生物类群，而在水华结束时出现了由硅藻、绿藻、轮虫和其他微型浮游动物组成的混合群落。温度和盐度分别是与细菌和古菌群落结构变化相关的关键环境因素，而无机氮和无机磷酸盐与真核生物的变化相关。水华期间测量的环境参数对样本间变异性的相对贡献为35.3%。相互作用分析表明，颚足纲、旋毛纲、甲藻纲和[具体分类单元1]是正相关网络中的关键类群，而[具体分类单元2]、硅藻纲、小球藻纲和[具体分类单元3]是负相关网络的主要贡献者。正相关和负相关关系分别是影响藻华命运的互利和竞争相互作用的主要驱动因素。功能预测表明，水华增强了微生物的碳水化合物和能量代谢，并改变了硫循环。我们的结果表明，微生物群落结构与水华进程密切相关，尽管群落相互作用和反应的具体驱动因素尚不清楚。同时也强调了在研究微生物生态行为与藻华轨迹之间的联系时考虑生物相互作用（如竞争、共生和捕食）的重要性。
