Departamento de Biotecnología Marina, Centro de Investigación Científica y Educación Superior de Ensenada B.C., Ensenada, Mexico.
Department of Ecological Chemistry, Alfred-Wegener Institut, Helmholtz-Zentrum für Polar-und Meeresforschung, Bremerhaven, Germany.
PLoS One. 2024 Jul 16;19(7):e0306108. doi: 10.1371/journal.pone.0306108. eCollection 2024.
Interactions between bacterial microbiota and epibenthic species of the dinoflagellate Prorocentrum may define the onset and persistence of benthic harmful algal blooms (bHABs). Chemical ecological interactions within the dinoflagellate phycosphere potentially involve a complex variety of organic molecules, metabolites, and toxins, including undefined bioactive compounds. In this study, the bacterial diversity and core members of the dinoflagellate-associated microbiota were defined from 11 strains of three epibenthic Prorocentrum species, representing three geographically disjunct locations within Mexican coastal waters. Microbiota profiles in stable monoclonal Prorocentrum cultures were obtained by sequencing amplicons of the V3-V4 region of the 16S rRNA gene. Thirteen classes of bacteria were identified among dinoflagellate clones, where Alphaproteobacteria, Gammaproteobacteria, and Bacteroidia were consistently dominant. The bacterial community structure exhibited significantly different grouping by the location of origin of dinoflagellate clones. No significant diversity difference was found among free-living or unattached bacteria in the dinoflagellate culture medium (M) compared with those in closer association with the dinoflagellate host cells (H). Twelve taxa were defined as core members of the bacterial assemblage, representing the genera Algiphilus, Cohaesibacter, Labrenzia, Mameliella, Marinobacter, Marivita, Massilia, Muricauda, Roseitalea, and an unclassified member of the Rhodobacteraceae. The core members are inferred to significantly contribute to primary and secondary metabolic functions, but no direct correlation with dinoflagellate toxigenicity was apparent. Overall the bacterial profile and implied gene functionality indicated a suite of positive interactions, suggesting either mutualism or commensalism with the dinoflagellate. The further characterization and interpretation of specific gene functions and interactions between bacteria and dinoflagellates, such as epibenthic members of genus Prorocentrum, are key to understanding their role in toxigenesis and bHAB development.
细菌微生物群与甲藻属浮游生物之间的相互作用可能决定了底栖有害藻华（bHAB）的爆发和持续时间。甲藻藻球体内的化学生态相互作用可能涉及多种有机分子、代谢物和毒素，包括未定义的生物活性化合物。在这项研究中，从三种底栖甲藻属浮游生物的 11 个菌株中定义了甲藻相关微生物群的细菌多样性和核心成员，这些菌株代表了墨西哥沿海水域的三个地理位置。通过对 16S rRNA 基因 V3-V4 区域的扩增子进行测序，获得了稳定的单克隆甲藻培养物中的微生物组谱。在甲藻克隆中鉴定出 13 个细菌类群，其中α变形菌、γ变形菌和拟杆菌门始终占优势。根据甲藻克隆的起源地，细菌群落结构表现出明显不同的分组。与甲藻宿主细胞（H）更紧密相关的甲藻培养液（M）中的自由生活或无附着细菌与游离细菌相比，没有发现显著的多样性差异。12 个分类群被定义为细菌组合的核心成员，代表属 Alphaproteobacteria、Gammaproteobacteria 和 Bacteroidia。核心成员被推断为主要和次要代谢功能做出了重要贡献，但与甲藻的产毒力没有明显的相关性。总的来说，细菌谱和暗示的基因功能表明了一系列积极的相互作用，表明与甲藻共生或共栖。进一步表征和解释细菌与甲藻之间的特定基因功能和相互作用，例如属浮游生物成员，是理解它们在产毒和 bHAB 发展中的作用的关键。
