School of Biosciences, The University of Melbourne, Melbourne, VIC, Australia.
Melbourne Cytometry Platform, Melbourne Dental School, The University of Melbourne, Melbourne, VIC, Australia.
ISME J. 2021 Jul;15(7):2028-2042. doi: 10.1038/s41396-021-00902-4. Epub 2021 Feb 8.
Corals house a variety of microorganisms which they depend on for their survival, including endosymbiotic dinoflagellates (Symbiodiniaceae) and bacteria. While cnidarian-microorganism interactions are widely studied, Symbiodiniaceae-bacteria interactions are only just beginning to receive attention. Here, we describe the localization and composition of the bacterial communities associated with cultures of 11 Symbiodiniaceae strains from nine species and six genera. Three-dimensional confocal laser scanning and electron microscopy revealed bacteria are present inside the Symbiodiniaceae cells as well as closely associated with their external cell surface. Bacterial pure cultures and 16S rRNA gene metabarcoding from Symbiodiniaceae cultures highlighted distinct and highly diverse bacterial communities occur intracellularly, closely associated with the Symbiodiniaceae outer cell surface and loosely associated (i.e., in the surrounding culture media). The intracellular bacteria are highly conserved across Symbiodiniaceae species, suggesting they may be involved in Symbiodiniaceae physiology. Our findings provide unique new insights into the biology of Symbiodiniaceae.
珊瑚体内栖息着多种微生物，珊瑚依赖这些微生物生存，其中包括内共生的甲藻（虫黄藻科）和细菌。虽然刺胞动物与微生物的相互作用已得到广泛研究，但有关虫黄藻与细菌相互作用的研究才刚刚开始受到关注。在这里，我们描述了与来自九个属和六个属的 11 个虫黄藻菌株的培养物相关的细菌群落的定位和组成。三维共聚焦激光扫描和电子显微镜显示，细菌存在于虫黄藻细胞内以及其外部细胞表面附近。从虫黄藻培养物中分离的细菌纯培养物和 16S rRNA 基因宏条形码突出显示了在细胞内、与虫黄藻外细胞表面紧密相关以及松散相关（即在周围培养基中）存在着独特且高度多样化的细菌群落。细胞内细菌在虫黄藻物种间高度保守，表明它们可能参与虫黄藻的生理机能。我们的研究结果为虫黄藻的生物学提供了独特的新见解。
