Zhu Zhu, Meng Rui, Smith Walker O, Doan-Nhu Hai, Nguyen-Ngoc Lam, Jiang Xinjun
School of Oceanography, Shanghai Jiao Tong University, Shanghai, China.
Vietnam Academy of Science and Technology, Institute of Oceanography, Nha Trang, Vietnam.
Front Microbiol. 2021 Sep 17;12:737484. doi: 10.3389/fmicb.2021.737484. eCollection 2021.
The cosmopolitan algae forms harmful algal blooms frequently in a number of tropical and subtropical coastal regions in the past two decades. During the bloom, the giant colony, which is formed by , is the dominant morphotype. However, the microenvironment and the microbial composition in the intracolonial fluid are poorly understood. Here, we used high-throughput 16S rRNA amplicon sequencing to examine the bacterial composition and predicted functions in intracolonial fluid. Compared with the bacterial consortia in ambient seawater, intracolonial fluids possessed the lower levels of microbial richness and diversity, implying selectivity of bacteria by the unique intracolonial microenvironment enclosed within the polysaccharide envelope. The bacterial consortia in intracolonial fluid were dominated by (48.6% of total abundance) and (28.5%). The bacteria and microbial function enriched in intracolonial fluid were involved in aromatic benzenoid compounds degradation, DMSP and DMS production and consumption, and antibacterial compounds synthesis. We suggest that the colonial envelope allows for the formation of a specific microenvironment; thus, the unique microbial consortia inhabiting intracolonial fluid has close interaction with cells, which may benefit colony development.
在过去二十年中，这种世界性的藻类在许多热带和亚热带沿海地区频繁形成有害藻华。在藻华期间，由[具体成分]形成的巨大群体是主要的形态类型。然而，人们对群体内液体中的微环境和微生物组成了解甚少。在此，我们使用高通量16S rRNA扩增子测序来检测群体内液体中的细菌组成和预测功能。与周围海水中的细菌群落相比，群体内液体中的微生物丰富度和多样性水平较低，这意味着被多糖包膜包围的独特群体内微环境对细菌具有选择性。群体内液体中的细菌群落以[具体细菌1]（占总丰度的48.6%）和[具体细菌2]（占28.5%）为主。群体内液体中富集的细菌和微生物功能涉及芳香类苯化合物降解、二甲基巯基丙酸内盐（DMSP）和二甲基硫（DMS）的产生与消耗以及抗菌化合物的合成。我们认为，[藻类名称]的群体包膜允许形成特定的微环境；因此，栖息在群体内液体中的独特微生物群落与[藻类名称]细胞有密切相互作用，这可能有利于群体发育。
