Changes in Free-Living and Particle-Associated Bacterial Communities Depending on the Growth Phases of Marine Green Algae, <i>Tetraselmis suecica</i>

• Main Authors: Bum Soo Park, Won-Ji Choi, Ruoyu Guo, Hansol Kim, Jang-Seu Ki
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Journal of Marine Science and Engineering
• Subjects: <i>Tetraselmis suecica</i>; associated bacterial community; free-living bacteria; particle associated bacteria
• Online Access: https://www.mdpi.com/2077-1312/9/2/171

Bacteria are remarkably associated with the growth of green algae <i>Tetraselmis</i> which are used as a feed source in aquaculture, but <i>Tetraselmis</i>-associated bacterial community is characterized insufficiently. Here, as a first step towards characterization of the associated bacteria, we investigated the community composition of free-living (FLB) and particle-associated (PAB) bacteria in each growth phase (lag, exponential, stationary, and death) of <i>Tetraselmis suecica</i> P039 culture using pyrosequencing. The percentage of shared operational taxonomic units (OTUs) between FLB and PAB communities was substantially high (≥92.4%), but their bacterial community compositions were significantly (<i>p</i> = 0.05) different from each other. The PAB community was more variable than the FLB community depending on the growth phase of <i>T. suecica</i>. In the PAB community, the proportions of <i>Marinobacter</i> and Flavobacteriaceae were considerably varied in accordance with the cell number of <i>T. suecica</i>, but there was no clear variation in the FLB community composition. This suggests that the PAB community may have a stronger association with the algal growth than the FLB community. Interestingly, irrespective of the growth phase, <i>Roseobacter</i> clade and genus <i>Muricauda</i> were predominant in both FLB and PAB communities, indicating that bacterial communities in <i>T. suecica</i> culture may positively affect the algae growth and that they are potentially capable of enhancing the <i>T. suecica</i> growth.