Response of bacterial communities (Marivita, Marinobacter, and Oceanicaulis) in the phycosphere to the growth of Phaeodactylum tricornutum in different inorganic nitrogen sources

Introduction In marine ecosystems, microbial communities are important drivers of material circulation and energy flow. The complex interactions between phytoplankton bacterial constitute one the most crucial ecological relationships in environment. Inorganic nitrogen can affect type relationship algae bacteria. However, quantitative communities, inorganic nitrogen, remains unclear. Methods Under laboratory conditions, we altered forms (nitrate ammonium) amounts sources to study dynamics biomass, diversity, community structure phycosphere model species Phaeodactylum tricornutum . during P. growth was analyzed using Illumina HiSeq sequencing 16S rDNA amplicons. Results results indicated that concentration main factor promoting biomass growth. change algal would significantly increase biomass. algal-bacteria co-culture system 1.5 ~ 5 times conditional control groups without microalgae under same culture conditions. variation also affected phycosphere. When exponential phase (96 192 h), differed high- low-concentration groups. difference over time high-concentration more prominent than (HA HN), relative abundance Marivita Marinobacter , engaged transformation aquatic gradually decreased with time. Oceanicaulis closely related growth, increased Discussion above phenomena might be Our explain when how responded variations. provides a foundation for among nutrients, microalgae, bacteria this system.