Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan; Department of Natural Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan.
Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan.
Sci Total Environ. 2024 Jun 20;930:172798. doi: 10.1016/j.scitotenv.2024.172798. Epub 2024 Apr 28.
Seagrass meadows produce organic carbon and deposit it on the seabed through the decaying process. Microbial activity is closely related to the process of eelgrass death and collapse. We investigated the microbial community structure of eelgrass during the eelgrass decomposition process by using a microcosm containing raw seawater and excised eelgrass leaves collected from a Zostera marina bed in Futtsu, Chiba Prefecture, Japan. The fast-growing microbes (i.e., Alphaproteobacteria, Gammaproteobacteria, and Flavobacteriia) rapidly adhered to the eelgrass leaf surface and proliferated in the first two weeks but gradually decreased the relative abundance as the months moved on. On the other hand, the slow-growing microbes (i.e., Cytophagia, Anaerolineae, Thaumarchaeota, and Actinobacteria) became predominant over the eelgrass surface late in the culture experiment (120, 180 days). The fast-growing groups of Gammaproteobacteria and Flavobacteriia appear to be closely related to the initial decomposition of eelgrass, especially the rapid decomposition of leaf-derived biopolymers. Changes in nitrogen content due to the bacterial rapid consumption of readily degradable organic carbon induced changes in the community structure at the early stage of eelgrass decomposition. In addition, shifts in the C/N ratio were driven by microbial community changes during later decomposition phases.
海草床通过腐烂过程产生有机碳并将其沉积在海底。微生物活动与鳗草死亡和崩溃的过程密切相关。我们通过使用包含原始海水和从日本千叶县房总采集的鳗草叶片的微宇宙来研究鳗草分解过程中的微生物群落结构。快速生长的微生物（即α变形菌、γ变形菌和黄杆菌）迅速附着在鳗草叶片表面，并在前两周内增殖，但随着时间的推移，相对丰度逐渐降低。另一方面，慢速生长的微生物（即噬细胞菌、厌氧杆菌、古菌和放线菌）在培养实验后期（120、180 天）在鳗草表面占优势。快速生长的γ变形菌和黄杆菌群体似乎与鳗草的初始分解密切相关，尤其是叶片衍生生物聚合物的快速分解。由于细菌快速消耗易降解的有机碳，导致氮含量的变化，从而在鳗草分解的早期阶段引起群落结构的变化。此外，在后期分解阶段，微生物群落的变化驱动了 C/N 比的变化。
