College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai, 201306, China.
College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai, 201306, China; International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), Shanghai Maritime University, Shanghai, 201306, China.
Mar Environ Res. 2023 Sep;190:106115. doi: 10.1016/j.marenvres.2023.106115. Epub 2023 Jul 25.
Ballast water is one of the main vectors for the spread of harmful organisms among geologically isolated waters. However, the successional processes of microbial functions and assembly processes in ballast water during the long-term shipping voyage remain unclear. In this study, the compositions, ecological functions, community assembly, and potential environmental drivers of bacteria and microeukaryotes were investigated in simulated ballast water microcosms for 120 days. The results showed that the diversity and compositions of the bacterial and microeukaryotic communities varied significantly in the initial 40 days (T0∼T40 samples) and then gradually converged. The relative abundance of Proteobacteria showed a distinct tendency to decrease (87.90%-41.44%), while that of Ascomycota exhibited an increasing trend (6.35%-62.12%). The functional groups also varied significantly over time and could be related to the variations of the microbial community. The chemoheterotrophy and aerobic chemoheterotrophy functional groups for bacteria decreased from 44.80% to 28.02% and from 43.77% to 25.39%, respectively. Additionally, co-occurrence network analysis showed that the structures of the bacterial community in T60∼T120 samples were more stable than those in T0∼T40 samples. Stochastic processes also significantly affected the community assembly of bacteria and microeukaryotes. pH played the most significant role in driving the structures and assembly processes of the bacterial and microeukaryotic communities. The results of this study could aid in the understanding of variations in the functions and ecological processes of bacterial and microeukaryotic communities in ballast water over time and provide a theoretical basis for its management.
压载水是有害生物在地理上隔离的水域中传播的主要载体之一。然而，在长期的航运过程中，压载水中微生物功能的演替过程和组装过程仍不清楚。在这项研究中，我们调查了模拟压载水中微生物群落在 120 天内的组成、生态功能、群落组装和潜在的环境驱动因素。结果表明，细菌和微真核生物群落的多样性和组成在初始 40 天（T0∼T40 样本）内变化显著，然后逐渐趋同。变形菌门的相对丰度表现出明显的下降趋势（87.90%-41.44%），而子囊菌门的相对丰度呈上升趋势（6.35%-62.12%）。功能组也随时间显著变化，与微生物群落的变化有关。细菌的化能异养和需氧化能异养功能组分别从 44.80%下降到 28.02%和从 43.77%下降到 25.39%。此外，共现网络分析表明，T60∼T120 样本中细菌群落的结构比 T0∼T40 样本更稳定。随机过程也显著影响了细菌和微真核生物群落的组装。pH 值对驱动细菌和微真核生物群落的结构和组装过程起着最重要的作用。本研究的结果可以帮助理解压载水中细菌和微真核生物群落功能和生态过程随时间的变化，并为其管理提供理论依据。
