College of Marine Science and Engineering, Nanjing Normal University, Nanjing 210023, China; Coastal Zone Resources and Environment Engineering Research Center of Jiangsu Province, Nanjing 210023, China.
Jiangsu Yunfan Testing Technology Co., Ltd., Nanjing 210033, China.
J Hazard Mater. 2023 Oct 15;460:132309. doi: 10.1016/j.jhazmat.2023.132309. Epub 2023 Aug 15.
The microbial community assembly processes and underlying mechanisms in response to heavy metal accumulation in coastal sediments remain underexplored. In this study, the heavy metal concentration in samples were found below the marine sediment quality standards. Through partial Mantel tests and linear regression analysis, Cd was identified as the major influencing factor, displaying strongest correlation with the bacterial community in the sediments. The class Desulfuromonadia was identified as a biomarker which showed enrichment in the sediments with high Cd content. Additionally, the results of null model and the neutral community model demonstrated the prominent role of stochastic processes in the assembly of bacterial community. However, with the increase in Cd concentration, the influence of selection processes intensified, resulting in a decline in species migration rate and subsequent reduction in ecological niche width. Furthermore, the intensified competition and an increase in keystone species among bacterial populations further enhanced the stability of the microbial co-occurrence network in response to high Cd concentration. This study offers an insight into the effects of heavy metal on microbial assembly and coexistence, which are conducive to marine ecosystem management and conservation.
在沿海沉积物中，微生物群落组装过程和潜在机制对重金属积累的响应仍未得到充分探索。在本研究中，发现样品中的重金属浓度低于海洋沉积物质量标准。通过部分 Mantel 测试和线性回归分析，确定 Cd 是主要影响因素，与沉积物中的细菌群落相关性最强。脱硫单胞菌属被鉴定为一个生物标志物，在 Cd 含量高的沉积物中表现出富集。此外，零模型和中性群落模型的结果表明，随机过程在细菌群落的组装中起着突出的作用。然而，随着 Cd 浓度的增加，选择过程的影响加剧，导致物种迁移率下降，生态位宽度随之减小。此外，细菌种群之间竞争的加剧和关键种的增加进一步增强了微生物共生网络对高 Cd 浓度的稳定性。本研究深入了解了重金属对微生物组装和共存的影响，有助于海洋生态系统的管理和保护。
