College of Resources Environment and Tourism, Capital Normal University, Beijing, China.
College of Resources Environment and Tourism, Capital Normal University, Beijing, China.
Chemosphere. 2022 Dec;309(Pt 1):136659. doi: 10.1016/j.chemosphere.2022.136659. Epub 2022 Oct 3.
Bacteria within a metacommunity could be partitioned into different subcommunities ecological assemblages in light of potential importance for the community function. It is unknown how abundant and rare microbial subcommunities in urban river sediments respond to heavy metal pollutants. Using high-throughput sequencing, we analyzed these response patterns in the heavliy polluted (Beijing, China). We found that this river faces substantial ecological risks, owing to high rates of Cd and Hg pollution from urban activities. Surprisingly, abundant and rare subcommunity structures showed opposite responses to heavy metals. Abundant taxa, such as Crenarchaeota and Euryarchaeota, are resistant to heavy metal pollution through the synergistic of ammonia nitrogen (NH-N) and total phosphorus (TP). By contrast, rare taxa, such as Verrucomicrobia, Fibrobacteres, Berkelbacteria, and Euryarchaeota, had a high synergy with NH-N and TP with high a resilience to heavy metal pollution. However, the functions of both abundant and rare subcommunities showed a similar response to heavy metal pollutants, especially in denitrification processes. The abundant taxa responded to heavy metal pollution through methanogenesis by CO reduction with H, human pathogens nosocomia, sulfate respiration, photoheterotrophy, and dark sulfide oxidation synergy with NH-N and TP. The rare taxa responded to heavy metals through methanogenesis by CO reduction with H, cellulolysis, sulfate respiration, intracellular parasites, nitrate reduction and plant pathogen. We observed distinct patterns between the structural and functional responses of microbial subcommunities to heavy metal pollutants. Our findings support the concept that denitrification processes are sensitive to but not inhibited by high levels of heavy metals pollution. We propose that the structures and functions of the abundant and rare microbial subcommunities could inform the management of pollutants in heavily polluted urban river ecosystems at fine geographical scales.
在宏群落中，细菌可以根据对群落功能的潜在重要性被分为不同的亚群落生态组合。目前尚不清楚城市河底沉积物中的丰富和稀有微生物亚群落对重金属污染物有何响应。本研究采用高通量测序技术，分析了中国北京重度污染河流中的这些响应模式。研究发现，由于城市活动导致 Cd 和 Hg 污染率高，该河流面临着巨大的生态风险。令人惊讶的是，丰富和稀有亚群落结构对重金属表现出相反的响应。丰度较高的类群，如古菌门和广古菌门，通过氨氮（NH-N）和总磷（TP）的协同作用，对重金属污染具有抵抗力。相比之下，稀有类群，如疣微菌门、纤维杆菌门、伯克霍尔德氏菌门和广古菌门，与 NH-N 和 TP 具有很高的协同作用，对重金属污染具有很强的恢复能力。然而，丰富和稀有亚群落的功能对重金属污染物表现出相似的响应，特别是在反硝化过程中。丰度较高的类群通过 CO 还原与 H 生成甲烷、医院病原体共生、硫酸盐呼吸、光异养、以及 NH-N 和 TP 与甲烷生成协同作用来响应重金属污染。稀有类群通过 CO 还原与 H 生成甲烷、纤维素分解、硫酸盐呼吸、细胞内寄生虫、硝酸盐还原和植物病原体来响应重金属。我们观察到微生物亚群落的结构和功能对重金属污染物的响应存在明显差异。我们的研究结果支持这样一种观点，即反硝化过程对重金属污染水平敏感，但不受其抑制。我们提出，丰富和稀有微生物亚群落的结构和功能可以为重金属污染严重的城市河流生态系统在精细地理尺度上的管理提供信息。
