Contrasting controls on seasonal and spatial distribution of marine cable bacteria ( Candidatus Electrothrix ) and Beggiatoaceae in seasonally hypoxic Chesapeake Bay
Contrasting controls on seasonal and spatial distribution of marine cable bacteria ( Candidatus Electrothrix ) and Beggiatoaceae in seasonally hypoxic Chesapeake Bay
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季节性缺氧切萨皮克湾海洋电缆细菌（Candidatus Electrothrix）和 Beggiatoaceae 季节和空间分布的对比控制
DOI：
10.1002/lno.12087
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发表时间：
2022
影响因子：
4.5
通讯作者：
Song, Bongkeun
中科院分区：
文献类型：
--
作者：
Malkin, Sairah Y.;Liau, Pinky;Kim, Carol;Hantsoo, Kalev G.;Gomes, Maya L.;Song, Bongkeun
海洋电缆细菌（Candidatus Electrothrix）和大型无色硫氧化细菌（例如 Beggiatoaceae）是沿海环境中广泛存在的硫营养菌，但可能对生物地球化学循环产生不同的影响。然而，人们对影响其利基划分的因素仍然知之甚少。为了绘制它们的分布图并评估它们在自然环境中的生长限制，我们使用显微镜结合 16S rRNA 基因扩增子测序和生物地球化学表征，检查了切萨皮克湾两个地点的不同季节的表面沉积物，并对比了季节性氧气消耗水平。我们发现，以与Candidatus Electrothrixcommunis密切相关的单一系统型为主的电缆细菌在冬季和春季在经历夏季缺氧的中央河道部位繁盛。在这里，电缆细菌密度与表面沉积物叶绿素（植物碎屑沉积的代表）呈正相关。在支持大型生物扰动的邻近浅滩处，电缆细菌也以较低的面密度存在。 Beggiatoaceae 在该地点更为丰富，其生物量与沉积物呼吸呈正相关，但另外还可能受到硫化物积累的抑制，这一点在一个夏天就很明显。春季植物碎屑沉积事件与 Beggiatoaceae 和多种 Candidatus Electrothrixphylotypes 的增殖有关，电缆细菌长度达到 1000 米 cm−2。这些观察结果表明，春季开花对推动神秘硫循环的热点时刻具有潜在影响。我们的结果表明，底栖硫营养生物种群之间存在复杂的相互作用，生物扰动和底水溶解氧、沉积物硫化物和有机物流入的季节性振荡是其分布的重要驱动因素。
Marine cable bacteria (Candidatus Electrothrix) and large colorless sulfur‐oxidizing bacteria (e.g., Beggiatoaceae) are widespread thiotrophs in coastal environments but may exert different influences on biogeochemical cycling. Yet, the factors governing their niche partitioning remain poorly understood. To map their distribution and evaluate their growth constraints in a natural setting, we examined surface sediments across seasons at two sites with contrasting levels of seasonal oxygen depletion in Chesapeake Bay using microscopy coupled with 16S rRNA gene amplicon sequencing and biogeochemical characterization. We found that cable bacteria, dominated by a single phylotype closely affiliated toCandidatus Electrothrixcommunis, flourished during winter and spring at a central channel site which experiences summer anoxia. Here, cable bacteria density was positively correlated with surface sediment chlorophyll, a proxy of phytodetritus sedimentation. Cable bacteria were also present with a lower areal density at an adjacent shoal site which supports bioturbating macrofauna. Beggiatoaceae were more abundant at this site, where their biomass was positively correlated with sediment respiration, but additionally potentially inhibited by sulfide accumulation which was evident during one summer. A springtime phytodetritus sedimentation event was associated with a proliferation of Beggiatoaceae and multipleCandidatus Electrothrixphylotypes, with cable bacteria reaching 1000 m length cm−2. These observations indicate the potential impact of a spring bloom in driving a hot moment of cryptic sulfur cycling. Our results suggest complex interactions between benthic thiotroph populations, with bioturbation and seasonal oscillations in bottom water dissolved oxygen, sediment sulfide, and organic matter influx as important drivers of their distribution.