Lake Sediment Methane Responses to Organic Matter are Related to Microbial Community Composition in Experimental Microcosms
Lake Sediment Methane Responses to Organic Matter are Related to Microbial Community Composition in Experimental Microcosms
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DOI：
10.3389/fenvs.2022.834829
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发表时间：
2022-03
期刊：
影响因子：
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通讯作者：
B. Bertolet;C. Koepfli;Stuart E. Jones
中科院分区：
文献类型：
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作者：
B. Bertolet;C. Koepfli;Stuart E. Jones
湖泊沉积物微生物群落介导碳成岩作用。然而，不同湖泊的微生物群落组成是不同的，群落组成的变化如何影响沉积物对环境变化的响应仍然不确定。沉积物甲烷（CH4）产量因湖泊初级生产力和有机质供应的增加而显著提高。然而，不同湖泊对CH4产生的响应程度不同，最近的研究表明微生物群落在调节这一响应中发挥了作用。在此，我们对22个湖泊进行了沉积物培养实验，以确定沉积物微生物群落组成的变化是否与沉积物CH4产量对有机质增加的响应有关。为了研究具有不同沉积物微生物群落的湖泊，我们对22个湖泊进行了pH梯度采样。我们在培养皿中添加了干藻生物量，结果表明CH4产量对有机质供应变化的响应变化与沉积物微生物群落组成指标显著相关。具体而言，非产甲烷菌群落的多样性和丰富度最能预测沉积物CH4对有机质添加的响应。此外，微生物丰度和先前存在的有机质有效性指标都不能解释反应中有意义的变化。因此，我们的研究结果为沉积物微生物群落的差异影响CH4生产对有机质有效性变化的响应提供了实验支持。
Lake sediment microbial communities mediate carbon diagenesis. However, microbial community composition is variable across lakes, and it is still uncertain how variation in community composition influences sediment responses to environmental change. Sediment methane (CH4) production has been shown to be substantially elevated by increased lake primary productivity and organic matter supply. However, the magnitude of the response of CH4 production varies across lakes, and recent studies suggest a role for the microbial community in mediating this response. Here, we conducted sediment incubation experiments across 22 lakes to determine whether variation in sediment microbial community composition is related to the response of sediment CH4 production to increases in organic matter. We sampled the 22 lakes across a gradient of pH in order to investigate lakes with variable sediment microbial communities. We manipulated the incubations with additions of dried algal biomass and show that variation in the response of CH4 production to changes in organic matter supply is significantly correlated with metrics of sediment microbial community composition. Specifically, the diversity and richness of the non-methanogen community was most predictive of sediment CH4 responses to organic matter additions. Additionally, neither metrics of microbial abundance nor preexisting organic matter availability explained meaningful variation in the response. Thus, our results provide experimental support that differences in sediment microbial communities influences CH4 production responses to changes in organic matter availability.