Volatile and Dissolved Organic Carbon Sources Have Distinct Effects on Microbial Activity, Nitrogen Content, and Bacterial Communities in Soil
Volatile and Dissolved Organic Carbon Sources Have Distinct Effects on Microbial Activity, Nitrogen Content, and Bacterial Communities in Soil
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DOI：
10.1007/s00248-022-01967-0
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发表时间：
2021-11
影响因子：
3.6
通讯作者：
Steven G. McBride;Ernest D. Osburn;Jane L Lucas;Julia S. Simpson;Taylor Brown;J. Barrett;M. Strickland
中科院分区：
文献类型：
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作者：
Steven G. McBride;Ernest D. Osburn;Jane L Lucas;Julia S. Simpson;Taylor Brown;J. Barrett;M. Strickland
微生物利用土壤碳化合物的变化是土壤地球化学过程和微生物群落组成的主要驱动力。土壤有效碳基质包括低分子量溶解性有机碳（LMW-DOC）和挥发性有机化合物（VOCs）。为了比较不同水分条件下LMW-DOC和VOCs对土壤化学和微生物群落的影响，我们进行了5个土壤含水量水平（25 - 70%持水量）和5个碳添加水平的微观实验：无碳对照、2种溶解性化合物（葡萄糖和草酸）和2种挥发性化合物（甲醇和α-蒎烯）。在整个土壤呼吸的微生物活性进行了测量，在实验结束时，我们测量了可提取的土壤有机碳和总可提取的氮，并采用扩增子测序的原核生物群落的特点。所有的C修正案增加微生物活性，和所有除草酸盐减少总提取氮。同样地，个别门对特定的条件作出反应，例如，变形菌增加下添加葡萄糖，和两种挥发性有机化合物。此外，我们观察到水分和C修正案之间的相互作用，其中两种VOC处理具有较高的微生物活性比LMW-DOC处理和控制在低水分。在整个水分和C处理，我们确定，Chloroflexi，Nitrosspiritum，变形菌，和Verrucomicrobia是强有力的预测微生物活性，而放线菌，拟杆菌，和Thaumarcheota强烈预测土壤中可提取的氮。这些结果表明，土壤原核生物的不稳定C源的类型可以影响微生物多样性和生态系统功能，挥发性有机化合物可能会驱动微生物的功能和组成在低水分条件下。
Variation in microbial use of soil carbon compounds is a major driver of biogeochemical processes and microbial community composition. Available carbon substrates in soil include both low molecular weight-dissolved organic carbon (LMW-DOC) and volatile organic compounds (VOCs). To compare the effects of LMW-DOC and VOCs on soil chemistry and microbial communities under different moisture regimes, we performed a microcosm experiment with five levels of soil water content (ranging from 25 to 70% water-holding capacity) and five levels of carbon amendment: a no carbon control, two dissolved compounds (glucose and oxalate), and two volatile compounds (methanol and α-pinene). Microbial activity was measured throughout as soil respiration; at the end of the experiment, we measured extractable soil organic carbon and total extractable nitrogen and characterized prokaryotic communities using amplicon sequencing. All C amendments increased microbial activity, and all except oxalate decreased total extractable nitrogen. Likewise, individual phyla responded to specific C amendments—e.g., Proteobacteria increased under addition of glucose, and both VOCs. Further, we observed an interaction between moisture and C amendment, where both VOC treatments had higher microbial activity than LMW-DOC treatments and controls at low moisture. Across moisture and C treatments, we identified that Chloroflexi, Nitrospirae, Proteobacteria, and Verrucomicrobia were strong predictors of microbial activity, while Actinobacteria, Bacteroidetes, and Thaumarcheota strongly predicted soil extractable nitrogen. These results indicate that the type of labile C source available to soil prokaryotes can influence both microbial diversity and ecosystem function and that VOCs may drive microbial functions and composition under low moisture conditions.