Nutrient (C, N and P) enrichment induces significant changes in the soil metabolite profile and microbial carbon partitioning
Nutrient (C, N and P) enrichment induces significant changes in the soil metabolite profile and microbial carbon partitioning
复制标题
DOI：
10.1016/j.soilbio.2022.108779
复制
发表时间：
2022-07-20
影响因子：
9.7
通讯作者：
Jones, Davey L.
中科院分区：
文献类型：
--
作者：
Brown, Robert W.;Chadwick, David R.;Jones, Davey L.
土壤有机质（SOM）和碳（C）在土壤中的循环是由关键常量营养素，特别是氮（N）和磷（P）的存在所决定的。这些养分的相对比例对土壤中微生物生长和养分处理的潜在速率有直接影响，因此对生态系统功能至关重要。然而，改变土壤养分化学计量对有机小分子（即，代谢物）组成和微生物群落的循环仍然知之甚少。在这里，我们的目的是解开化学计量平衡的养分添加对土壤代谢谱和表观微生物碳利用效率（CUE）的影响，通过添加不稳定的C源（葡萄糖）结合N和/或P.加入葡萄糖后，加入到微生物生物量（48小时），代谢产物分析进行超高效液相色谱-串联质谱（UPLC-MS/MS）。在所有处理中鉴定出494种代谢物，主要由脂质（n = 199）、氨基酸（n = 118）和碳水化合物（n = 43）组成，其中>97%的代谢物在至少一次处理之间浓度出现显着变化。总体而言，葡萄糖-C除了一般增加土壤中其他碳水化合物的合成，而除了C和N一起增加肽的合成，指示蛋白质的形成和营业额。C和P的组合显着增加了脂肪酸合成的数量。有PLFA衍生的微生物群落结构或微生物生物量的C，N和P添加后没有显着的变化。此外，N添加导致葡萄糖-C分配到合成代谢过程中的增加（即，增加CUE），表明微生物群落是N限制的，而不是P限制的。基于这里观察到的代谢谱，我们得出结论，无机营养富集导致微生物群落内的初级和次级代谢发生重大变化，导致资源流的变化，从而改变土壤功能，然而，微生物群落表现出显着的代谢灵活性。
The cycling of soil organic matter (SOM) and carbon (C) within the soil is governed by the presence of key macronutrients, particularly nitrogen (N) and phosphorus (P). The relative ratio of these nutrients has a direct effect on the potential rates of microbial growth and nutrient processing in soil and thus is fundamental to ecosystem functioning. However, the effect of changing soil nutrient stoichiometry on the small organic molecule (i.e., metabolite) composition and cycling by the microbial community remains poorly understood. Here, we aimed to disentangle the effect of stoichiometrically balanced nutrient addition on the soil metabolomic profile and apparent microbial carbon use efficiency (CUE) by adding a labile C source (glucose) in combination with N and/or P. After incorporation of the added glucose into the microbial biomass (48 h), metabolite profiling was undertaken by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). 494 metabolites were identified across all treatments mainly consisting of lipids (n = 199), amino acids (n = 118) and carbohydrates (n = 43), >97% of which showed significant changes in concentration between at least one treatment. Overall, glucose-C addition generally increased the synthesis of other carbohydrates in soil, while addition of C and N together increased peptide synthesis, indicative of protein formation and turnover. The combination of C and P significantly increased the number of fatty acids synthesised. There was no significant change in the PLFA-derived microbial community structure or microbial biomass following C, N and P addition. Further, N addition led to an increase in glucose-C partitioning into anabolic processes (i.e., increased CUE), suggesting the microbial community was N, but not P limited. Based on the metabolomic profiles observed here, we conclude that inorganic nutrient enrichment causes substantial shifts in both primary and secondary metabolism within the microbial community, leading to changes in resource flow and thus soil functioning, however, the microbial community illustrated significant metabolic flexibility.