Volatile organic compounds (VOCs) allow sensitive differentiation of biological soil quality
Volatile organic compounds (VOCs) allow sensitive differentiation of biological soil quality
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DOI：
10.1016/j.soilbio.2021.108187
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发表时间：
2021-03-04
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.;Bull, Ian D.;Jones, Davey L.
了解不同土壤条件下生物群落功能的变化是有效监测土壤质量和缓解土壤退化的关键。目前的生物土壤质量测量方法存在缺陷，大多数技术费用高、通量低或只关注社区的某一组成部分。本研究的目的是评估挥发组学作为土壤微生物群落分析方法的用途，并将该技术与磷脂脂肪酸 (PLFA) 分析作为生物土壤质量的测量方法进行比较。农业草原土壤（Eutric Cambisol）在重复的实验室中环境中受到一系列压力。处理方法包括在存在或不存在植物残留物的情况下通过用淡水或盐水淹没来施加缺氧/缺氧。然后将每种处理的挥发性有机化合物 (VOC) 和 PLFA 特征与未修改的中生态系统进行比较。我们假设土壤的 VOC 指纹对微生物代谢状态/功能的变化高度敏感，从而为评估土壤生物健康提供 PLFA 的补充方法。我们还假设，在确定土壤处理之间的差异时，VOC 特征比 PLFA 具有更大的辨别力。采用顶空固相微萃取 (HSSPME) 方法结合气相色谱四极杆飞行时间质谱 (GC/Q-TOFMS) 来分析每种土壤产生的 VOC 的广谱。在所有土壤处理中，检测到 514 个独特的 VOC 峰值。总体而言，VOC 在分离土壤质量处理方面表现出比 PLFA 分析更高的灵敏度。确定了 18 种单独的 VOC，它们是造成这种分离的主要原因（例如吲哚、α-紫罗兰酮、异佛尔酮、3-辛酮、对甲酚、2-乙基苯酚）。用残留物改良的厌氧土壤显示出与其他处理的最大分离，这种差异大部分与十种单独的挥发性有机化合物有关。厌氧土壤还显示出挥发性有机化合物排放量显着减少，但挥发性有机化合物排放总量增加。总之，我们的研究结果提供了证据，表明土壤挥发性有机化合物对土壤质量的变化做出快速反应，因此作为生物土壤质量的新型功能相关诊断措施具有巨大的潜力。
Understanding the change in function of the biological community under different soil conditions is key to effective soil quality monitoring and mitigation of soil degradation. Current measures of biological soil quality suffer from drawbacks with most techniques having high expense, low throughput or a narrow focus on one component of the community. The aim of this study was to assess the use of volatilomics as a method to profile the soil microbial community and compare the technique to phospholipid fatty acid (PLFA) profiling as a measure of biological soil quality. An agricultural grassland soil (Eutric Cambisol) was subjected to a range of stresses in replicate laboratory mesocosms. Treatments included the imposition of hypoxia/anoxia by flooding with freshwater or saltwater in the presence or absence of plant residues. The volatile organic compound (VOC) and PLFA profile of each treatment was then compared to unamended mesocosms. We hypothesized that the VOC fingerprint of soil would be highly responsive to changes in microbial metabolic status/functioning and thus provide a complementary approach to PLFAs for evaluating soil biological health. We also hypothesized that the VOC profile would have greater discriminatory power than PLFAs for determining differences between soil treatments. A headspace solid phase microextraction (HSSPME) method coupled with gas chromatography quadrupole-time of flight mass spectrometry (GC/Q-TOFMS) was used to analyse the broad spectrum of VOCs produced by each soil. Across all soil treatments 514 unique VOC peaks were detected. Overall, VOCs showed greater sensitivity than the PLFA analysis in separating soil quality treatments. Eighteen individual VOCs were identified which were primarily responsible for this separation (e.g. indole, a-ionone, isophorone, 3-octanone, p-cresol, 2-ethyl-phenol). Anaerobic soils amended with residues showed the greatest separation from other treatments, with most of this differentiation associated with ten individual VOCs. The anaerobic soils also showed a significant reduction in the number of VOCs emitted but an increase in total VOC emissions. In conclusion, our findings provide evidence that soil VOCs rapidly respond to changes in soil quality and therefore hold great potential as a novel functionally relevant diagnostic measure of biological soil quality.