Electrochemically Active Biofilms as an Indicator of Soil Health
Electrochemically Active Biofilms as an Indicator of Soil Health
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DOI：
10.1149/1945-7111/ac1e56
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发表时间：
2021-08
影响因子：
3.9
通讯作者：
A. Mohamed;E. Sanchez;Natalie Sanchez;M. Friesen;H. Beyenal
中科院分区：
文献类型：
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作者：
A. Mohamed;E. Sanchez;Natalie Sanchez;M. Friesen;H. Beyenal
土壤健康是一种复杂的现象，反映了土壤支持植物生长和其他生态系统功能的能力。据我们所知，在土壤环境中的细胞外电子传递过程的研究是有限的，可以提供新的知识和监测土壤健康的新方法。土壤中的电化学活动可以通过插入惰性电极来研究。一旦电极被极化到有利的电位，附近的微生物就会附着在电极上并生长为生物膜。生物膜是土壤的主要组成部分，在微生物活动和群落动态中起着关键作用。我们的工作旨在研究健康和不健康土壤的电化学行为，使用计时电流法和循环伏安法。我们开发了一种生物电化学土壤反应器，用于使用从库克农学农场长期农业生态研究站点获取的健康和不健康土壤进行电化学测量;土壤显示出相似的物理和化学特性，但健康土壤的植物生长更高。在土壤反应器中安装碳布电极，我们探讨了这两种土壤的电化学信号。首先，我们测量了氧化还原变化的深度，发现还原条件普遍存在于健康的土壤。目前的测量结果表明，健康和不健康的土壤之间有明显的差异。扫描电子显微镜图像显示，微生物附着在健康土壤的电极的存在下，但不健康的土壤。葡萄糖的加入刺激了两种土壤类型的电流，并导致两种土壤类型之间的循环伏安图的差异收敛。我们的工作表明，我们可以使用电流作为微生物代谢活动的代表，以区分健康和不健康的土壤。
Soil health is a complex phenomenon that reflects the ability of soil to support both plant growth and other ecosystem functions. To our knowledge, research on extracellular electron transfer processes in soil environments is limited and could provide novel knowledge and new ways of monitoring soil health. Electrochemical activities in the soil can be studied by inserting inert electrodes. Once the electrode is polarized to a favorable potential, nearby microorganisms attach to the electrodes and grow as biofilms. Biofilms are a major part of the soil and play critical roles in microbial activity and community dynamics. Our work aims to investigate the electrochemical behavior of healthy and unhealthy soils using chronoamperometry and cyclic voltammetry. We developed a bioelectrochemical soil reactor for electrochemical measurements using healthy and unhealthy soils taken from the Cook Agronomy Farm Long-Term Agroecological Research site; the soils showed similar physical and chemical characteristics, but there was higher plant growth where the healthy soil was taken. Using carbon cloth electrodes installed in these soil reactors, we explored the electrochemical signals in these two soils. First, we measured redox variations by depth and found that reducing conditions were prevalent in healthy soils. Current measurements showed distinct differences between healthy and unhealthy soils. Scanning electron microscopy images showed the presence of microbes attached to the electrode for healthy soil but not for unhealthy soil. Glucose addition stimulated current in both soil types and caused differences in cyclic voltammograms between the two soil types to converge. Our work demonstrates that we can use current as a proxy for microbial metabolic activity to distinguish healthy and unhealthy soil.