The Porter School of Environmental Studies, Tel Aviv University, Tel Aviv, Israel.
The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.
mBio. 2021 Mar 2;12(2):e03629-20. doi: 10.1128/mBio.03629-20.
Microbial fuel cells (MFCs) generate energy while aiding the biodegradation of waste through the activity of an electroactive mixed biofilm. Metabolic cooperation is essential for MFCs' efficiency, especially during early colonization. Thus, examining specific ecological processes that drive the assembly of anode biofilms is highly important for shortening startup times and improving MFC performance, making this technology cost-effective and sustainable. Here, we use metagenomics to show that bioaugmentation of the anode surface with a taxonomically defined electroactive consortium, dominated by , resulted in an extremely rapid current density generation. Conversely, the untreated anode surface resulted in a highly stochastic and slower biofilm assembly. Remarkably, an efficient anode colonization process was obtained only if wastewater was added, leading to a nearly complete replacement of the bioaugmented community by Although different approaches to improve MFC startup have been investigated, we propose that only the combination of anode bioaugmentation with wastewater inoculation can reduce stochasticity. Such an approach provides the conditions that support the growth of specific newly arriving species that positively support the fast establishment of a highly functional anode biofilm. Mixed microbial communities play important roles in treating wastewater, in producing renewable energy, and in the bioremediation of pollutants in contaminated environments. While these processes are well known, especially the community structure and biodiversity, how to efficiently and robustly manage microbial community assembly remains unknown. Moreover, it has been shown that a high degree of temporal variation in microbial community composition and structure often occurs even under identical environmental conditions. This heterogeneity is directly related to stochastic processes involved in microbial community organization, similarly during the initial stages of biofilm formation on surfaces. In this study, we show that anode surface pretreatment alone is not sufficient for a substantial improvement in startup times in microbial fuel cells (MFCs), as previously thought. Rather, we have discovered that the combination of applying a well-known consortium directly on the anode surface together with wastewater (including the bacteria that they contain) is the optimized management scheme. This allowed a selected colonization process by the wastewater species, which improved the functionality relative to that of untreated systems.
微生物燃料电池 (MFC) 通过电活性混合生物膜的活性来产生能量并辅助废物的生物降解。代谢合作对于 MFC 的效率至关重要，特别是在早期定植阶段。因此，研究驱动阳极生物膜组装的特定生态过程对于缩短启动时间和提高 MFC 性能非常重要，从而使该技术具有成本效益和可持续性。在这里，我们使用宏基因组学表明，通过电活性群落（主要由 主导）对阳极表面进行生物增强，可极大地促进电流密度的快速产生。相反，未经处理的阳极表面导致生物膜组装高度随机且速度较慢。值得注意的是，只有添加废水才能获得有效的阳极定植过程，导致经过生物增强的群落几乎完全被 取代。虽然已经研究了许多改善 MFC 启动的方法，但我们提出，只有将阳极生物增强与废水接种相结合，才能减少随机性。这种方法提供了支持特定新到达物种生长的条件，这些物种可以积极支持快速建立高度功能性的阳极生物膜。混合微生物群落在处理废水、生产可再生能源和在受污染环境中生物修复污染物方面发挥着重要作用。虽然这些过程是众所周知的，特别是群落结构和生物多样性，但如何有效地和稳健地管理微生物群落组装仍然未知。此外，已经表明，即使在相同的环境条件下，微生物群落组成和结构的时间变化也很大。这种异质性与微生物群落组织中涉及的随机过程直接相关，同样在表面生物膜形成的初始阶段也是如此。在这项研究中，我们表明，如前所述，单独对阳极表面进行预处理不足以大大缩短微生物燃料电池 (MFC) 的启动时间。相反，我们发现，将已知的群落直接应用于阳极表面与废水（包括其中的细菌）相结合的组合是优化的管理方案。这允许废水物种进行有选择的定植过程，从而提高了相对于未处理系统的功能。
