This first-attempt study deciphered combined characteristics of species evolution and bioelectricity generation of microbial community in microbial fuel cells (MFCs) supplemented with Camellia green tea (GT) extracts for biomass energy extraction. Prior studies indicated that polyphenols-rich extracts as effective redox mediators (RMs) could exhibit significant electrochemical activities to enhance power generation in MFCs. However, the supplementation of Camellia GT extract obtained at room temperature with significant redox capabilities into MFCs unexpectedly exhibited obvious inhibitory effect towards power generation. This systematic study indicated that the presence of antimicrobial components (especially catechins) in GT extract might significantly alter the distribution of microbial community, in particular a decrease of microbial diversity and evenness. For practical applications to different microbial systems, pre-screening criteria of selecting biocompatible RMs should not only consider their promising redox capabilities (abiotic), but also possible inhibitory potency (biotic) to receptor microbes. Although Camellia tea extract was well-characterized as GRAS energy drink, some contents (e.g., catechins) may still express inhibition towards organisms and further assessment upon biotoxicity may be inevitably required for practice.

这项首次尝试的研究破译了微生物燃料电池（MFC）中微生物群落的物种进化和生物电产生的综合特征，并补充了山茶绿茶（GT）提取物以提取生物质能源。先前的研究表明，富含多酚的提取物作为有效的氧化还原介体（RM）可以表现出显着的电化学活性，以增强 MFC 的发电量。然而，将室温下获得的具有显着氧化还原能力的山茶GT提取物添加到MFC中却出乎意料地表现出明显的发电抑制作用。这项系统研究表明，GT 提取物中抗菌成分（尤其是儿茶素）的存在可能会显着改变微生物群落的分布，特别是微生物多样性和均匀度的降低。对于不同微生物系统的实际应用，选择生物相容性RM的预筛选标准不仅应考虑其有前景的氧化还原能力（非生物），还应考虑对受体微生物可能的抑制效力（生物）。尽管山茶花提取物被认为是GRAS能量饮料，但某些成分（例如儿茶素）仍可能对生物体表现出抑制作用，实践中不可避免地需要进一步评估生物毒性。