Subminimal inhibitory concentration (sub-MIC) of antibiotic induces electroactive biofilm formation in bioelectrochemical systems
Subminimal inhibitory concentration (sub-MIC) of antibiotic induces electroactive biofilm formation in bioelectrochemical systems
复制标题
抗生素的次最小抑菌浓度 (sub-MIC) 可诱导生物电化学系统中电活性生物膜的形成
DOI：
10.1016/j.watres.2017.08.059
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发表时间：
2017
期刊：
影响因子：
12.8
通讯作者：
Wang Xin
中科院分区：
文献类型：
--
作者：
Zhou Lean;Li Tian;An Jingkun;Liao Chengmei;Li Nan;Wang Xin
电活性生物膜（EABs）由于其独特的直接胞外电子传递能力和在水污染控制中的潜在应用而备受关注。在这项研究中，我们首次确定了一种可用于EAB调节（抑制和促进）的化学物质。我们证实，妥布霉素，一种抗生素，以前证明抑制活性的EAB，是一种激动剂的EAB形成亚最小抑制浓度（亚MIC）。与对照组相比，妥布霉素浓度为0.05（1/80 MIC）和0.1 mg/L（1/40 MIC）时，达到3 A/m2所需的时间缩短，极限电流密度提高了17%。EAB活性的增强主要归因于生物量密度从289 ± 21 μg蛋白/cm 2增加到434 ± 12 μg蛋白/cm 2，生物膜厚度从28 ± 1 μ m增加到37 ± 0.5 μm。土壤微生物群落中的微生物种类选择性地从76%增加到82%，其丰度估计增加了1.63倍。使用模型菌株G. sulfreducensPCA进一步证实了加速生长。转录组学分析显示，0.05 mg/L的妥布霉素导致细胞色素和IV型菌毛相关基因的显著上调，这表明所观察到的电流增强的可能机制。这些发现扩展了我们对抗生素对EAB形成的调控以及混合培养中Geobacteria选择性富集的认识，对痕量抗生素对水环境中异化金属还原过程的潜在影响具有更广泛的意义。
Electroactive biofilms (EABs) generated from mixed inocula are attractive due to their unique direct extracellular electron transfer abilities and potential use in water pollution control. In this study, for the first time, we identified a chemical that can be used for EAB regulation (both inhibition and promotion). We confirmed that tobramycin, an antibiotic previously demonstrated to inhibit the activity of EABs, is an agonist of EAB formation at subminimal inhibitory concentrations (sub-MICs). Compared to the control, at tobramycin concentrations of 0.05 (1/80 MIC) and 0.1 mg/L (1/40 MIC), the time required to reach 3 A/m2was shorter, and the limiting current densities increased by 17%. The enhanced EAB activity was primarily attributed to the 50% increase in biomass density from 289 ± 21 to 434 ± 12 μg protein/cm2and the increased biofilm thickness from 28 ± 1 to 37 ± 0.5 μm. Geobacter species in the microbial communities were selectively increased from 76% to 82%, and their abundance was estimated to increase by 1.63-fold. The accelerated growth was further confirmed using the model strainG. sulfurreducensPCA. Transcriptomic analysis revealed that 0.05 mg/L of tobramycin led to a significant upregulation of genes related to cytochromes and the type IV pilus, suggesting a possible mechanism for the observed current enhancement. These findings extend our knowledge of the regulation of EAB formation by antibiotics and the selective enrichment ofGeobacterfrom a mixed culture, with broader implications on the potential impact of trace antibiotics on the dissimilatory metal reduction process in water environment.