Unignorable toxicity of formaldehyde on electroactive bacteria in bioelectrochemical systems
Unignorable toxicity of formaldehyde on electroactive bacteria in bioelectrochemical systems
复制标题
甲醛对生物电化学系统中的电活性细菌具有不可忽视的毒性。
DOI：
10.1016/j.envres.2020.109143
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发表时间：
2020-04-01
影响因子：
8.3
通讯作者：
Li, Nan
中科院分区：
文献类型：
--
作者：
Li, Tian;Chen, Fan;Li, Nan
甲醛对生态系统构成严重威胁，在电活性生物膜(EAB)传感器中被广泛用作获得电信号反馈的毒性指示剂。虽然人们已经采取了许多优化措施来改善EAB对甲醛的性能，但几乎没有研究讨论甲醛对EAB的毒性。在这里，EABs以稳定的电流密度(8.9+/-0.2A/m(2))驯化，然后注入甲醛。注入1ppm和10ppm甲醛后，电流密度分别比对照组降低27%和98%。甲醛的生态毒性导致电流的不可逆损失，分别为3%(1ppm)和81%(10ppm)。激光共聚焦扫描显微镜和扫描电子显微镜结果表明，甲醛对氧化还原活性有抑制作用，死亡/破碎细胞数从2%增加到40%(1ppm)和91%(10ppm)。由于甲醛引起的裂解反应，总蛋白和胞外聚合物的含量分别下降了28%(1ppm)和75%(10ppm)以上。细菌群落分析表明，土杆菌的比例从81%下降到53%(1ppm)和24%(10ppm)。因此，当前的产量受到了显著的损害，不可逆转的损失增加了。毒理学分析表明，甲醛扰乱了细胞的生理指标，从而诱导细胞凋亡。这些发现填补了生物电化学系统中毒物对EAB的生态毒理学的空白。
Formaldehyde poses significant threats to the ecosystem and is widely used as a toxicity indicator to obtain electrical signal feedback in electroactive biofilm (EAB)-based sensors. Although many optimizations have been adopted to improve the performance of EAB to formaldehyde, nearly no studies have discussed the toxicity of formaldehyde to EAB. Here, EABs were acclimated with a stable current density (8.9 +/- 0.2 A/m(2)) and then injected with formaldehyde. The current density decreased by 27% and 98% after the injection of 1 and 10 ppm formaldehyde, respectively, compared with that in the control. The ecotoxicity of formaldehyde caused the irreversible loss of current with 3% (1 ppm) and 81% (10 ppm). Confocal laser scanning microscopy and scanning electron microscopy results showed that the redox activity was inhibited by formaldehyde, and the number of dead/broken cells increased from 2% to 40% (1 ppm) and 91% (10 ppm). The contents of the total protein and extracellular polymer substances decreased by more than 28% (1 ppm) and 75% (10 ppm) because of the cleavage reaction caused by formaldehyde. Bacterial community analysis showed that the proportion of Geobacter decreased from 81% to 53% (1 ppm) and 24% (10 ppm). As a result, the current production was significantly impaired, and the irreversible loss increased. Toxicological analysis demonstrated that formaldehyde disturbed the physiological indices of cells, thereby inducing apoptosis. These findings fill the gap of ecotoxicology of toxicants to EAB in a bioelectrochemical system.