Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China.
Environ Sci Pollut Res Int. 2018 Jan;25(3):2853-2860. doi: 10.1007/s11356-017-0616-8. Epub 2017 Nov 15.
In this study, we evaluated the influences of graphene oxide (GO) on biofilm formation. Escherichia coli MG1655 and Bacillus subtilis 168 were used as models for Gram-negative and Gram-positive bacteria. The growth profiles and viability assays indicated that GO exhibited a high antibacterial activity, of which the negative effects on bacteria growth raised with the increasing GO concentration. The antibacterial activity of GO was mainly attributed to the membrane stress and ROS-independent oxidative stress. Moreover, it was worthy to note that the biofilm formation was enhanced in the presence of GO at low dosage whereas inhibited in the high-concentration GO environment. These results could be explained by the roles of the dead cells, which were inactivated by GO. When the concentration of GO was limited, only a part of the cells would be inactivated, which may then serve as a protection barrier as well as the necessary nutrient to the remaining living cells for the formation of biofilm. In contrast, with a sufficient presence of GO, almost all cells can be inactivated completely and thus the formation of biofilm could no longer be triggered. Overall, the present work provides significant new insights on the influence of carbon nanomaterials towards biofilm formation, which has far-reaching implications in the field of biofouling and membrane bioreactor. Graphical abstract ᅟ.
在本研究中，我们评估了氧化石墨烯（GO）对生物膜形成的影响。大肠杆菌 MG1655 和枯草芽孢杆菌 168 被用作革兰氏阴性菌和革兰氏阳性菌的模型。生长曲线和生存能力测定表明，GO 表现出很高的抗菌活性，随着 GO 浓度的增加，其对细菌生长的负面影响增加。GO 的抗菌活性主要归因于膜应激和 ROS 非依赖性氧化应激。此外，值得注意的是，在低剂量 GO 存在下，生物膜形成得到增强，而在高浓度 GO 环境下则受到抑制。这些结果可以用失活细胞的作用来解释。当 GO 的浓度有限时，只有一部分细胞会失活，这可能成为剩余存活细胞形成生物膜的保护屏障和必要养分。相反，当有足够的 GO 存在时，几乎所有的细胞都可以被完全失活，从而不再触发生物膜的形成。总的来说，本工作为碳纳米材料对生物膜形成的影响提供了重要的新见解，这对生物污垢和膜生物反应器领域具有深远的意义。
