Interference of non-lethal levels of graphene oxide in biofilm formation and adaptive response of quorum sensing in bacteria
Interference of non-lethal levels of graphene oxide in biofilm formation and adaptive response of quorum sensing in bacteria
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非致死水平的氧化石墨烯对细菌生物膜形成的干扰和群体感应的适应性反应
DOI：
10.1039/c8en00680f
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
徐峰
中科院分区：
文献类型：
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作者：
张芸芸;李娜;汪美贞;冯华军;徐超;徐峰
随着氧化石墨烯（GO）在产品和工艺中的应用越来越多，其生态安全性已成为人们迫切关注的问题。虽然GO的毒性已被广泛研究，但关于非致死水平的GO对生物膜形成和群体感应（QS）的影响的研究有限。在这里，铜绿假单胞菌PAO 1被用来评估非致死水平的GO对这些细菌社会行为的影响。短期暴露后，GO水平低于40 mg L−1不会影响种群繁殖，但会干扰生物膜的形成。虽然GO不改变QS相关基因的转录，但它吸收了QS信号N-3-氧代-十二烷酰基高丝氨酸内酯（3 OC 12-HSL）和QS调节的蛋白酶。3 OC 12-HSL的吸附是GO干扰挂膜的主要机制之一。在长期处理过程中，培养物中3 OC 12-HSL和蛋白酶的量逐渐增加。由于QS对GO暴露的适应性反应，GO介导的生物膜形成抑制在约160代繁殖后减少。我们得出结论，GO暴露的短期影响是不持久的，因为细菌适应GO吸附。在这方面，在非致死水平下GO处理没有不利的生态影响。
With the increasing use of graphene oxide (GO) in products and processes, its ecological safety has been raised as an urgent concern. Although the toxicity of GO has been widely investigated, research concerning the effects of non-lethal levels of GO on biofilm formation and quorum sensing (QS) is limited. Here, Pseudomonas aeruginosa PAO1 was employed to evaluate the effects of non-lethal levels of GO on these bacterial social behaviors. After short-term exposure, GO levels below 40 mg L−1 did not affect population propagation but did interfere with biofilm formation. Although GO did not change the transcription of QS-related genes, it adsorbed the QS signals N-3-oxo-dodecanoyl homoserine lactone (3OC12-HSL) and QS-regulated proteases. Adsorption of 3OC12-HSL was one of the main mechanisms by which GO interfered with biofilm formation. During long-term treatment, the amount of 3OC12-HSL and proteases in the culture increased gradually. The GO-mediated inhibition of biofilm formation was reduced after about 160 generations of propagation due to an adaptive response of the QS to GO exposure. We conclude that the short-term effects of GO exposure are not sustained because of bacterial adaptation to GO adsorption. In this regard, there is no adverse ecological impact from GO treatment under non-lethal levels.