Twibell Brittany, Somerville Kalie, Manani Geoffrey, Duszynski Molly, Wanekaya Adam, Schweiger Paul
Biology Department, Missouri State University, Springfield, MO, United States of America.
Chemistry Department, Missouri State University, Springfield, MO, United States of America.
PeerJ. 2017 Aug 18;5:e3721. doi: 10.7717/peerj.3721. eCollection 2017.
The growing use of carbon nanotubes (CNTs) in industrial and consumer products raises important questions about their environmental fate and impact on prokaryotes. In the environment, CNTs are exposed to a variety of conditions (e.g., UV light) that could lead to decomposition and changes in their chemical properties. Therefore, the potential cytotoxic effect of both pristine and artificially aged carboxyl functionalized CNTRENE C100LM CNTmaterial at neutral and acidic conditions on K12 was analyzed using a minimal inhibitory concentration (MIC) assay, which also allowed monitoring of non-lethal growth effects. However, there were no observable MIC or significant changes in growth behavior in K12 when exposed to pristine or aged CNTs. Exposure to pristine CNTRENE C100LM CNT material did not appear to influence cell morphology or damage the cells when examined by electron microscopy. In addition, RNA sequencing revealed no observable regulatory changes in typical stress response pathways. This is surprising considering that previous studies have claimed high cytotoxicity of CNTs, including carboxyl functionalized single-walled CNTs, and suggest that other factors such as trace heavy metals or other impurities are likely responsible for many of the previously reported cytotoxicity in and possibly other microorganisms.
碳纳米管（CNTs）在工业和消费品中的使用日益增加，这引发了关于其环境归宿以及对原核生物影响的重要问题。在环境中，碳纳米管会接触到各种条件（例如紫外线），这些条件可能导致其分解并改变其化学性质。因此，使用最低抑菌浓度（MIC）测定法分析了原始的和人工老化的羧基官能化CNTRENE C100LM碳纳米管材料在中性和酸性条件下对K12的潜在细胞毒性作用，该方法还可以监测非致死性生长效应。然而，当K12暴露于原始的或老化的碳纳米管时，未观察到MIC或生长行为的显著变化。通过电子显微镜检查发现，暴露于原始的CNTRENE C100LM碳纳米管材料似乎不会影响细胞形态或损伤细胞。此外，RNA测序显示在典型的应激反应途径中未观察到调节变化。考虑到先前的研究声称碳纳米管具有高细胞毒性，包括羧基官能化的单壁碳纳米管，这一结果令人惊讶，并表明其他因素（如痕量重金属或其他杂质）可能是先前报道的对K12以及可能对其他微生物的许多细胞毒性的原因。
