Rodríguez Sartori Damián, Bertuola Marcos, Miñán Alejandro, Gonik Eduardo, Gonzalez Mónica C, Fernández Lorenzo de Mele Mónica
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), CCT La Plata, CONICET, Facultad de Ciencias Exactas, UNLP, C.C. 16 Suc. 4, 1900 La Plata, Argentina.
Facultad de Ingeniería, UNLP, B1900 La Plata, Argentina.
ACS Omega. 2021 Feb 17;6(8):5197-5208. doi: 10.1021/acsomega.0c05114. eCollection 2021 Mar 2.
The effects of environmental factors such as sunlight irradiation and the presence of humic acid (HA) on the physicochemical properties of commercial multiwall carbon nanotubes (MWCNT) suspended in a simulated inorganic matrix (SIM) and their impacts on bacteria growing in biofilms were evaluated. Both solar irradiation and the presence of HA lead to the dissolution of adsorbed metals on the MWCNT, which are residues of synthesis catalysts. Also, preferential adsorption of certain HA components on the MWCNT induces important modifications in the aliphatic/aromatic relationship of HA components in solution and the generation and release of new moieties. Results demonstrated that the variation of such physicochemical parameters strongly affects the interactions of MWCNT with sessile bacteria. Thus, the number of attached bacteria increased, and stress responses such as decrease in bacterial size were found in the presence of sunlight-irradiated MWCNT with a particular distribution of extracellular polymeric substances (EPS) strands. A shielding effect was observed when HA was added. It was concluded that physicochemical alterations caused by environmental conditions (with/without irradiation, presence/absence of HA) on MWCNT-containing SIM trigger distinctive adaptive behavior of bacteria in biofilms. This information must be taken into account in the development of biologically assisted treatments for organic metal co-contamination of MWCNT-containing media since MWCNT discharge alters the physicochemical properties and composition of the aqueous environment and the response of the biofilms that interact with it.
评估了阳光照射和腐殖酸（HA）的存在等环境因素对悬浮在模拟无机基质（SIM）中的商用多壁碳纳米管（MWCNT）物理化学性质的影响，以及它们对生物膜中细菌生长的影响。太阳辐射和HA的存在都会导致MWCNT上吸附的金属溶解，这些金属是合成催化剂的残留物。此外，某些HA成分在MWCNT上的优先吸附会引起溶液中HA成分的脂肪族/芳香族关系的重要变化，以及新部分的生成和释放。结果表明，这些物理化学参数的变化强烈影响MWCNT与固着细菌的相互作用。因此，在存在具有特定分布的胞外聚合物（EPS）链的阳光照射的MWCNT时，附着细菌的数量增加，并且发现了诸如细菌尺寸减小等应激反应。添加HA时观察到屏蔽效应。得出的结论是，环境条件（有/无辐射、有/无HA）对含MWCNT的SIM造成的物理化学改变引发了生物膜中细菌独特的适应性行为。在开发针对含MWCNT介质的有机金属共污染的生物辅助处理方法时，必须考虑到这一信息，因为MWCNT的排放会改变水环境的物理化学性质和组成以及与之相互作用的生物膜的反应。
