Abstract Biofilm formation on antifouling coatings is a serious concern in seawater cooling systems and the maritime industry. A prolific biofilm forming strain (Staphylococcus lentus), possessing high tolerance (>1,000 µg ml−1) to dissolved copper ions (Cu++) was isolated from titanium coupons exposed in the coastal waters of Kalpakkam, east coast of India. S. lentus formed increased biofilm (p < 0.05) at 100 µg ml−1 of Cu++ ions, when compared with the untreated control. To combat biofilm formation of this strain, the efficacy of copper oxide nanoparticles synthesized from copper nitrate by varying the concentrations of hexamine and cetyl trimethyl ammonium bromide (CTAB), was investigated. Complete (100%) inhibition of biofilm formation was observed with plain CuO NP (0.5 M hexamine, uncapped) at 1,000 µg ml−1. Capping with CTAB, influenced the morphology and the purity of the synthesized CuO NPs but did not alter their surface charge. Capping reduced metal ion release from CuO NPs and their antibacterial and anti-biofilm property against S. lentus. Overall, uncapped CuO NPs were effective in controlling biofilm formation of S. lentus. Concurrent release of copper ions and contact mediated physical damage by CuO NPs offer a promising approach to tackle metal tolerant biofilm bacteria.

中文翻译：

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氧化铜纳米粒子作为一种有效的抗生物膜剂对抗耐铜海洋细菌，迟缓葡萄球菌

摘要 防污涂层上的生物膜形成是海水冷却系统和海运业的一个严重问题。从暴露在印度东海岸卡尔帕卡姆沿海水域的钛试样中分离出一种多产的生物膜形成菌株（迟缓葡萄球菌），对溶解的铜离子 (Cu++) 具有高耐受性 (>1,000 µg ml-1)。与未处理的对照相比，迟缓链球菌在 100 µg ml-1 的 Cu++ 离子下形成增加的生物膜（p < 0.05）。为了对抗该菌株的生物膜形成，研究了通过改变六胺和十六烷基三甲基溴化铵 (CTAB) 的浓度由硝酸铜合成的氧化铜纳米颗粒的功效。使用 1,000 µg ml-1 的普通 CuO NP（0.5 M 六胺，未加盖）观察到完全 (100%) 抑制生物膜形成。用 CTAB 封顶，影响合成的 CuO NPs 的形态和纯度，但没有改变它们的表面电荷。从 CuO NPs 中减少金属离子的释放及其对 S. lentus 的抗菌和抗生物膜特性。总体而言，未加帽的 CuO NPs 可有效控制 S. lentus 的生物膜形成。CuO NPs 同时释放铜离子和接触介导的物理损伤为解决金属耐受性生物膜细菌提供了一种有前景的方法。