Herein, we employed the hydrogen-producing hyperthermophilic bacterial strain Caldicellulosiruptor changbaiensis for preparing uniform and size-tunable gold nanoparticles (AuNPs). Compared with the commonly used chemically synthesized nanoparticles, the biological synthesis of nanoparticles appears to be a suitable process since it has a low manufacturing cost of scalability, good biocompatibility, and better nanoparticles stabilization. The produced AuNPs possessed a unique property, whereby the smallest AuNPs exhibited the highest peroxidase activity over a broad pH range, even at neutral pH, which was quite different from the commonly chemical-synthesized ones. Also, when the size of AuNPs increased, the peroxidase activity of B-AuNPs at neutral pH decreased. Owing to the excellent antibacterial capability of ROS, the AuNPs exhibited striking antibacterial properties against both Gram-positive and Gram-negative bacteria, and moreover, the AuNPs showed excellent ability to disperse bacterial biofilms both in vitro and in vivo. Our studies indicate that living bacterial cells, as a biosynthesizer, can synthesize size-controllable AuNPs with improved bioactivity. This work may promote the design and synthesis of other types of metal nanoparticles with defined properties for future applications.

中文翻译：

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产氢高温嗜热细菌合成了尺寸可控的金纳米颗粒，具有出色的生物膜和抗菌应用消灭能力†

在这里，我们使用了产氢的超嗜热细菌菌株长白ensis（Caldicellulosiruptor）用于制备均匀且尺寸可调的金纳米颗粒（AuNPs）。与常用的化学合成纳米颗粒相比，纳米颗粒的生物合成似乎是合适的方法，因为它具有较低的可扩展性制造成本，良好的生物相容性和较好的纳米颗粒稳定性。产生的AuNP具有独特的特性，最小的AuNP即使在中性pH值下，也能在较宽的pH范围内显示出最高的过氧化物酶活性，这与通常的化学合成方法大不相同。另外，当AuNPs的大小增加时，B-AuNPs在中性pH下的过氧化物酶活性降低。由于ROS具有出色的抗菌能力，AuNPs对革兰氏阳性细菌和革兰氏阴性细菌均显示出惊人的抗菌性能，此外，体外和体内。我们的研究表明，活细菌细胞作为一种生物合成器，可以合成具有可改善的生物活性的大小可控的AuNP。这项工作可以促进具有定义的特性的其他类型的金属纳米粒子的设计和合成，以供将来应用。