McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States.
Unidad Querétaro, Centro de Investigacion y de Estudios Avanzados Unidad Queretaro, Querétaro 76230, Mexico.
ACS Appl Mater Interfaces. 2021 Aug 11;13(31):36769-36783. doi: 10.1021/acsami.1c07400. Epub 2021 Jul 28.
Genetic engineering of nanoparticle biosynthesis in bacteria could help facilitate the production of nanoparticles with enhanced or desired properties. However, this process remains limited due to the lack of mechanistic knowledge regarding specific enzymes and other key biological factors. Herein, we report on the ability of small noncoding RNAs (sRNAs) to affect silver nanoparticle (AgNP) biosynthesis using the supernatant from the bacterium . Deletion strains of 12 sRNAs potentially involved in the oxidative stress response were constructed, and the supernatants from these strains were screened for their effect on AgNP biosynthesis. We identified several sRNA deletions that drastically decreased AgNP yield compared to the wild-type (WT) strain, suggesting the importance of these sRNAs in AgNP biosynthesis. Furthermore, AgNPs biosynthesized using the supernatants from three of these sRNA deletion strains demonstrated significantly enhanced antimicrobial and catalytic activities against environmentally relevant dyes and bacteria relative to AgNPs biosynthesized using the WT strain. Characterization of these AgNPs using electron microscopy (EM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) revealed that the deletion of these small RNAs led to changes within the supernatant composition that altered AgNP properties such as the surface chemistry, surface potential, and overall composition. Taken together, our results demonstrate that modulating specific sRNA levels can affect the composition of supernatants used to biosynthesize AgNPs, resulting in AgNPs with unique material properties and improved functionality; as such, we introduce sRNAs as a new platform for genetically engineering the biosynthesis of metal nanoparticles using bacteria. Many of the sRNAs examined in this work have potential regulatory roles in oxidative stress responses; further studies into their targets could help provide insight into the specific molecular mechanisms underlying bacterial biosynthesis and metal reduction, enabling the production of nanoparticles with enhanced properties.
在细菌中进行纳米颗粒生物合成的基因工程可以帮助生产具有增强或所需性质的纳米颗粒。然而，由于缺乏关于特定酶和其他关键生物因素的机制知识，这个过程仍然受到限制。在此，我们报告了小非编码 RNA (sRNA) 影响细菌. 用细菌上清液合成银纳米颗粒 (AgNP) 的能力。构建了可能参与氧化应激反应的 12 个 sRNA 缺失菌株，并筛选这些菌株的上清液对 AgNP 生物合成的影响。我们鉴定了几个 sRNA 缺失菌株，与野生型 (WT) 菌株相比，AgNP 的产量大大降低，这表明这些 sRNA 在 AgNP 生物合成中很重要。此外，与使用 WT 菌株合成的 AgNP 相比，使用这三个 sRNA 缺失菌株的上清液合成的 AgNP 对环境相关染料和细菌表现出明显增强的抗菌和催化活性。使用电子显微镜 (EM)、能量色散 X 射线光谱 (EDX)、X 射线光电子能谱 (XPS) 和 X 射线衍射 (XRD) 对这些 AgNP 进行表征，发现这些小 RNA 的缺失导致上清液成分发生变化，从而改变了 AgNP 的性质，如表面化学、表面电势和整体成分。总之，我们的结果表明，调节特定 sRNA 的水平可以影响用于生物合成 AgNP 的上清液的组成，从而产生具有独特材料特性和改善功能的 AgNP；因此，我们引入 sRNA 作为使用细菌遗传工程合成金属纳米颗粒的新平台。在这项工作中检查的许多 sRNA 可能在氧化应激反应中具有潜在的调节作用；对其靶标的进一步研究可以帮助提供对细菌生物合成和金属还原的具体分子机制的深入了解，从而能够生产具有增强特性的纳米颗粒。
