Small RNAs as a New Platform for Tuning the Biosynthesis of Silver Nanoparticles for Enhanced Material and Functional Properties

Abstract

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 Deinococcus radiodurans. 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.

PNPase and RhlB Interact and Reduce the Cellular Availability of Oxidized RNA in Deinococcus radiodurans

“…In the past, extensive studies have been conducted to understand the mechanism of the resistance of D. radiodurans to oxidative stresses, most of which mainly focused on gene regulation, protein functions, and sRNA regulations ( 38 , 39 , 46 , 50 – 52 ). Our previous work has revealed that ionizing radiation can cause a significantly increased 8-oxoG-RNA concentration in D. radiodurans ( 39 ).…”

Advances in the Application of Nanomaterials as Treatments for Bacterial Infectious Diseases

“…Inorganic nanomaterials with direct bactericidal effects include calcium silicate (CaSi) [15,21], silver (Ag) [22,23], copper (Cu) [24,25], and gold (Au) NPs [17,18]. Among the inorganic nanomaterials, Ag NPs have been one of the most widely used antimicrobial materials due to their broad-spectrum antibacterial capacity and low propensity to engender drug resistance [18].…”

“…Among the inorganic nanomaterials, Ag NPs have been one of the most widely used antimicrobial materials due to their broad-spectrum antibacterial capacity and low propensity to engender drug resistance [18]. Ag NPs had a good antimicrobial effect in both gram-positive and gram-negative bacteria, for example methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), Pseudomonas aeruginosa, and Klebsiella pneumoniae [18,22,23]. Au NPs have been shown to decrease the effect of lipopolysaccharide (LPS), an important toxin in gram-negative bacteria that causes fulminant immune responses through its effect on dendritic cells and immune reactions [26].…”

Radiation-resistant bacteria in desiccated soil and their potentiality in applied sciences

“…Rr bacteria resist osmotic and acid stress temperature variation and have a pool of enzymes, making them a suitable candidate in fermentation biotechnology. In addition, Rr bacteria exhibit tolerance to heavy metals, playing a crucial role in the bioremediation of pollutants and the biodegradation of radioactive and radionucleotide waste ( Luo et al, 2014 ; Beblo-Vranesevic et al, 2017 ; Chen et al, 2021 ; Nayak et al, 2021 ; Kumar et al, 2022 ). Furthermore, Rr bacteria produce various extremolytes, and their potential sunscreen ability is already commercialized and effectively utilized by skincare industries ( Mendes-Silva et al, 2020 ).…”