AUTHOR=Nadhe Shradhda B. , Wadhwani Sweety A. , Singh Richa , Chopade Balu A. 

TITLE=Green Synthesis of AuNPs by Acinetobacter sp. GWRVA25: Optimization, Characterization, and Its Antioxidant Activity

JOURNAL=Frontiers in Chemistry

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.00474

DOI=10.3389/fchem.2020.00474

ISSN=2296-2646

ABSTRACT=<p>Bacteriogenic synthesis of metal nanoparticles is ecofriendly and greatly influenced by physico-chemical reaction parameters with respect to shape and size. Thus, present work aimed to synthesize and optimization of bacteriogenic gold nanoparticles (AuNPs) and study their antioxidant activity. <italic>Acinetobacter</italic> sp. cells were able to synthesize AuNPs, when challenged with tetra-chloroauric acid (HAuCl<sub>4</sub>). By physicochemical optimization, maximum synthesis was obtained with 72 h old culture using 2.1 × 10<sup>9</sup> CFU/ml cell density. Whereas, pH-7 is suitable for AuNPs synthesis. HAuCl<sub>4</sub> concentration (0.5 mM) enhanced the formation of monodispersed and spherical nanoparticles (15 ± 10 nm). At 37°C temperature, <italic>Acinetobacter</italic> sp. released nanoparticles in supernatant. From characterization, AuNPs were found to be crystalline in nature with negative surface charge. AuNPs showed up to 86% different radical scavenging ability, exhibiting antioxidant activity. In conclusion, spherical AuNPs can be synthesized using <italic>Acinetobacter</italic> sp. through physicochemical optimization. This is the first report of antioxidant activity exhibited by monodispersed bacteriogenic AuNPs synthesized using <italic>Acinetobacter</italic> sp.</p>