Baker Syed, Mohan Kumar K, Santosh P, Rakshith D, Satish S
Herbal Drug Technological Laboratory, Department of Studies in Microbiology, University of Mysore, India.
Trace Elements Speciation Research Laboratory, Environmental and Analytical Chemistry Division, School of Advanced Sciences, VIT University, Vellore, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2015 Feb 5;136 Pt C:1434-40. doi: 10.1016/j.saa.2014.10.033. Epub 2014 Oct 19.
In present investigation extracellular synthesis of silver nanoparticles were synthesized using cell free supernatant of Pseudomonas veronii AS41G isolated from Annona squamosa L. The bacterium significantly reduced silver nitrate to generate silver nanoparticles which was characterized with hyphenated techniques. Synthesis of silver nanoparticles preliminary confirmed by UV-Visible spectrophotometry with the intense peak at 410nm, Further FTIR analysis revealed the possible role of biomolecules in the supernatant responsible for mediating the nanoparticles formation. The XRD spectra exhibited the characteristic Bragg peaks of 100, 111, 200, and 220 facets of the face centred cubic symmetry of nanoparticles suggesting that these nanoparticles were crystalline in nature. TEM microgram showed polydispersity of nanoparticles with size ranging from 5 to 50nm. Synthesized silver nanoparticles showed antibacterial activity against human and environmental pathogens including MRSA. The study enlightens the role of biosynthesized silver nanoparticles as an emerging alternative for drug resistant microorganisms. The obtained results are promising enough to pave the environmentally benign nanoparticle synthesis processes without use of any toxic chemicals and also envision the emerging role of endophytes towards synthesis of nanoparticles. With scanty reports available on P.veronii species, a new role has been reported in this study which will be very valuable for future researchers working on it.
在本研究中，利用从番荔枝中分离出的维罗纳假单胞菌AS41G的无细胞上清液进行了银纳米颗粒的胞外合成。该细菌能显著将硝酸银还原以生成银纳米颗粒，并用联用技术对其进行了表征。银纳米颗粒的合成首先通过紫外可见分光光度法初步确认，在410nm处有强烈峰，进一步的傅里叶变换红外光谱分析揭示了上清液中生物分子在介导纳米颗粒形成中可能发挥的作用。X射线衍射光谱显示了纳米颗粒面心立方对称的100、111、200和220晶面的特征布拉格峰，表明这些纳米颗粒本质上是晶体。透射电子显微镜照片显示纳米颗粒具有多分散性，尺寸范围为5至50nm。合成的银纳米颗粒对包括耐甲氧西林金黄色葡萄球菌在内的人类和环境病原体具有抗菌活性。该研究揭示了生物合成的银纳米颗粒作为耐药微生物新兴替代物的作用。所获得的结果足以有望开辟不使用任何有毒化学物质的环境友好型纳米颗粒合成工艺，并且还设想了内生菌在纳米颗粒合成方面的新兴作用。鉴于关于维罗纳假单胞菌物种的报道稀少，本研究报告了一个新的作用，这对未来从事该研究的研究人员将非常有价值。
