Abstract:
Nanostructure materials have attracted a great deal of attention because of their potential for achieving specific processes and selectivity, especially in biological and pharmaceutical applications. Of all kinds of metal nanoparticles, synthesis of silver nanoparticles is of considerable interest due to their wide range of applications in different fields. Chemical, physical and biological methods have been introduced for the synthesis of these nanoparticles. Offering reliable and eco-friendly processes for biological synthesis of metallic nanoparticles (using microorganisms) is an important step in nanobiotechnology. So far, different kinds of bacteria have been reported to be used for synthesis of silver nanoparticles. Escherichia coli bacteria is one of the earliest bacteria for this purpose. Studies showed that generally the presence of nitrate reductase enzyme is essential for the biosynthesis of silver nanoparticles using bacteria. Therefore, this enzyme and its relationship with the synthesis of silver nanoparticles have been studied in the present research work.
Machine summary:
Nitrate reductase enzyme in Escherichia coli and its relationship with the synthesis of silver nanoparticles Bahareh Khodashenas 1* 1 Department of Chemical Engineering, Shahrood Branch, Islamic Azad University, Shahrood ,Iran *Corresponding author’s E-mail: bahar.
Studies showed that generally the presence of nitrate reductase enzyme is essential for the biosynthesis of silver nanoparticles using bacteria.
Original Article: Received 25 Sep. 2014 Accepted 20 Nov. 2014 Published 30 Mar. 2015 Keywords: Silver nanoparticles,Escherichia coli, Synthesis, optimization, Nitrate reductase 1.
However, the general mechanism, usually accepted for biosynthesis of silver nanoparticles is the presence of Nitrate reductase enzyme [8].
In the present article the NR enzyme in Escherichia coli , its relationship with the synthesis of silver nanoparticles, and optimization of the medium culture are investigated to achieve the highest yield.
Ghorbani (2013) investigated the synthesis of silver nanoparticles by reduction of aqueous Ag+ ions with the culture supernatant of Escherichia coli (DH5a).
The probable mechanism for the formation of silver nanoparticles involves the NADH- dependent nitrate reductase enzyme that may convert Ag+ to Ag0 through electron shuttle enzymatic metal reduction process, shown in Fig. 3 [8].
As mentioned before, the Nitrate Reductase enzyme, released by microorganisms, is a major factor in the synthesis of silver nanoparticles.
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