Characterization, antimicrobial, and antioxidant activities of silver nanoparticles synthesized by uricase from Alcaligenes faecalis GH3

Abstract

Abstract Enzyme-mediated nanoparticles synthesis has found promising attention by researchers. In this project, a powerful uricase-producing bacterium was screened from poultry soil samples which are generally rich in uric acid. GH3 isolate was identified as Alcaligenes -faecalis. Biosynthesis of AgNPs was done using the cell extract of A. faecalis GH3 treated with an aqueous solution of AgNO3. SEM results show that AgNPs were spherical in shape and were in size ranging from 32 to 49 nm. Also, the zeta potential of synthesized AgNPs in colloidal solution was −21 mV, which displays the good stability of the particles in the colloidal solution. Results showed that the maximum improvement in antibacterial activity of AgNPs mixed with antibiotic was about 162.5% for ampicillin against B. cereus, compared to antibiotic alone. Furthermore DPPH and ABTS+ radical scavenging activities showed increased activities with increasing concentration of AgNPs. IC50 values of AgNPs was obtained as 710 and 220 μg/ml for DPPH and ABTS+ scavenging activities, respectively. These results indicate that AgNPs synthesis by cell extract of uricase producing Alcaligenes has potent application in antibacterial and antioxidant approaches.