Biogenic synthesis and characterization of gold nanoparticles by a novel marine bacteria Marinobacter algicola: Progression from nanospheres to various geometrical shapes

Abstract

Metal nanoparticle biosynthesis is gaining impetus as the process is cost-effective and ecofriendly with a variety of application of them in biomedical field. In this study, biosynthesis approach for the synthesis of gold nano particles (GNPs) has been investigated using marine bacteria, Marinobacter algicola isolated from Indian sector of Southern Ocean. The biosynthesis of GNP was the obtained by adding HAuCl4-1mM, to the bacterial cell lysate supernatant (CLS) maintained at pH 7.0, incubated at 30 °C for 24 h. The bio-reduction of auric chloride was supposedly accomplished by enzyme nitrate reductase from the bacterial cellular bio mass, and was established using the FTIR data. GNP characterization from SEM, AFM and TEM exhibited formation of various shaped GNPs like spherical, triangular, pentagonal and hexagonal, possibly from enzyme nitrate reductase which is relatively different from GNPs synthesized so far reporting only single shape from single enzyme. XRD analysis determined the FCC structure of GNPs. DLS result display the GNPs formed is of mean size of 4-168 nm with an average of 74 nm. Being able to control the shapes of nanoparticles as a time dependent factor can be considered path breaking leading to its multipurpose biomedical application. The present research also studied the antimicrobial effect of GNPs on various pathogens.