Biosynthesis of silver nanoparticles by a new strain of Streptomyces sp. compared with Aspergillus fumigatus

Abstract

Locally isolated strains of a thermoalkalotolerant Streptomyces sp. and Aspergillus fumigatus were used for the in vitro biosynthesis of silver nanoparticles from AgNO(3) solutions. An autolysed cell-free culture filtrate from each strain was used, indicating that the formation mechanism depends on intra-cellular components for both organisms, since culture broths had no significant nanoparticle formation potential. Nanoparticle formation was indicated by a change of the solution from colourless or light brown to dark brown after 24 h or more, and UV-visible spectroscopy and x-ray diffraction analysis confirmed the formation by both organisms. The initial formation kinetics were faster with Aspergillus, but formation continued for a longer period with Streptomyces, resulting in higher concentrations after 48 h. Transmission electron microscope images revealed well dispersed nanoparticles with diameters ranging from 15 to 45 nm from A. fumigatus, while those from Streptomyces sp. had a narrower size distribution of 15-25 nm. The higher productivity and preferred narrower size distribution of Streptomyces, together with its well established industrial use, may make it the preferred choice for further optimization studies.

Antimicrobial activity of biosilver nanoparticles produced by a novel Streptacidiphilus durhamensis strain

“…Brown color is the result of excitation of surface plasmon vibration typical for Ag nanoparticles. 23,24 A peak close to 420 nm associated with the surface plasmon resonance is well-documented for various metal nanoparticles with sizes ranging from 2 nm to 100 nm. 15,24 …”

Marine sponge extract assisted biosynthesis of silver nanoparticles

“…[15], Eichornia crassipes [16], Syzygium aromaticum [17], Annona squamosa [18], Dioscorea bulbifera [19], Arbutus unedo [20], Streptomyces spp. [21] and Rhodococcus spp. [22] etc., we are proud to report for the first time of biosynthesis of silver nanoparticles using the marine sponge A. elongate.…”

Extremophile Current Challenges and New Gate of Knowledge by Nanoparticles Pathways.

“…ComparedwithStreptomyces sp.,Aspergillus fumigatusshows high efficiencyin stability of Ag-NPs production and size (range between 15-45 nm). Further information, the capping of NPs reduce Ag by passing the mechanism of NADH-reductase [88].Cryptococcus laurentii producing an extracellular stable Ag-NPs by the supernatant of cell-free, however, the psychrotrophic yeast such as Yarrowia lipolytica NCYC 789 producingan intracellular Ag-NPsunder submerged condition in the medium containing yeast nitrogen base glucose [89,90] BacillusNARW11 was able to produce titanium oxideat pH 2 with a tolerate temperature at 50°C that used for fluoride adsorption [91].Alcaligenesfaecalishas efficient ability to produce antimicrobial Ag-NPs under condition of alkali tolerantand non-nitrate reduction [92,93].The synthesisprocess of cell-free supernatant was optimized at 60 °C and at pH 10. Attenuated total reflection-Fourier transform infrared spectroscopy(ATR-FTIR) was used for determination of the existence of stabilizing NPs in capping protein [93].…”