Production of silver nanoparticles using yeasts and evaluation of their antifungal activity against phytopathogenic fungi

JORGE G. FERNÁNDEZ; MARTÍN A. FERNÁNDEZ BALDO; ELÍAS BERNI; GERARDO CAMÍ; NELSON DURÁN; JULIO RABA; MARÍA I. SANZ

PROCESS BIOCHEMISTRY - (Print)

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2016 vol. 51 p. 1306 - 1313

1359-5113

The present study aimed to investigate the biological synthesis, characterization and antifungal activity of silver nanoparticles (Ag NPs). The production of Ag NPs was carried out using culture supernatants of two yeasts: Cryptococcus laurentii and Rhodotorula glutinis. These yeasts were chosen for their activity of nitrate reductase. The role of the mentioned enzyme in the production of nanoparticles was assessed by using inhibitors. The characterization of produced Ag NPs was made by UV-visible spectrophotometry, photon correlation spectroscopy, transmission electron microscopy and X-ray diffraction. Moreover, the stabilizing agents that surround the Ag NPs were identified by FTIR spectrum. The Ag NPs obtained from both yeasts were disperse and stable and showed differences in sizes, zeta potential, concentration and surrounding compounds. The antifungal activity of Ag NPs was evaluated against relevant phytopathogenic fungi, commonly producers of postharvest diseases. Tests ?in vitro? showed that, the antifungal activity of nanoparticles from R. glutinis was higher than the ones from C. laurentii and both were significantly more effectives for inhibiting the fungi that the nanoparticles of chemical synthesis. At one concentration of 3 ppm, nanoparticles from R. glutinis were similarly effectives than iprodione, a fungicide commonly utilized for combating postharvest diseases.