GREEN SYNTHESIS OF SELENIUM NANOPARTICULES WITH ANTIFUNGAL ACTIVITY AGAINST THE WOOD-ROTTING FUNGI Oligoporus pelliculosus

ORDÓÑEZ, OMAR FEDERICO; APARICIO, FRANCISCA; ZAPATA, CLAUDIA; PESCUMA, MICAELA

Los Cocos

Congreso; XVII Congreso Argentino de Microbiología General; 2022

SAMIGE

Nanoparticle (NP) synthesis of different sizes, shape and dispersive characteristics is gaining interestin nanotechnology. Nanoparticles are often produced by chemical methods using toxic chemicals andextreme physical conditions (high temperatures and/or pressures). The synthesis of biogenic NPs usingmicroorganisms is a low-cost green technology. These NPs are more stable and have greaterantimicrobial activity than those of chemical synthesis. NPs can improve the properties of wood suchas resistance to abrasion, ultraviolet rays, improve gloss, transparency and hydrophobicity, act as fireretardants and biocides. Recently, selenium nanoparticle (SeNPs) production has gained popularitydue to its low toxicity in humans and its high antioxidant, anticarcinogenic and antimicrobial capacity.It was also reported that SeNPs can inhibit the formation of bacterial biofilms and the developmentof fungi. The aim of our work was to study the ability of Delftia sp. 5 to produce SeNPs able to inhibitthe growth of the brown-rotting fungus, Oligoporus pelliculosus, in Nothofagus pumilio (Lenga) sawnwood. The Delftia sp. 5 resistance to Se and its ability to produce antifungal SeNPs was analyzed inthis work. The Delftia sp. 5 growth inhibition in the presence of selenite was determined by measuringthe optical density at 600 nm, while SeNPs production was determined by the change of color of theculture medium (yellow to red). The SeNPs concentration was determined by ICP-MS andcharacterized by transmission and electron microscopy (TEM and SEM), dynamic light scattering (DLS).Delftia sp. 5 showed an optimal SeNPs production when Se concentration was 160 mg l-1 and itsgrowth was inhibited at a concentration of 640 mg/L. Bacterial cell pellets Se concentration was 6.290± 0.163 mg l-1. The strain produced spherical nanoparticles with sizes between 83.00 ± 0.18 and151.00 ± 0.20 nm with a negative Z potential of -40 ± 2.00 mV. Moreover, SeNPs produced by Delftiasp. 5 (33.6 ± 0.107 mg l-1 Se) were shown to inhibit the growth of O. pelliculosus in agar plates and inLenga wood samples. Delftia sp. 5 SeNPs could be used for embedding Lenga wood previous to dryingfor preventing the growth of the deteriorating fungi O. pelliculosus by deteriorating fungi.