Penicillium citreosulfuratum Isolated from Corroded Parts of a Hydroelectric Power Plant: Characterization and Control with Essential Oils

Abstract

: A Penicillium sp. strain was isolated from corroded parts in the Coaracy Nunes hydroelectric power plant in Amapá State, Brazil. Morphological and molecular techniques identified this strain as Penicillium citreosulfuratum Biourge, whose 5.8S-ITS rDNA sequence grouped well in a phylogenetic tree with other Exilicaulis section species of the Penicillium genus. The obtained strain of P. citreosulfuratum ability to form biofilm on the surface of aluminum wires was confirmed by optical and scanning electron microscopy. In plates containing PDA or T&K media, the P. citreosulfuratum strain growth was inhibited around a paper disk containing a highly concentrated solution of copper, iron, or nickel. However, there was no inhibition halo around the paper disk containing aluminum and there was a faint halo around the paper disk containing zinc. This fungus was able to grow in a modified T&K liquid medium containing 50 mM of Al 3+ and less efficiently in the same medium but containing 50 mM Zn 2+ . The essential oils of melaleuca, mint, thyme,