Growth of the fungus Chaetomium aureum in the presence of lead: implications in bioremediation

• Published in: Environmental earth sciences Vol. 77; no. 7; pp. 1 - 8
• Main Authors: Da Silva Júnior, Flavio Manoel Rodrigues, Volcão, Lisiane Martins, Hoscha, Laiz Coutelle, Pereira, Sônia Valéria
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2018; Springer Nature B.V
• Subjects: Biogeosciences; Bioprospecting; Bioremediation; Biosorption; Biotechnology; Carbon sources; Chaetomium aureum; Culture media; Earth and Environmental Science; Earth Sciences; Environmental Science and Engineering; Fungi; Geochemistry; Geology; Heavy metals; Hydrology/Water Resources; Inoculation; Inoculum; Lead; Microbiota; Oosporein; Organic chemistry; Original Article; Pectin; Soil; Soil contamination; Terrestrial Pollution; Brazilian semiarid; Trace metal; Filamentous fungi; Microcosm; Soil contamination
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-018-7447-x

Filamentous fungi were isolated from semiarid soil in which the lead (Pb) concentrations were above regulatory limits as determined by the Brazilian standards. Among these fungi, four isolates were tested for their abilities to grow in a culture medium containing lead nitrate. Chaetomium aureum was the species that presented a comparatively better performance including mycelial growth in a lead-containing medium, ability to use pectin as a carbon source, as well as basophilic and thermotolerant properties. The C. aureum inoculum with either activated or inactivated native microbiota was able to reduce the free Pb in soil (61 and 54%, respectively) after 60 days of inoculation. Although the mechanism involved in decreasing water-soluble and exchangeable lead concentrations in soil has not been studied, either the processes of biosorption by organic molecules (called oosporein, produced by this species) or fungal mineral transformation is among its possible explanations. These findings support the use of filamentous fungi as potential tools for the bioremediation of contaminated sites and highlight C. aureum as a promising tool for environmental biotechnology. In addition, the ability of this fungus (collected in a lead-contaminated area) to grow efficiently in the presence of this metal indicates that the bioprospecting strategy of the indigenous microbiota should be encouraged, as they appear to be more likely to succeed.