Isolation of fungi with potential for bioremediation from Osamu Utsumiuranium mine.

Author(s)

Ednei da Assunção Antunes Coelho

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2019-07-02

Examining board members

Benedito Correa; Felipe Santiago Chambergo Alcalde; Mário Henrique de Barros; Luciana Jandelli Gimenes; Jorge Timenetsky

• Advisor: Benedito Correa

Abstract

The Osamu Utsumi mine from Industrias Nucleares do Brasil (INB), located in the city of Caldas/MG, was the first uranium extraction mine in Brazil and closed its activities in 1995. Since then, it has problems in rehabilitating contaminated areas due to high levels of uranium contamination. In this regard, bioremediation emerged as an alternative technology for the remediation of sites contaminated with heavy metals. The aim of the present investigation was to isolated and characterized fungal species resistant to uranium from soil, water and sediment from Osamu Utsumi uranium mine and evaluated the uranium removal capacity from these microorganisms. The pH of the water samples was between 3.16 and 3.48. The uranium concentration from the samples was 58 to 268 mg/kg (soil), 1.05 to 4.46 mg/L (water) and 283 to 488 mg/kg (sediment). The mean water activity (Wa) of the soil samples was 0.98. From the samples, 57 fungi were isolated, with Penicillium being the most frequent species. In the tolerance tests, 38% (22) of the fungal isolates were considered tolerant to uranium, with emphasis on 5 Penicillium piscarium isolates. The mycelial growth rate revealed growth of 48 fungi at high concentrations of uranium tested (2000mg/L). Minimal inhibitory concentration (MIC) analysis showed growth of 25 fungi at concentrations of 8000 mg/L. Biosorption tests with live fungal biomass showed that 11 species were considered as having high potential for bioremediation of the uranium. When comparing the resistance/tolerance tests with uranium biosorption capacity, we concluded that the fungi isolated from the Osamu Utsumi mine with the best potential for uranium bioremediation were Gongronella butleri, Penicillium piscarium, Penicillium citrinum, Penicillium ludwigii, Talaromyces amestolkiae. (AU)

• FAPESP's process: 15/06757-1 - Isolation of fungi with potential for bioremediation of heavy metals and radionuclides in uranium mine Osamu Utsumi
• Grantee: Ednei Assunção Antunes Coelho
• Support Opportunities: Scholarships in Brazil - Doctorate