Toxicity of pentachlorophenol for micromycetes isolated from freshwater sediments

Abstract

In order to evaluate the impact of xenobiotics on fungal communities of sediments, lentic ecosystems have been reconstituted in the laboratory and examined before as well as after contamination.Microcosms (2 litres) have been treated with three different concentrations of pentachlorophenol (PCP) (3, 100, and 1000 mg 1-1) at 22 degC. The fungal strains present in the sediments were first isolated and identified before contamination with PCR Most of the strains belonged to Deuteromycetes (mainly Mucedinace~e and Dematiace~e) with a predominance of the genus Penicillium, and Ascomycetes were found in exceptional abundance. New isolations and identifications were made on days 1, 2, 4, 8, and 15 after contamination with PCP. The sensitivity of the various species were determined as a function of the level of PCP and the duration of contamination. Ascomycetes was particularly resistant to high concentrations of PCP. The toxicity of the xenobiotic towards strains belonging to various taxonomic groups is discussed, as well as the possibility that some of them may be useful for biodegradation and/or bioremediation processes, or as bioindicators of polluted sites.

Estudio de los mecanismos de remoción de pentaclorofenol por Rhizopus oryzae ENHE

“…Algunos hongos pertenecientes a los ascomicetos, zigomicetos, e inclusive deuteromicetos han logrado tolerar, degradar y mineralizar compuestos organoclorados. Sage et al, [65] aislaron sesenta y un cepas de micromicetos de sedimentos procedentes de yacimiento de agua dulce y estudiaron la capacidad de estos microorganismos para tolerar y crecer en presencia de PCF. Estos investigadores clasificaron las cepas fúngicas con base en su capacidad para sobrevivir o no a la presencia del tóxico, y encontraron que las cepas más tolerantes al PCF (1000 mg L -1 ) fueron cuatro ascomicetos (Eurotium repens, Pseudeurotium zonatum, Talaromyces trachyspermus y Talaromyces wortmanii) y un deuteromiceto (Scytalidium lignícola).…”