Isolation and characterization of native fungi from contaminated ecosystems for the bioremediation of arsenic
Abstract
Environmental contamination by the heavy metal arsenic is among the most pressing pollution problems today due to its pervasive presence from anthropogenic and natural sources and its broadly-acting toxic effects. Fungi are being increasingly investigated for mycoremediation due to their abilities to remove, sequester, and/or detoxify arsenic by more efficient and environmentally sound methods than traditional metal remediation. This thesis contains three chapters: (I) A literature review that puts recent research into context by exploring properties and sources of arsenic and its modes of cellular toxicity, and by providing evidence that fungi can alleviate arsenic contamination by examining their cellular response mechanisms; (II) A study of the tolerance to arsenic exhibited by forty-nine fungal isolates collected from metal-contaminated sites in La Crosse, Wisconsin, and an investigation of the relationship between evolutionary lineage and arsenic tolerance, with results indicating a remarkably high degree of tolerance for all isolates and that ascomycetous fungi may have the highest tolerance; (III) A study of the cellular remediation mechanisms exhibited by four fungal isolates with statistically different tolerance levels, with results suggesting that despite their dissimilar tolerances, they responded in a similar fashion on a cellular level. Proposals for future work and experiments are included.
Subject
Soils -- Wisconsin
Bioremediation -- Wisconsin
Fungi -- Wissonsin