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Full-Text Articles in Organisms

Cyclic Peptides With Antifungal Properties Derived From Bacteria, Fungi, Plants, And Synthetic Sources, Naiera M. Helmy, Keykavous Parang Jun 2023

Cyclic Peptides With Antifungal Properties Derived From Bacteria, Fungi, Plants, And Synthetic Sources, Naiera M. Helmy, Keykavous Parang

Pharmacy Faculty Articles and Research

Fungal infections remain a significant concern for human health. The emergence of microbial resistance, the improper use of antimicrobial drugs, and the need for fewer toxic antifungal treatments in immunocompromised patients have sparked substantial interest in antifungal research. Cyclic peptides, classified as antifungal peptides, have been in development as potential antifungal agents since 1948. In recent years, there has been growing attention from the scientific community to explore cyclic peptides as a promising strategy for combating antifungal infections caused by pathogenic fungi. The identification of antifungal cyclic peptides from various sources has been possible due to the widespread interest in …


Cryptococcus Neoformans Melanization Incorporates Multiple Catecholamines To Produce Polytypic Melanin, Rosanna P. Baker, Christine Chrissian, Ruth E. Stark, Arturo Casadevall Dec 2021

Cryptococcus Neoformans Melanization Incorporates Multiple Catecholamines To Produce Polytypic Melanin, Rosanna P. Baker, Christine Chrissian, Ruth E. Stark, Arturo Casadevall

Publications and Research

Melanin is a major virulence factor in pathogenic fungi that enhances the ability of fungal cells to resist immune clearance. Cryptococcus neoformans is an important human pathogenic fungus that synthesizes melanin from exogenous tissue catecholamine precursors during infection, but the type of melanin made in cryptococcal meningoencephalitis is unknown. We analyzed the efficacy of various catecholamines found in brain tissue in supporting melanization using animal brain tissue and synthetic catecholamine mixtures reflecting brain tissue proportions. Solid-state NMR spectra of the melanin pigment produced from such mixtures yielded more melanin than expected if only the preferred constituent dopamine had been incorporated, …


Chytridiomycota In Tree Bark, Paige Strasko Dec 2020

Chytridiomycota In Tree Bark, Paige Strasko

Honors College

Chytridiomycota is a phylum of microscopic aquatic fungi that form motile spores that typically have a single posterior flagellum, thus they require water to disperse (James et al., 2000). Chytridiomycota, collectively called chytrids, have round shapes with structures called rhizoids that absorb nutrients and anchor them to their substrate (Mueller et al., 2004). Chytrids are typically found in aquatic environments and soils since zoospores require water to germinate (James et al., 2000), but they also have been found in a number of unexpected environments. Chytrids are difficult to find because they are microscopic and have time-sensitive life cycles (Mueller et …


A Biogeographical Assessment Of Arctic Marine Fungi, Bentley E. Simpson May 2020

A Biogeographical Assessment Of Arctic Marine Fungi, Bentley E. Simpson

Honors College

Marine fungi play a crucial role in recycling nutrients and channeling energy to higher trophic levels in the world oceans. Despite their critical role, their distributions and community composition, particularly in the Arctic, are largely unknown. This study reveals depth-related trends of abundance, diversity, and community composition of Arctic marine fungi through analysis of data obtained in the Tara Oceans expedition. With samples from surface (0-50 m), deep chlorophyll max (50-200 m), and mesopelagic (200-1000 m) depths, relative abundance, operational taxonomic unit (OTU) richness, and diversity were found to increase as a function of depth. Basidiomycota and Ascomycota were found …


The Biosorption Of Lead From Aqueous Solutions By A Wood-Immobilized Fungal Biosorbent, Zomesh A N Maini, Niña Therese B. Flores, Enrico P. Muñoz Dec 2019

The Biosorption Of Lead From Aqueous Solutions By A Wood-Immobilized Fungal Biosorbent, Zomesh A N Maini, Niña Therese B. Flores, Enrico P. Muñoz

Biology Faculty Publications

Lead [Pb(II)] biosorption capacities of immobilized Talaromyces macrosporus on Moringa oleifera L. wood were compared against pure fungal and pure M. oleifera biomass. A Pb(II) contact test of 1000 ug/mL show similar Pb(II) removal of non-immobilized fungal biomass (F) and powdered wood colonized with fungi (WP+F), with WP+F producing more biomass. Powdered sorbents had higher Pb(II) uptake compared to whole sorbents analyzed through ICP-AES, possibly due to increased surface area for Pb(II) binding. FTIR analysis of the F, WP, and WP+F identified hydroxyl, amino, carbonyl, and sulfhydryl functional groups which constitute probable Pb(II)-affinitive binding sites. The biosorbents tested in a …


Swainsonine Biosynthesis Genes In Diverse Symbiotic And Pathogenic Fungi, Daniel Cook, Bruno G. G. Donzelli, Rebecca Creamer, Deana L. Baucom, Dale R. Gardner, Juan Pan, Neil Moore, Stuart B. Krasnoff, Jerzy W. Jaromczyk, Christopher L. Schardl Jun 2017

Swainsonine Biosynthesis Genes In Diverse Symbiotic And Pathogenic Fungi, Daniel Cook, Bruno G. G. Donzelli, Rebecca Creamer, Deana L. Baucom, Dale R. Gardner, Juan Pan, Neil Moore, Stuart B. Krasnoff, Jerzy W. Jaromczyk, Christopher L. Schardl

Plant Pathology Faculty Publications

Swainsonine—a cytotoxic fungal alkaloid and a potential cancer therapy drug—is produced by the insect pathogen and plant symbiont Metarhizium robertsii, the clover pathogen Slafractonia leguminicola, locoweed symbionts belonging to Alternaria sect. Undifilum, and a recently discovered morning glory symbiont belonging to order Chaetothyriales. Genome sequence analyses revealed that these fungi share orthologous gene clusters, designated “SWN,” which included a multifunctional swnKgene comprising predicted adenylylation and acyltransferase domains with their associated thiolation domains, a β-ketoacyl synthase domain, and two reductase domains. The role of swnK was demonstrated by inactivating it in M. robertsii through homologous …


Fungal Melanin: What Do We Know About Structure?, Joshua D. Nosanchuk, Ruth E. Stark, Arturo Casadevall Dec 2015

Fungal Melanin: What Do We Know About Structure?, Joshua D. Nosanchuk, Ruth E. Stark, Arturo Casadevall

Publications and Research

The production of melanin significantly enhances the virulence of many important human pathogenic fungi. Despite fungal melanin’s importance in human disease, as well as melanin’s contribution to the ability of fungi to survive in diverse hostile environments, the structure of melanin remains unsolved. Nevertheless, ongoing research efforts have progressively revealed several notable structural characteristics of this enigmatic pigment, which will be the focus of this review. These compositional and organizational insights could further our ability to develop novel therapeutic approaches to combat fungal disease and enhance our understanding of how melanin is inserted into the cell wall.


Pseudomonas Aeruginosa-Candida Albicans Interactions: Localization And Fungal Toxicity Of A Phenazine Derivative, Jane Gibson, Arpanah Sood, Deborah A. Hogan Nov 2008

Pseudomonas Aeruginosa-Candida Albicans Interactions: Localization And Fungal Toxicity Of A Phenazine Derivative, Jane Gibson, Arpanah Sood, Deborah A. Hogan

Dartmouth Scholarship

Phenazines are redox-active small molecules that play significant roles in the interactions between pseudomonads and diverse eukaryotes, including fungi. When Pseudomonas aeruginosa and Candida albicans were cocultured on solid medium, a red pigmentation developed that was dependent on P. aeruginosa phenazine biosynthetic genes. Through a genetic screen in combination with biochemical experiments, it was found that a P. aeruginosa-produced precursor to pyocyanin, proposed to be 5-methyl-phenazinium-1-carboxylate (5MPCA), was necessary for the formation of the red pigmentation. The 5MPCA-derived pigment was found to accumulate exclusively within fungal cells, where it retained the ability to be reversibly oxidized and reduced, and its …