The goals of this research are to 1) ascertain the biodiversity of a phylogenetically diverse group of heterotrophic eukaryotes (the yeasts) in a changing and endangered environment (South Florida Everglades, Florida Bay and adjacent coral reefs) and 2) to evaluate the effects of environmental parameters and limiting nutrients (e.g., temperature, salinity, nitrogen, phosphorus and dissolved organic carbon) on yeast community structure.
The yeasts are unicellular organisms, which represent a phylogenetic diversity of fungi: two phyla, six classes, 29 orders or equivalent lineages, 90 genera and 1000 species. Despite these high numbers, the yeasts are an understudied group of organisms; estimates indicate that possibly only 1% of the yeasts in nature have been discovered. Yeasts have ecological, commercial and medical importance: fungi are primary drivers of the global carbon cycle and their use constitutes one of the world?`s largest industries. Consequently, species extinction with habitat loss can have considerable economic significance. Little is known, however, about yeast ecology, largely due to the inadequacies of yeast identifications. The recent introduction of molecular systematics has provided the tools for in-depth studies of the ecology and phylogeny of yeasts.
The South Florida ecosystem initiates at Lake Okeechobee with a southward water flow through the Everglades into Florida Bay with an interchange that connects the coral reefs. This interactive system has been managed and mis-managed for over 100 yrs and is being crowded by development. Concern over the fate of the region has resulted in on-going multi-agency, institutional environmental studies. Our program will coordinate with two of the largest studies, the Florida International University (FIU) NSF LTER site and NOAA?`s Florida Bay Program, to ascertain yeast community structure in diverse and changing environmental conditions.
Estimates indicate that a large number of new species will be discovered in the Everglades system. These new species will be evaluated with existing molecular phylogenetic schemes of ascomycetous and basidiomycetous yeasts for incorporation into a revised monograph of all described yeast species: The Yeasts, A Taxonomic Study 5th Edition. The revision will highlight a revolution in yeast systematics: conversion from phenotypic to molecular phylogeny.
Specific attention in this proposal is directed to electronic availability of data. The monograph is designed for web based access: strain, collection and phenotypic data will be on-line at the CBS website; molecular sequence data will be on GenBank; and ecological data will be available on the FCE LTER website, which is linked to the NOAA websites. Important strains of yeasts will be available at internationally recognized culture collections (USDA Peoria, Centraalbureau voor Schimmelcultures, Netherlands and American Type Culture Collection, Maryland). Training will include graduate and undergraduate students and interchange between investigators and students at international institutions.