WIU-BIO Research Renderings
Friday, October 25, 2013
Chemically Defined Medium as a Set Standard for Growth of Leuconostoc
Leuconostoc is a non-pathogenic, aero-tolerant anaerobic bacterial genus that lives on vegetation.
Leuconostoc plays an important role in industrial and food fermentations. Leuconostoc is often used for physiological and genetic studies related to polymer production. Typically, a complex nutrient source comprised of beef and yeast extracts is used to support the growth of Leuconostoc, however, the exact chemical composition of the nutrient source remains uncertain and therefore may result in less desirable growth patterns than a defined nutrient source. WIU undergraduate student, Megan McGlone has risen to the challenge for her undergraduate honors research project to determine if a defined nutrient source can serve as a suitable alternative to a complex nutrient source for growth of Leuconostoc. To accomplish the research goal, Megan will cultivate Leuconostoc species for 12 hours in a defined nutrient source and a complex nutrient source. Bacterial growth in each nutrient source will be determined through two methods called viable plate count (quantitative) and spectrophotometry (qualitative). Growth rates (m h-1) and bacterial colonies formed per milliliter of culture broth (CFU/ml) will be calculated from the quantitative viable plate count. Spectrophotometry will be used as a real-time growth assessment to monitor the progress of each growth experiment. Data indicating that there is no statistical difference in growth between each nutrient source would support the use of defined as a suitable alternative to complex. In addition, data indicating an increase in growth for the defined would also support its use as an alternative to complex. Megan's research advisor is Dr. Scott Holt.
Friday, August 23, 2013
Do Reduced Parasite Loads Contribute to Higher Abundances of Deer Mice?
Jonathan working overtime in the lab |
Parasites are known to harm their
hosts as they derive benefit, but are they capable of influencing the density
and dynamics of their host populations? Deer
mice (Peromyscus maniculatus) are
known to increase in abundance 2-5 times after a fire, but explanations for
this increase remained unknown. WIU
graduate student, Jonathan Vaughn recently completed a study to investigate whether
parasite load may be a factor to explain increased abundance of deer mice in
post-burned forest. Jonathan conducted
an exhaustive survey for all ectoparasites (fleas, ticks and lice) and
endoparasites (i.e., nematodes and cestodes) of specimens collected from a
burned and unburned area of forest in western Montana. Although no significant difference was found
between the endoparasites from the two areas, the mean abundance of
ectoparasites was lower in burned forest than unburned forest, especially for
fleas, which exhibited a 70% reduction.
It’s possible that the improved healthy condition of deer mice from
burned forest results in increases in abundance relative to their more heavily
parasitized brethren from the unburned forest.
This study was conducted in
collaboration with Rafal Zwolak and Sylwia Dziemian of the Adam Mickiewicz
University (Poland) and Elizabeth Crone of Harvard Forest, Harvard University
and under the guidance and mentorship of Jonathan’s graduate advisor, Dr. Shawn
Meagher. Jonathan has recently
graduated and accepted a position as adjunct faculty at the WIU School of
Agriculture.
A female flea, Aetheca wagneri
|
Sunday, April 21, 2013
Fungal Communities in Bats at Risk of White-Nose Syndrome in Caves and Mines in Southern Illinois
Indiana bat with white-nosed syndrome |
Tabitha Williams |
WIU graduate student, Tabitha Williams recently conducted a
study in an attempt to identify, characterize and compare psychrophilic fungal
communities associated with seven different bat species commonly found in
southern Illinois. The purpose of the
study is to provide important base-line data for bats, which live in caves that
have not yet been infected with a relatively new and emerging fungus Geomyces destructans, which causes
white-nose syndrome. White-nose syndrome
infects hibernating bats and has been responsible for major declines of bat
populations in eastern North America due to an increase in frequency of
arousals from torpor during hibernation leading to depletion of the fat
reserves and subsequent starvation.
Using the genetic ITS rDNA barcode, fungal communities in southern
Illinois were found to be dominated mostly by Ascomycota, followed by
Zygomycota, and Basidomycota. Nineteen
isolates were identified as Geomyces
strains with a high genetic similarity to G.
destructans. Most studies only examine bats in caves
after they have been infected with G.
destructans, but it is important to
understand fungal community structure before bats are infected to provide a
framework for how communities are altered after infection. This study was conducted in collaboration
with Robert McCleery of the University of Florida and Rod McClanahan of the
United States Forest Service, Shawnee National Forest and under the guidance
and and mentorship of Tabitha’s graduate advisor, Andrea
Porras-Alfaro.
Friday, April 19, 2013
Forest Bee Diversity in Relation to Habitat and Vertical Stratification
Augochlora pura, an abundant species |
Many studies in tropical rain forests have shown that insect
diversity in the canopy can differ markedly from diversity in the
understory. Surprisingly, relatively few
studies have explored such diversity in temperate deciduous forests. WIU graduate student, Jared Ruholl recently
completed a study investigating differences in bee species composition between
the canopy and in the understory and between early successional and oak/hickory
Midwestern forest habitats. He and his
collaborator James Zweep, an undergraduate honors student, collected 4,611 bee specimens comprised of 76
species. Agapostemon virescens, Lasioglossum macoupinense, and L. smilacinae were associated with
oak’/hickory understory, while Certina
calcarata and L. versatum were
associated with oak/hickory canopy. This
study is the first to document that bee diversity in Midwestern deciduous
forests exhibits substantial spatial variation.
This study was conducted under the guidance and mentorship of Jared’s
graduate advisor, Dr.
Kenneth McCravy.
Jared Ruholl working with two undergraduate students, Angela Walker (left) and Jamela Thompson (right) |
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