Life Sciences Commons^™

Predation Thresholds In Marine Microbial Communities Applied To Environments With Low Prey Abundances, Bonnie Bailey

OES Theses and Dissertations

Prokaryotes (Bacteria and Archaea) comprise the largest component of biomass in the world's oceans. Their abundances are controlled by resource availability, viral infections and protist grazing. Many pico- and nano-eukaryotic predators grow almost as quickly as their prey, and greatly increase in numbers as soon as their prey do, leading in tum to depletion in prokaryotes. It is still unclear however, as to what extent microbial predators are able to feed in low prey environments, most prominently in the largest biome on Earth, the deep sea (below l 000 m depth). It has been hypothesized that in low prey environments, …

Characterization Of Metal-Reducing Microorganisms In Walker Lake: A Terminal Saline Desert Lake, Memona Khan

Honors College Theses

Metal-reducing microorganisms are increasingly being recognized as an essential component of aquatic microbial ecosystems involved in decomposition of organic matter. Alkaliphilic microbial reduction from alkaline lakes is a little studied field and one particular ecosystem, Walker Lake, presents the opportunity to investigate alkaliphilic metal reducers in their native ecological setting. Walker lake is a terminal, saline, desert lake with pH 9.4, Walker Lake samples of surface and deep sediments and water column samples from 0, 10, 5, 15, 17.5, 19 m depths were cultured by serial dilution in synthetic Walker Lake medium and supplemented separately with Hydrous Ferric Oxide (HFO), …

Dissolved Oxygen Content In Cedar Lake, Danielle Swanson, Angela Mccain, Paige White, Samuel Scherneck, Mark A. Gathany

The Research and Scholarship Symposium (2013-2019)

In an aquatic system, there is a balance between the production and consumption of oxygen. Oxygen is produced by photosynthetic microorganisms, and is taken directly from the atmosphere; it is consumed by the respiration of aquatic animals, decomposers, and a myriad of other chemical reactions. The biochemical oxygen demand (BOD) is the amount of oxygen consumed by organisms and is measured as dissolved oxygen (DO). DO concentrations are dependent upon temperature, wind and other physical factors, fluctuating diurnally.

In our experiment we will compare the DO concentrations at different depths in Cedar Lake. We will accomplish this by using a …

Impacts Of Climate Change On Soil Microorganisms In Northern Hardwood Forests, Carley Jane Kratz

Dissertations, Master's Theses and Master's Reports - Open

As global climate continues to change, it becomes more important to understand possible feedbacks from soils to the climate system. This dissertation focuses on soil microbial community responses to climate change factors in northern hardwood forests. Two soil warming experiments at Harvard Forest in Massachusetts, and a climate change manipulation experiment with both elevated temperature and increased moisture inputs in Michigan were sampled. The hyphal in-growth bag method was to understand how soil fungal biomass and respiration respond to climate change factors. Our results from phospholipid fatty acid (PLFA) analyses suggest that the hyphal in-growth bag method allows relatively pure …