Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 8 of 8

Full-Text Articles in Life Sciences

Quantatative Analysis Of Microbial Abundance Within Arctic Fjord Sediments Assessed Through Direct Counting, Alex Taylor Swystun Dec 2017

Quantatative Analysis Of Microbial Abundance Within Arctic Fjord Sediments Assessed Through Direct Counting, Alex Taylor Swystun

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Microbes found in the marine sediments are responsible for the production of nearly half of the carbon dioxide found in the atmosphere (Arrigo, 2005). The fjords of Svalbard (79°N) are not considered typical marine sediments because high iron content influences unique subsurface redox chemistry. Radiotracer studies have shown that these sediments contain active bacterial sulfate-reducing communities (Finke et al., 2016). In addition to bacteria, archaeal cells within these sediments have been in aggregates encompassed by sulfate-reducing bacteria (Ravenschlag et al., 2001). These anaerobic organisms participate in mediating environmental biogeochemical cycles, including the oxidation of methane (Ravenschlag et al., 2001) and …


Evidence For The Priming Effect In Single Strain And Simplified Communities Of Estuarine Bacteria, Abigail Amina Edwards Dec 2017

Evidence For The Priming Effect In Single Strain And Simplified Communities Of Estuarine Bacteria, Abigail Amina Edwards

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Through their transformation of naturally occurring organic matter, coastal marine bacteria play an essential role in carbon cycling. A phenomenon termed the priming effect (PE) occurs when microbial communities remineralize recalcitrant organic matter faster in the presence of labile organic matter and may be prevalent in coastal systems. To understand how microbial community members interact to induce PE, it is essential to first understand the mechanisms underlying PE in single strains and simplified bacterial communities. The effect to which different concentrations and sources of labile carbon stimulated the production of bacterial biomass from riverine organic matter by two marine bacteria …


Bioinformatic And Experimental Approaches For Deeper Metaproteomic Characterization Of Complex Environmental Samples, Ramsunder Mahadevan Iyer Dec 2017

Bioinformatic And Experimental Approaches For Deeper Metaproteomic Characterization Of Complex Environmental Samples, Ramsunder Mahadevan Iyer

Doctoral Dissertations

The coupling of high performance multi-dimensional liquid chromatography and tandem mass spectrometry for characterization of microbial proteins from complex environmental samples has paved the way for a new era in scientific discovery. The field of metaproteomics, which is the study of protein suite of all the organisms in a biological system, has taken a tremendous leap with the introduction of high-throughput proteomics. However, with corresponding increase in sample complexity, novel challenges have been raised with respect to efficient peptide separation via chromatography and bioinformatic analysis of the resulting high throughput data. In this dissertation, various aspects of metaproteomic characterization, including …


Detection, Diversity, And Evolution Of Fungal Nitric Oxide Reductases (P450nor), Steven Adam Higgins Aug 2017

Detection, Diversity, And Evolution Of Fungal Nitric Oxide Reductases (P450nor), Steven Adam Higgins

Doctoral Dissertations

Nitrous oxide (N2O) is a gas responsible for significant ozone layer depletion and contributes to greenhouse effects in Earth’s atmosphere. N2O is primarily generated by denitrification, whereby nitrate (NO3-) or nitrite (NO2-) is converted to gaseous N2O or N2. Teragram quantities of N2O are emitted annually from agricultural soils treated with nitrogenous fertilizers due to the activity of soil microbiota. Although bacteria and fungi harbor genes permitting denitrification, fungi lack NosZ, an enzyme responsible for reducing N2O into inert N2 gas. Historically, scientists have linked fungi …


Managing Exoelectrogenic Microbial Community Development Through Bioprocess Control For Conversion Of Biomass-Derived Streams, Alex James Lewis Aug 2017

Managing Exoelectrogenic Microbial Community Development Through Bioprocess Control For Conversion Of Biomass-Derived Streams, Alex James Lewis

Doctoral Dissertations

Bioelectrochemical systems are an emerging technology capable of utilizing aqueous waste streams generated during biomass conversion of lignocellulosic feedstocks to produce valuable co-products and thus, have potential to be integrated into biorefineries. In a microbial electrolysis cell, organic compounds are converted to electrons, protons, and CO2 by fermentative and exoelectrogenic bacteria in the anode compartment. By having the ability to extract electrons from waste streams, these systems can treat water while also producing hydrogen, and thus can improve the efficiency of biomass to fuel production by minimizing external hydrogen requirement and enabling water recycle. The overall goal of this …


Ecological And Evolutionary Dynamics Of Plant-Soil Feedbacks: Influences On Evolution And Range Dynamics, Michael E. Van Nuland May 2017

Ecological And Evolutionary Dynamics Of Plant-Soil Feedbacks: Influences On Evolution And Range Dynamics, Michael E. Van Nuland

Doctoral Dissertations

Plants interact with, modify, and are affected by their soil environments. Though plant-soil interactions are well known to be important and active regulators of ecosystem function and community structure, much less is known about how these interactions affect plant evolution. The primary goal of my dissertation was to examine plant-soil interactions under a range of ecological and evolutionary contexts to better understand patterns of biodiversity, ecosystem function, and whole system responses to environmental change. Taking such an eco-evolutionary perspective allows for a holistic understanding of the causes and consequences of complex abiotic and biotic interactions that link ecosystem ecology and …


The Microbial Ecology Of Bacterial Lignocellulosic Degradation In The Ocean, Hannah Laing Yee Woo May 2017

The Microbial Ecology Of Bacterial Lignocellulosic Degradation In The Ocean, Hannah Laing Yee Woo

Doctoral Dissertations

The overarching theme of my dissertation is to study the role of bacteria in lignocellulose degradation. In recent years, more research has investigated the biodegradability of lignocellulose for biofuel production. The components of the lignocellulosic plant cell wall are considered intrinsically recalcitrant due to their structure. However, we hypothesize that these components are not intrinsically recalcitrant but their biodegradation is contingent on the environmental conditions, particularly the bacterial diversity. We believe bacteria will become especially important in lignocellulose degradation in conditions that are unfavorable for white-rot fungi. Therefore, we investigated the potential for lignin degradation by bacteria in the ocean …


A Bug’S Life: Integration Of Anaerobic Digestion And Bioelectrochemical Systems For Enhanced Energy Recovery From Wastewater Solids And Other Waste Substrates, Jeff Ryan Beegle May 2017

A Bug’S Life: Integration Of Anaerobic Digestion And Bioelectrochemical Systems For Enhanced Energy Recovery From Wastewater Solids And Other Waste Substrates, Jeff Ryan Beegle

Masters Theses

Organic waste streams, like domestic wastewater and municipal solid waste, have the potential to be used as feedstocks for biotechnology processes to produce high value products and energy. This thesis investigated the technological, economical, and environmental potential for integrated anaerobic digestion (AD) and bioelectrochemical system (BES) platforms as they were theoretically and physically evaluated for energy recovery from domestic wastewater. The first chapter of this thesis compared the theoretical energy efficiencies of converting waste directly into electricity, using AD and BES alone and in various combinations. This chapter reviewed the experimentally demonstrated energy efficiencies reported in the literature with comparisons …