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Full-Text Articles in Life Sciences

Constraints On Primary Production In Lake Erie, Matthew Alan Saxton May 2011

Constraints On Primary Production In Lake Erie, Matthew Alan Saxton

Doctoral Dissertations

The Laurentian Great Lake, Lake Erie is an invaluable global resource and its watershed is home to over 11 million people. The pressures placed on the lake because of this high population caused Lake Erie to experience numerous environmental problems, including seasonal hypoxia and harmful algal blooms. While these topics have been widely studied in Lake Erie for over 40 years a more nuanced understanding of the interaction between phytoplankton and nutrient is needed to properly address the problems continuing to face the lake. In this study we combine classical limnological and cell growth experiments with modern molecular biological techniques …


Genomic And Molecular Analysis Of The Exopolysaccharide Production In The Bacterium Thauera Aminoaromatica Mz1t, Ke Jiang May 2011

Genomic And Molecular Analysis Of The Exopolysaccharide Production In The Bacterium Thauera Aminoaromatica Mz1t, Ke Jiang

Doctoral Dissertations

Thauera aminoaromatica MZ1T is an exopolysaccharide (EPS)-producing Gram negative bacterium isolated from the wastewater treatment plant of a major industrial chemical manufacturer as the causal agent for poor sludge dewatering. It shares common features with other known Thauera spp. (i.e. Thauera aromatica, and Thauera selenatis), being capable of degrading aromatic compounds anaerobically and using acetate and succinate as carbon sources. It is unique among the Thauera spp. in its production of abundant EPS which results in viscous bulking and poor sludge dewaterability. In this respect, it is similar to Azoarcus sp. EbN1 and BH72. Thaueran is the proposed …


The ‘Helper’ Phenotype: A Symbiotic Interaction Between Prochlorococcus And Hydrogen Peroxide Scavenging Microorganisms, James Jeffrey Morris May 2011

The ‘Helper’ Phenotype: A Symbiotic Interaction Between Prochlorococcus And Hydrogen Peroxide Scavenging Microorganisms, James Jeffrey Morris

Doctoral Dissertations

The unicellular cyanobacterium Prochlorococcus is the numerically dominant photosynthetic organism throughout the temperate and tropical open oceans, but it is difficult to grow in pure cultures. We developed a system for rendering spontaneous streptomycin-resistant mutants of Prochlorococcus axenic by diluting them to extinction in the presence of “helper” heterotrophic bacteria, allowing them to grow to high cell concentrations, and then killing the helpers with streptomycin. Using axenic strains obtained in this fashion, we demonstrated that Prochlorococcus experiences a number of growth defects in dilute axenic culture, including reduced growth rate, inability to form colonies on solid media, and higher incidence …


Quantification And Ecological Perspectives On Cyanophage And Aquatic Viruses, Audrey Renee Matteson May 2011

Quantification And Ecological Perspectives On Cyanophage And Aquatic Viruses, Audrey Renee Matteson

Doctoral Dissertations

The field of viral ecology is still relatively new and many processes by which viruses influence hosts are still widely unknown. One problem is that there are few standardized techniques in virus ecology, making comparisons of data very difficult. To better understand the methodology, we first set out to make a video showing the process for the viral production assay using the “dilution and reoccurrence” method, which has become the standard to analyze production rates in aquatic ecosystems. Using this method, we also determined the production rates of viruses during a seasonal pelagic phytoplankton bloom during a cruise off the …


Functional Cloning And Characterization Of Antibiotic Resistance Genes From The Chicken Gut Microflora, Wei Zhou May 2011

Functional Cloning And Characterization Of Antibiotic Resistance Genes From The Chicken Gut Microflora, Wei Zhou

Masters Theses

A recent study using human fecal samples in conjunction with a culture-independent approach revealed immense diversity of antibiotic resistance (AR) genes in the human gut microflora. We hypothesize that food animal gut microflora also contain diverse and novel AR genes which could contribute to the emergence and transmission of AR in pathogens important in animal and human health. To test this, we examined AR reservoir in chicken gut microflora using a metagenomic, functional cloning method. Total genomic DNA was extracted from individual cecal contents of two free range chickens and two conventionally raised chickens. The DNAs were physically sheered into …