REU MICROBIOLOGY Students
Front Row (Left to Right): Amanda Yates, Washington State University, Alex Michaud, Coe College; Middle Row: Susie O’Neil, Central Michigan University, Paul Howse, UNLV; Top Row: MacLean Hall, Davidson College, Allison Faucher, Ohio Wesleyan University, Rachel Skinner, Transylvania University, Kathleen Bradley, University of Maine.
Kathleen Bradley, University of Maine
mentor, Eduardo Robleto, associate professor
The goal of our research is to determine whether the level of transcription of a gene is correlated with the level of mutation in that gene. One factor involved in the mutability of a transcribed gene is the ability of the single stranded DNA to form secondary stem loop structures (SLS), in the wake of the transcription bubble, that contain unpaired mutable bases. We are interested in correlating the levels of mutation with transcription in the thiF gene, which is predicted by bioinformatic analysis to be highly mutable. To achieve this goal, Kathleen will first construct a non-polar thiF genetic knockout using a chloramphenicol cassette. Then, she will test the phenotype of the ThiF- strain. She will also build an IPTG-inducible construct containing thiF with a stop codon in the loop of a putative SLS. This will be introduced into ThiF- Bacillus subtilis and assayed for the accumulation of Thy+ mutations under starvation conditions, in the presence and absence of IPTG.
Allison Faucher, Ohio Wesleyan University
mentor, Ronald Yasbin, professor
The goal of our research is to determine whether the level of transcription of a gene is correlated with the level of mutation in that gene. One factor involved in the mutability of a transcribed gene is the ability of the single stranded DNA to form secondary stem loop structures (SLS), in the wake of the transcription bubble, that contain unpaired mutable bases. We are interested in correlating the levels of mutation with transcription in the argF gene, which is predicted by bioinformatic analysis to be highly mutable. To achieve this goal, Allison will first construct a non-polar argF genetic knockout using a kanamycin cassette. Then, she will test the phenotype of the ArgF- strain. If a biochemical suppressor is present, she will disrupt the next possible genetic candidate. She will also build an IPTG-inducible construct containing argF with a stop codon in the loop of a putative SLS. This will be introduced into ArgF- Bacillus subtilis and assayed for the accumulation of mutations under starvation conditions, in the presence and absence of IPTG.
MacLean Hall, Davidson College
mentor, Ernesto Abel-Santos, associate professor
Bacillus anthracis and Bacillus cereus are both described as soil bacteria, but are almost exclusively found as spores within the soil. Soil is generally not a nutrient-rich environment and may lack the amino acids and nucleosides necessary for spore germination and vegetative reproduction. We aim to determine if soil alone can cause germination in these two species in order to produce vegetative cells that can reproduce. In addition, nematodes, decaying meat, maggots, and plant roots will be tested for their ability to cause germination in these species.
Paul Howse, UNLV
mentor, Dennis Bazylinski, associate professor
Magnetotactic bacteria contain magnetosomes; membrane-bounded iron crystal consisting of greigite (Fe3S4) and/or magnetite (Fe3O4). The magnetosomes cause the bacteria to align along the Earth’s geomagnetic field lines. A so-called magnetosome gene island (large cluster of magnetosome-related genes) is present in several characterized strains of magnetotactic bacteria. Strain FH-1 is an unusual freshwater magnetotictic bacterium with the morphology of a curved rod (vibrio) that biomineralized tooth-shaped crystals of magnetite. I propose to construct a genomic library for FH-1 in order to determine which of the magnetosomes genes are present, whether the gene island is present, and to determine if gene arrangement is conserved in this strain.
Alex Michaud, Coe College
mentor, Duane Moser, Desert Research Institute
This research is focused on developing a better understanding of the physiological and phylogenetic diversity as well as environmental abundance of bacteria of the genus: Shewanella in selected desert ecosystems. Prior research from this laboratory has revealed that these bacteria are very abundant in sulfur-and organic-rich aquatics habitats. We have selected a number of habitats for detailed investigation (cultivation, molecular ecology and relevant environmental chemistry) including the Tropicana Wash, spring in Death Valley, the lower Virgin River and possibly Big Soda Lame, NV.
Susan O’Neil, Cental Michigan University
mentor, Kumud Acharaya
Assessment of coliform bacteria from point and non point sources in Las Vegas Wash. Correlations between land use related runoffs, nutrients and organic matter loading and total coliform will be studied. Data will be collected for both daily low and high flow events. Sampling locations will cover all major land use types such as golf course, hotels, hospitals, residential areas etc. at both main Wash and the tributaries.
Rachel Skinner, Transylvania University
mentor, Brian Hedlund, associate professor
Photosynthesis does not occur above 73°C, so organisms living above this temperature must obtain useable carbon by some other mechanism. It is generally assumed that carbon is fixed by thermophiles through the process of chemolithoautotrophy; however, primary production has never been demonstrated to occur in hot springs >73°C. We have shown that two organisms, Thermocrinis and Pyrobaculum, make up more than 90% of the cells in an 80°C Great Basin hot spring, Great Boiling Spring. We hypothesize that these organisms fix carbon in the hot spring via the reverse tricarboxylic acid (rTCA) cycle. To test this hypothesis we will: (i) confirm that Thermocrinis and Pyrobaculum dominate in water from the spring; (ii) determine whether key genes for the rTCA cycle, citryl co-A lyase (ccl), 2-oxoglutarate:ferredoxin oxidoreductase (korA), pyruvate: ferredoxin oxidoreductase (porA), are present and expressed in the spring; and, (iii) measure rates of carbon fixation in the spring. Linkage of the genetic data with carbon fixation rate data may help to provide an image of carbon fixation and cycling in Great Basin hot springs.
Amanda Yates, Washington State University
mentor, Helen Wing, assistant professor
Determine whether Ompt expressed from new construct cleaves ICSA when expressed in shigella MBG34 (7csP-). I will be testing whether Ompt can protect shigella (and salmonella) from LL-37