Microbiology Commons^™

Characterization Of The Omptin Protease, Ompt, In Escherichia Coli, Amanda Yates, Eun-Hae Kim, Helen Wing

Undergraduate Research Opportunities Program (UROP)

Omptins are outer membrane proteases found in gram negative bacteria that cause diseases in humans, such as pathogenic Escherichia coli, Shigella flexneri, Salmonella typhimurium, and Yersinia pestis. Bacterial species that express omptins cause diseases such as highly fatal plague and severe diarrhea and dysentery. The genes that encode these proteases are ompT, icsP, pgtE, and pla, respectively. These proteases are highly related in structure and share approximately 50% sequence identity. In S. flexneri, IcsP has been shown to cleave a key virulence determinant, IcsA (Egile et al., 1997). IcsA recruits host actin and allows for intracellular movement within host cells …

Denitrification In Great Basin Hot Springs, Austin Mcdonald, Brian P. Hedlund

Undergraduate Research Opportunities Program (UROP)

Hydrogen has been proposed to fuel primary production in the Aquificae dominated hot springs of Yellowstone National Park (Spear, et al. 2005), a finding the authors generalized to all hot springs. However, clone libraries derived from Great Basin springs contain few 16S ribosomal RNA (rRNA) gene sequences from Aquificae and many from unknown microorganisms. In the same springs, alternative electron donors rival the reducing power of hydrogen. This project will try to cultivate the uncharacterized microbes of two Great Basin springs and determine which electron donors they can use.

Nitrogen is key to life. In its reduced form, ammonia, it …

Old Acetogens, New Light, Steven L. Daniel, Harold L. Drake, Anita S. Gößner

Steven L. Daniel

Acetogens utilize the acetyl-CoA Wood-Ljungdahl pathway as a terminal electron-accepting, energy-conserving, CO2-fixing process. The decades of research to resolve the enzymology of this pathway (1) preceded studies demonstrating that acetogens not only harbor a novel CO2-fixing pathway, but are also ecologically important, and (2) overshadowed the novel microbiological discoveries of acetogens and acetogenesis. The first acetogen to be isolated, Clostridium aceticum, was reported by Klaas Tammo Wieringa in 1936, but was subsequently lost. The second acetogen to be isolated, Clostridium thermoaceticum, was isolated by Francis Ephraim Fontaine and co-workers in 1942. C. thermoaceticum became the most extensively studied acetogen and …

The Role Of Sos Boxes In Enteric Bacteriocin Regulation, Jan A.C. Vriezen Dr., Osnat Gillor Dr., Margaret A. Riley Dr.

Jan A.C. Vriezen Dr.

Bacteriocins are a large and functionally diverse family of toxins found in all major lineages of Bacteria. Colicins, those bacteriocins produced by Escherichia coli, serve as a model system for investigations of bacteriocin structure–function relationships, genetic organization, and their ecological role and evolutionary history. Colicin expression is often dependent on host regulatory pathways (such as the SOS system), is usually confined to times of stress, and results in death of the producing cells. This study investigates the role of the SOS system in mediating this unique form of toxin expression. A comparison of all the sequenced enteric bacteriocin promoters reveals …

Old Acetogens, New Light, Steven L. Daniel, Harold L. Drake, Anita S. Gößner

Faculty Research & Creative Activity

Acetogens utilize the acetyl-CoA Wood-Ljungdahl pathway as a terminal electron-accepting, energy-conserving, CO2-fixing process. The decades of research to resolve the enzymology of this pathway (1) preceded studies demonstrating that acetogens not only harbor a novel CO2-fixing pathway, but are also ecologically important, and (2) overshadowed the novel microbiological discoveries of acetogens and acetogenesis. The first acetogen to be isolated, Clostridium aceticum, was reported by Klaas Tammo Wieringa in 1936, but was subsequently lost. The second acetogen to be isolated, Clostridium thermoaceticum, was isolated by Francis Ephraim Fontaine and co-workers in 1942. C. thermoaceticum became the most extensively studied acetogen and …

Old Acetogens, New Light, Steven Daniel, Harold Drake, Anita Gößner

Faculty Research & Creative Activity

Acetogens utilize the acetyl-CoA Wood-Ljungdahl pathway as a terminal electron-accepting, energy-conserving, CO2-fixing process. The decades of research to resolve the enzymology of this pathway (1) preceded studies demonstrating that acetogens not only harbor a novel CO2-fixing pathway, but are also ecologically important, and (2) overshadowed the novel microbiological discoveries of acetogens and acetogenesis. The first acetogen to be isolated, Clostridium aceticum, was reported by Klaas Tammo Wieringa in 1936, but was subsequently lost. The second acetogen to be isolated, Clostridium thermoaceticum, was isolated by Francis Ephraim Fontaine and co-workers in 1942. C. thermoaceticum became the most extensively studied acetogen and …