Food Science Commons^™

Insertional Inactivation Of Treponema Denticola Tap1 Results In A Nonmotile Mutant With Elongated Flagellar Hooks, Ronald J. Limberger, Linda L. Slivienski, Jacques Izard, William A. Samsonoff

Department of Food Science and Technology: Faculty Publications

The treponemal fla operon is comprised of numerous motility-related genes; however, the initial gene of this operon, tap1, has no known function. A recently developed system to generate specific mutants in Treponema denticola was utilized to determine if Tap1 was essential for motility. T. denticola tap1 and flanking DNA were identified, cloned, and sequenced, and a suicide plasmid that contained tap1 interrupted with an erythromycin resistance cassette (ermF and ermAM) was constructed. Because of potential polar effects from this cassette, a second plasmid that contained tap1 interrupted with a modified erythromycin resistance cassette that lacked the putative ermF transcription …

Membrane Topology Of The Colicin A Pore-Forming Domain Analyzed By Disulfide Bond Engineering, Denis Duche, Jacques Izard, Juan M. Gonzalez-Manas, Michael W. Parker, Marcel Crest, Daniel Baty

Department of Food Science and Technology: Faculty Publications

Four colicin A double-cysteine mutants possessing a disulfide bond in their pore-forming domain were constructed to study the translocation and the pore formation of colicin A. The disulfide bonds connected a-helices 1 and 2, 2 and 10, 3 and 9, or 3 and 10 of the poreforming domain. The disulfide bonds did not prevent the colicin A translocation through the Escherichia coli envelope. However, the mutated colicins were able to exert their in vivo channel activity only after reduction of their disulfide bonds. In vitro studies with brominated phospholipid vesicles and planar lipid bilayers revealed that the disulfide bond that …

Variations In Cream Tests, J F. Brennan

Journal of the Department of Agriculture, Western Australia, Series 4

DURING the year dairy farmers are often concerned about variations in the butterfat test of cream they supply to the butter factory.

Why do these tests vary? Is the variation the fault of the farmer or the butter factory?

Studies On Restaurant Sanitation And The Effect Of Sodium Azide On The Physiology Of Streptococcus Salivarius, Kenneth D. Rose

Open Access Master's Theses (through 2010)

Whether restaurant eating utensils serve as vectors in the transmission of respiratory and related diseases is still a matter for question, in spite of the overwhelming evidence in support of this contention.This is due to largely to the lack of epidemiological evidence, the tracing of an outbreak of a disease directly and unquestionably to contaminated eating utensils.The very nature of the vectors concerned obviates any possibility of obtaining this epidemiological evidence, since the contaminating agent exists as such only momentarily at the best. This research problem was undertaken with the hope that a technique designed to demonstrate the appearance of …