Bacteriology Commons^™

Characterization Of Restriction-Modification Systems In Klebsiella Pneumoniae, Boontar Valinluck

Loma Linda University Electronic Theses, Dissertations & Projects

Two restriction-modification (R-M) systems KpnAI and KpnBl, found in Klebsiella pneumoniae strains M5a1 and GM236, respectively, have been studied and confirmed to he different from other R-M systems reported in K. pneumoniae. Mutant studies that the KpnAl and KpnBI systems may belong to either a type I or type III systems since approximately equal numbers of r^-m⁺ and r^-m^- mutants were obtained. However, a DNA hybridization study using representative type I and type III probes from E. coli and S. typhimurium failed to show homologies to either KpnAI or KpnBI. The restriction endonuclease …

A Modified Scheme For The Isolation And Enumeration Of Bacteria In Municipal Sewage Sludge, Kelly Ball

Masters Theses & Specialist Projects

Because of the potential health hazards associated with the use of sludge for agricultural purposes, Dudley et al (1980) published a scheme for the routine analysis of bacteria in municipal sewage sludge. In this study, the Dudley et al scheme (1980) was modified by updating some of the procedures. Aerobically digested sludge generated by the Bowling Green Wastewater Treatment Plant, Bowling Green, Kentucky, was analyzed using the modified scheme. Sludge samples were collected once every two months over a one-year period from October 1989 to August 1990.

Egg yolk-free tryptose sulfite cycloserine agar in conjunction with the revewrse CAMP test …

Genetics And Applications Of Nisin Production In Lactococcus Lactis Subsp. Lactis And Conjugal Exchange Of This Trait, Jeffery R. Broadbent

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Chapter I reviews current literature on gene transfer systems in lactic acid bacteria, how genetically altered microorganisms for food are presently regulated, and how nisin is used as a food preservative.

Chapter II investigates previous reports which linked genes for nisin biosynthesis and sucrose utilization (Nip⁺Suc⁺) to plasmid DNA in two well characterized L. lactis subsp. lactis strains. Plasmid curing studies, conjugations, and DNA-DNA hybridizations indicated that these genes were encoded by chromosomal loci in all Nip⁺Suc⁺ strains examined. Similar results were noted in nisin-sucrose transconjugants of L. lactis subsp. cremoris and S. …

The Expression And Regulation Of The Hsdk Genes Of Escherichia Coli K-12, Ainu Prakash

Loma Linda University Electronic Theses, Dissertations & Projects

The DNA restriction and modification of (R-M) genes in bacteria play a defensive role in the organism, offering protection to the host from invaders such as bacteriophages. The expression of these genes in E. coli K-12 has no previously been studied due to the complexity of EcoK R-M enzymes. The use of lacZ gene fusion techniques allowed studies of the expression of the hsdK genes for the first time. Operon fusions of Mu(lac) to the hsdK genes show that the two hsdK promoters, P_res and Pmod, are weak (50 Miller units) and that both operate …

The Expression And Regulation Of The Hsdk Genes Of Escherichia Coli K-12, Ainu Parkash

Loma Linda University Electronic Theses, Dissertations & Projects

The DNA restriction and modification (R-M) genes in bacteria play a defensive role in the organism, offering protection to the host from invaders such as bacteriophages. The expression of these genes in E. coli K-12 had not previously been studied due to the complexity of the EcoK R-M enzymes. The use of lacZ gene fusion techniques allowed studies of the expression of the hsdK genes for the first time. Operon fusions of Mu(/ac) to the hsdK genes show that the two hsdK promoters, p _res and p _mod, are weak (50 Miller units) and that …

Cyanonews (Vol. 8, No. 1, February 1992), Jeff Elhai

CyanoNews

CyanoNews was a newsletter that served the cyanobacteriological community from 1985 to 2003, with content provided by readers (sort of a blog before there were blogs). The newsletter reported new findings from the lab, summaries of recent meetings (often provided by graduate students and post-docs entering the field), positions sought or available, life transitions, a compendium of recent cyanobacteria-related articles, and other items of interest to those who study cyanobacteria.

Cyanonews (Vol. 8, No. 2, July 1992), Jeff Elhai

CyanoNews

CyanoNews was a newsletter that served the cyanobacteriological community from 1985 to 2003, with content provided by readers (sort of a blog before there were blogs). The newsletter reported new findings from the lab, summaries of recent meetings (often provided by graduate students and post-docs entering the field), positions sought or available, life transitions, a compendium of recent cyanobacteria-related articles, and other items of interest to those who study cyanobacteria.

The Morphology, Physiology, And Fine Structure Of A Toluene-Oxidizing Strain Of Pseudomonas Putida, Barry Clayton Anderson

Dissertations and Theses

The role of microorganisms in the degradation of xenobiotics in the environment is well established. Bacteria from the genus Pseudomonas are particularly well adapted to the degradation of hydrocarbons, aromatics, and numerous other natural and introduced substrates. We have isolated a strain of Pseudomonas putida, designated PC2P15, that uses toluene, phenol, benzene, and a number of other substrates as its sole sources of carbon and energy.