Abstract

A mutant of Salmonella potsdam SP2 which had been grown in mixed culture with either of three F+ strains of Escherichia coli was unable to serve as a donor of chromosomal genes when mixed with another mutant of S. potsdam. Therefore, there was no evidence of F transfer in these crosses.

To promote the formation of conjugal pairs, the filter mating technique of Matney and Achenbach was used. With this method, no recombinants were detected when six different Hfr strains of E. coli were mated with various mutants of SP2. Hfr K1 of Salmonella typhimurium transmitted loci for the biosynthesis of methionine, histidine and leucine to a mutant of S. potsdam at a frequency up to 7 X10-3. However, no genetic transfer was detected when a recombinant from this cross was However, mated with another mutant of S. potsdam.

An F-lac+ strain of E. coli was capable of transmitting its lac+ gene to a mutant of SP2 at a frequency of 10-7. Transfer was increased to as high as 26% when the S. potsdam recipient culture was first treated with the mutagen, nitrosoguanidine. The lac+ gene of S. potsdam obtained from E. coli in these crosses was eliminated from the cells by growth in the presence of acridine orange. These lac+ recombinants of S. postdam were able to transmit the lac+ gene to another mutant of SP2 at a high frequency after the recipient cells had been treated with nitrosoguanidine.

Thus, S. potsdam SP2 could serve as a high frequency recipient of chromosomal genes from an S. typimurium Htr and F-lac+ from E. coli. No donor ability was detected in the S. typhimurium - S. potsdam hybrids; the F-lac+ episome from E. coli was transmitted between mutants of S. potsdam at a high frequency.

LLU Discipline

Microbiology

Department

Microbiology

School

Graduate School

First Advisor

Leonard R. Bullas

Second Advisor

Robert L. Nutter

Third Advisor

Ivan R. Neilsen

Degree Name

Master of Science (MS)

Degree Level

M.S.

Year Degree Awarded

1968

Date (Title Page)

6-1968

Language

English

Library of Congress/MESH Subject Headings

Salmonella

Type

Thesis

Page Count

v; 43

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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