Masters Theses

Keywords and Phrases

Bradyrhizobium japonicum; Quorum sensing


"Bacterium-bacterium signaling, termed quorum sensing is a relatively well described phenomenon in bacteria. The best characterized quorum-sensing mechanism is found in Gram-negative organisms and incorporates the use of acylated homoserine lactones (AHLs) as signal molecules. Until this study, Bradyrhizobium japonicum, the soybean symbiont, was absent from the list of known autoinducer producing organisms.

The data presented here describe the discovery of autoinducer production in several strains of B. japonicum. Further characterization of the autoinducer(s) was needed to determine the extent of autoinducer production toward the goal of determining the role of autoinducer(s) in the symbiosis with soybeans. Through the characterization process three main aspects of the autoinducer(s) were analyzed: identification, time of production, and activity/function. From this study, it was determined that the extracted autoinducers share similar characteristics with other known AHLs and that multiple autoinducers are produced by B. japonicum. It was also determined that autoinducer production was greatest at mid-log phase growth of cell cultures. Lastly, it was determined that autoinducer presence showed no significant inhibitory function to growth in both autoinducer and non-autoinducer producing strains. Most importantly, the light shed on these three important aspects of the autoinducer(s) produced by B. japonicum, furthered our understanding of quorum sensing and its role in the symbiosis between B. japonicum and soybean."--Abstract, page iii.


David Westenberg

Committee Member(s)

Ron Frank
Yinfa Ma


Biological Sciences

Degree Name

M.S. in Applied and Environmental Biology


University of Missouri--Rolla

Publication Date

Fall 2004


ix, 51 pages

Note about bibliography

Includes bibliographical references (pages 46-50)


© 2004 Jason Charles Elrod, All rights reserved.

Document Type

Thesis - Restricted Access

File Type




Subject Headings

Rhizobium japonicum
Thin layer chromatography
Soybean -- Microbiology

Thesis Number

T 8695

Print OCLC #


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