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Antagonistic properties of aquatic myxobacteria and pseudomonads

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Field Value
Title Antagonistic properties of aquatic myxobacteria and pseudomonads
Names Burnison, Bryan Kent (creator)
Pacha, R. E. (advisor)
Date Issued 1968-05-11 (iso8601)
Note Graduation date: 1968
Abstract Certain species of the orders Myxobacterales and Pseudo-monadales are well-known antagonists. Pseudomonas fluorescens
and Pseudomonas putida have been reported to produce bacteriostatic
and bactericidal substances. Among the myxobacteria there
are various species which are known for their ability to produce
lytic enzymes and antibiotics. Organisms from both of these groups
of bacteria are known to occur in the aquatic habitat.
During studies on the microbial flora of experimental streams,
it was found, at times, that myxobacteria represented a significant
proportion of the bacterial population. This suggested that either
the environmental conditions favored the growth of these organisms
specifically or that inhibiting substances were being produced by
these bacteria which prevented the growth of other bacterial species.
A number of non-fruiting,fresh-water myxobacterial isolates were found to produce antibiotic substances. This finding was of interest
since the production of these substances by non-fruiting myxobacteria
has not been previously reported. The antibiotic material
had a fairly broad spectrum since it was capable of inhibiting the
growth of a variety of different bacterial species. The inhibitory
substance produced by one of the isolates was partially purified by
ethanol precipitation. This antibiotic was found to be water soluble
and heat stable.
An association between P. fluorescens and certain aquatic
myxobacterial isolates also was suggested from the bacteriological
surveys of the experimental streams. One stream had a predominance
of pseudomonads and very scant myxobacterial growth in
comparison with the other five streams studied. It was therefore
of interest to study the interrelationship between these two groups
of bacteria. Mixed culture studies showed that myxobacterial
growth was markedly inhibited by the presence of certain pseudo-monads. A crude toxic preparation was obtained from one of the
pseudomonad isolates. This material was found to exert a bacteriostatic
effect on certain myxobacteria. The substance was also inhibitory
for Sarcina lutea and Bacillus cereus. The crude toxin was
found to be heat stable, water soluble and dialysable.
Genre Thesis/Dissertation
Topic Pseudomonas
Identifier http://hdl.handle.net/1957/47068

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