Results

    The first phase of this project was not successful.  The group has concluded that these efforts were not successful due to numerous factors.  Foremost, it is believed that the vacuum sealing of the salted herring prevented any bacteria from surviving on the sample.  The elevated temperature of the incubation was probably also to blame as well as the dehydration of the media and crystalization of its salts.

    The second phase of experimentation was more fruitful.  The goal of the project was to isolate a salt tolerant organism from a marine environment.  The group was successful because bacterial growth was observed on the plates and tests were consistent with the data given in Bergey's Manual.  Here are the results of the tests that were performed:
 


Test
Observations and Test Results
Gram Stain
Pink bacillus; Gram negative
Oxidase Test
Blue; produces oxidase enzyme, oxygen tolerant
Catalase Test
Bubbles; produces catalase enzyme, oxygen tolerant
MacConkey's Plate
No Growth; inconclusive
T-soy Plate
Dull orange colonies; same as seawater plates
Motility Stab
Motile
O/F Test without Oil
Yellow; may be capable of oxidation
O/F Test with Oil
Yellow; capable of fermentation, may be facultative anaerobe

This is a picture of the bacteria growing on a T-soy plate.  Although the bright background makes the colonies appear dark, they are actually a light orange.

This is a picture of a Gram stain from the above plate.  Although the picture is slightly blurred, the bacteria are clearly pink rods (Gram negative).


 


    This organism was identified through several tests performed by the group.  The bacteria was able to grow in a salt water media as well as an environment where salt was absent (T-soy plates).  This indicates that the organism is salt tolerant.  Very few microbes are able to grow in high salt concentrations (such as 3% in the seawater medium), therefore the organism is more easily selected for and consequently identified.  The organism is Gram negative with rod-shaped cell morphology.  The color of the colonies on the T-soy plates (dull orange) also proved helpful during identification.  The metabolism of the organism was also used to identify it.  The bacteria is capable of fermentation and can also tolerate the presence of oxygen, therefore the organism may be a facultative anaerobe.  It is motile in some stages of development which is another characteristic that enabled the group to successfully identify it.

    This data has lead the group to believe that the bacteria is a member of the genus Vibrio and may be the species V. fischeri.

 
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