Transcript Citrate Utilization

Islamic University_Gaza
Medical Technology Department
Reham Sabri Hammad
2005\0076
Supervisor :
Dr. Abdelraouf A. Elmanama
2008\2007
Outlines
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Introduction.
Principle Of Citrate Test.
Significance Of Citrate Test.
Materials and Method.
Result.
Summary.
Introduction
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Tests for the ability of bacteria to convert
citrate (an intermediate of the Krebs
cycle) into oxaloacetate (another
intermediate of the Krebs cycle).
In this media, citrate is the only carbon
source available to the bacteria.
Principle Of Citrate Test
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To determine if an organism is capable of
utilizing citrate as sole carbon source for
metabolism with resulting alkalinity.
If organisms utilize citrate and ammonium
salts, the medium becomes more basic and the
bromthymol blue changes from green to blue
as a result of an increase in the pH of the
media.
If it can not use citrate then it will not grow.
Significance Of Citrate Test
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A differential cultural test to identify
genera within the bacterial family
Enterobacteriaceae that are able to utilize
sodium citrate as a sole source of carbon.
Materials
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1.
2.
3.
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Simmons Citrate agar
which contains :
sodium citrate (carbon
source) .
ammonium salts (nitrogen
source).
Bromthymol blue indicator.
Inoculating needle .
Method
1.
2.
Streak one
organism over the
surface of the agar
slant, then stab the
butt.
Incubate the tube
at37°C for 48 hours
.
Result
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Examine for growth
(+) .
Growth on the
medium is
accompanied by a rise
in pH to change the
medium from its
initial green color to
deep blue.
Result
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Some intestinal bacteria are (+)citrate as:
Klebsiella .
Citrobacter.
Enterbacter aerogenes .
while others is(-) citrate as: E. coli
Summary
Klebsiella
Enterbacter
aerogenes
Citrobacter
E. coli
(+)
(+)
(+)
(-)
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At last, I wish that you have enjoyed my
presentation.
Thank you, and have a nice day please.
My best wishes
References
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http://srv2.lycoming.edu/~diehl/321-f03/lecture2.htm
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http://whitewolf.newcastle.edu.au/techinfo/proc_bacto_biochem.ht
ml
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http://science.swu.edu/~wsinnamon/micrometabolism.htm
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http://web.fccj.edu/~lnorman/unknowns.htm?index=2
21\11