Bacterial ID

Dr. R. O'Kennnedy ucecron at ucl.ac.uk
Wed Dec 3 13:06:16 EST 1997

Hi Maria,
A couple of points.

In my opinion Pseudomonas is a name given to G-  non-sporeforming bacteria, 
when their biochemical tests do not place them in any particular coherent 
grouping. Its a gross generalisation but  take a look at bergeys manual and 
the number of disparate biochemical tests that you need to do to identify them 
and you will see what i mean. In saying this Pseuds are well known for having 
plasmid encoded pathways for breaking down a range of chloro-phenolic and 
other recalcitrant organic compounds. So if this is what you bug does and is 
G- then you could possibly characterise it as a presumptive Pseud. 

Gram staining these are that will decide what API id kits you may need.  There 
are also a number of differential agars from oxoid and similar companies that 
will give you more of an idea what they are. I can't think of any specific 
ones for Pseuds but at least it will give you an idea of what it isn't. For 
exaple McConkey identifys PRESUMPTIVE coliforms. Presumptive because you need 
a range of other tests to confirm.

Alternatively, if you have a friendly molecular biologist who works on 16s RNA 
based identifications. By a process of PCR of the 16s RNA region, cloning and 
subsequent DNA sequencing, the bugs can be placed in particular phylogenetic 
groups of related organisms. 

Alternatively #2 There is a method called pyrolysis mass spectormetry which 
can rapidly characterise bug by their pyrolysed fatty acid profiles. Bugs are 
then identified by comparison to neural network of info on other bugs. Have a 
look at the www page below for more info

Hope this helps


In article <89ED47C52 at server1.rtc-athlone.ie>, mdavoren at SERVER1.RTC-ATHLONE.IE 
("MDAVOREN") wrote:
>Hi All,
>I am currently working with microbial cultures that are cabable of 
>breaking down a certain chemical I work with. I know that I have a 
>mixed culture as plating out has revealed several different types of 

Dr. R O'Kennedy
The Advanced Centre for Biochemical Engineering,
Department of Chemical and Biochemical Engineering,
University College London,
Torrington Place,
London WC1E 7JE
e-mail r.o'kennedy at ucl.ac.uk
phn 0171 419 3247

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