Microbial Biosynthesis of fluorescein?

Tom McCloud mccloud-tom at worldnet.att.net
Wed Apr 10 20:25:06 EST 2002

     Thanks for the information.  I am aware of pyoverdin, but never
heard fluorescin used as a synonym.   It had occurred to me that the
use of the word fluorescin in the literature going back before 1948
could mean some other substance,  not the specific molecule I
associate with it.  In that literature I found no
extraction/isolation/identification information, nor structure for the
compound referred to as fluorescin.  I'm also aware of the existence
of other peptide-based fluorescent pigments from Pseudomonas.   
     But just to settle my question once and for all, I'm going to do
a little hplc analysis on about 20 different Pseudomonas extracts.
That will tell me for sure whether there is pyoverdin, fluorescin or
none of the above.    Don't expect a quick post on results, but it'll
come.      Tom McCloud     SAIC-Frederick  

On Thu, 04 Apr 2002 22:35:11 -0600, CASUser <casuser at unt.edu> wrote:

>Fluorescein is an older name for the iron-scavenging pigment pyoverdin
>(aka pseudobactin, aka pyoverdine, aka a few other archaic names), which
>is a yellow-green pigment.  Pyocyanin is another pigment produced by
>Pseudomonas that is more blue-green.  The Pseudomonas identification
>plates P agar (pyocyanin) and F agar (fluorescein=pyoverdin) are named
>after the pigments produced primarily when grown on these media. 
>Pseudomonads are differentiated based upon the reaction on these media,
>among about a billion other characteristics.
>However, to answer your question: the chemical compound and the pigment
>have nothing in common besides the name and the color (yellow-green with
>UV fluorescence).  Pyoverdin is a complex molecule composed of a
>chromophore attached to a long peptide chain.  It would be pretty hard
>to synthesize this without the aid of the bacterium!  I wouldn't doubt
>it if the chemical was named after the pigment coloration, though. 
>Wonder what the history of that is?
>Bob wrote:
>> On Thu, 04 Apr 2002 03:10:36 GMT, Tom McCloud
>> <mccloud-tom at worldnet.att.net> wrote:
>> >       Fluorescein has been one of the most commonly used dyes in
>> >biology for many years, and other fluoresceins and galleins are used
>> >for a great many purposes from food colorings to textile dyes.  I had
>> >always assumed that the fluoresceins were synthetic substances, until
>> >recently, when I stumbled across a couple very old references to
>> >production of fluorescein by Pseudomonas aeruginosa and P. pyocyaneus,
>> >( for example - King, et.al., Canadian J. Research  26C, 514, 1948).
>> Tom,
>> I would be somewhat surprised if Ps made the specific chemical
>> fluorescein; perhaps there is some terminology issue in these older
>> papers.
>> Some groups of Ps do make fluorescent pigments. In fact, those species
>> are known as the fluorescent pseudomonads. The most famous of the
>> pigments is pyocyanin, which is not closely related to fluorescein.
>> I would suggest you include the word Pseudomonas in any search, and
>> maybe search out more generally on Ps pigments. Using pyocyanin as a
>> search term may or may not help. A review article on Ps pigments,
>> perhaps found with the help of the term pyocyanin, could be very
>> useful.
>> You might also try Medline; they do index much of the general bio
>> literature.
>> bob
>> posted/emailed
>> >       My next question was about the biosynthetic pathway for
>> >fluorescein, but a SciFinder search failed to turn up anything
>> >specific.   Actually, it turned up hundreds of hits on 'fluorescein',
>> >as in used for staining and thousands on biosynthesis,  but nothing
>> >linking those two.   I read down through about a hundred titles listed
>> >as 'biosynthesis and fluorescein close together', but saw nothing of
>> >interest.
>> >       And I was also interested in learning whether there were other
>> >similar compounds, either fluoresceins or galleins, also produced by
>> >various microbes.
>> >       I've got access to the literature, but need some help in
>> >getting into it, specifically on this topic.   Suggestions of authors
>> >I should search on?  Other tactics for finding articles on microbial
>> >biosynthesis of fluorescein?     Thanks for the help.
>> >       Tom McCloud
>> >       SAIC-Frederick

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