Microbial Biosynthesis of fluorescein?

CASUser casuser at unt.edu
Thu Apr 4 23:35:11 EST 2002

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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