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?
>> 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).
>> I would be somewhat surprised if Ps made the specific chemical
> fluorescein; perhaps there is some terminology issue in these older
>> 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
>> You might also try Medline; they do index much of the general bio
>> > 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
> > 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