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?
>>CJF
>>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
