frogfot
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Yeast in organic synthesis
There was some thread that gave an adress to an e-book about this, but I couldn't download it..
Anyway, do anyone have some interesting and simple reactions that could be carried out with help of yeast?
As I understand, yeast can reduce carbonyl and nitro groups (not sure on second one).
In org chem we did reduction of.. I think it was acetoacetate. That was a tedious lab since separation was made by a solvent, alot of solvent 
I wanna test some similar reaction with more widely available precursor(s) where product is preferrably removed by destillation (but it doesn't
matter really). Any example would be nice to hear.. maby someone have experience in such synthesises.
Btw, www.orgsyn.org have some references to reactions with yeast but precursors seems to be a bit complex..
Oh, and ethanole brewing is already tested 
..maby reducing mesityl oxide..
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Marvin
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I'm interested in what yeast can be made to do, but so far everything Ive read follows the same pattern. Enzymes do very specific jobs usually
only on one target molecule, so the bacteria that turn wine into vinigar for example, we wouldnt expect to work with methyl alcohol unless it had
specific additional enzymes for the job.
In the same way all the products I know about are part of an existing cycle.
Glycerol, Butyric acid, Lactic acid, Ethanol, Succinic acid etc are all normally present, and the key is just to cripple part of the cycle so one
chemical accumulates in high yeild.
If theres any information that yeast will reduce carboyl functions generally, or nitro groups generally, Id be interested to see it, but so far
everything Ive seen fits the same enzyme pattern of one enzyme for one specific reaction.
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frogfot
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Oh, sorry I'm a bit late.. but today school ended 
I just made an assumption that it reduces carbonyl groups... In this file:
http://bio.bio.unibuc.ro/biochemistry/Enzimology/Vol6No4-200...
they mentioned that the more nonsymmetric ketones are the better in enantioselectivity, that is, with one large, and one small side like Ph-CO-Me
it'll produce more L-product. Thats about all info I could google..
Heres some info on nitro group reduction:
http://www.ch.ic.ac.uk/ectoc/papers/04/4-Oxidoreductases.htm...
[Edited on 3-6-2004 by frogfot]
[Edited on 3-6-2004 by frogfot]
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Organikum
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There is a file on the ftp called "bakers yeast in organic synthesis", there are several books on the ftp covering this - I am not sure what
you need more.
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chemoleo
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Frogfot, interesting sites 
Principally, most, if not all reactions can be theoretically done with enzymes. EXcept maybe some highly endothermic ones. I dont necessarily mean
natural enzymes, but rather designed ones.
Anyway- regarding the reactions Marvin is speaking of - there are some enzymes that perform a general reaction, such as nitro group reductions, or
there are enzymes that are specific to a particular reaction with a particular compound. To use normal bakers yeast to use one of these enzymes
specifically is probably rather inefficient - except for the traditional ones (--> ethanol production).
Instead, what is done today (AND employed industrially) is to over-express those enzymes that are necessary for a given reaction, thereby enhancing
reaction rates - or, more commonly, to overexpress it, and toisolate the enzymes, and perform the reactions in vitro (in reaction vessels, aka in the
test tube).
This is done, for instance, for the production of many antibiotics (particularly chiral ones).
Here the necessary enzymes are covalently linked to beads (often glass, or plastics), and incubated with the antibiotic precursor. Once the reaction
is complete, the product is flushed through, and the enzyme beads are recovered. A great technique, with very little chemical waste and recyclable
catalyst! Unfortunately, not particularly easy to do for the home chemist 
PS shouldnt this go into the biochem section?
[Edited on 4-6-2004 by chemoleo]
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
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frogfot
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Orgy, on what ftp? Just got access to axehandles ftp, there seems to be quite alot on enzymes, but I can't find that book (title sounds very
interesting).
The problem is, I dunno much biochemistry to properly affect the metabolism (citric acid cycle and so on) of yeast.. to accumulate specific involved
compounds.
There is some info on sucrose to acetone at high pH and/or addition of sodium sulfide. Though I dont have the specifics..
Mmm.. industrial biocatalysts.. how about a column of yeast for continious brew making.. in school we made small yeast balls, I don't remember
how but there was some binder added to yeast, and this mass was dropped into stirred water (the drops remained undissolved), and the binder solidifyed
making uniform balls. That would be tedious brewing..
Oh, soz, I couldn't decide where to put this thread.. title kinda belongs in both sections..
[Edited on 4-6-2004 by frogfot]
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Organikum
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look harder.
bakers_yeast_org_synth.pdf
is the exact name.
Also of interest:
biocatalysis_book.rar
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carbocation
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have a look on the hive in the serious chemistry forum. Theres a superb thread on biosynthesis using yeast to produce some interesting compounds. I
wont supply the link as I think you have to be a registered member to view the Serious chem forum and novel discourse forums.
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