Author Topic: Biosynth: Homebrewing Ephedrine  (Read 13363 times)

0 Members and 1 Guest are viewing this topic.


  • Guest
Air sterilization
« Reply #120 on: May 31, 2004, 09:17:00 AM »
A charcoal filter alone will not sterilize the air in itself, as bacteria will breed quite easily on the charcoal surface. This is often a desired effect, such as in aquaculture, as the aerobic bacteria that colonizes on the charcoal will break down ammonia produced by fish waste into nitrite and ultimately into nitrate. The charcoal will only serve to absorb contaminates out of the air and will allow fungal spores or bacteria to pass easily through.

A HEPA filter or micron filter will catch most spores but not necessarily all of them, and not bacteria.

A UVC Sterilizer Lamp is a common option, available from hydroponic shops and water purification places. These bulbs sterilize the air or water that pass by them and will easily kill any bacteria or fungal spore. They do however, have the unfortunate effect of producing ozone, which may find it's way into the reactor and kill the substrate. If a charcoal filter is used after the UVC lamp, the ozone will be absorbed by the charcoal and %100 sterile air will pass through.

Another simpler option that I read from a brewing manual was having an air lock filled with bleach or alcohol. When suction is applied, air will be drawn through the liquid from one side of the air lock to the other, which will result in "sterile" air.

Just remember that there is a very distinct difference between contaminated air and sterile air, as contaminated air is often sterile and relatively clean air can still have microbes present. Charcoal only serves to decontaminate air and only certain contaminates at that.


  • Guest
« Reply #121 on: June 02, 2004, 08:21:00 PM »
Well, the air temperature could be increased to the point that all or most bacteria would die. Then let cool for the reaction.

what about these ultrafilters (0.1µ) used for filtering pyrogenes and viruses?

What about buying a sterilizing filtering device/machine, used in industrial production, into which you install a membrane filter (cellulose nitrate).

These should not be expensive either.


  • Guest
air sterilisation
« Reply #122 on: June 04, 2004, 08:51:00 PM »

How should air bee sterilized before introduction in to the bioreactor?

Use HEPA filters or bubble the air through EtOH. NOT denaturated alcohol of course.


  • Guest
hydrogen acceptor
« Reply #123 on: July 11, 2004, 05:13:00 PM »
It seems like acetaldehyde can be substituted by acetone in the biotransformation of benzaldehyde to phenylacetylcarbinol mediated by bakers yeast. This refers to the method using molasses, nutrient salts and thiamine (or whey, or brewers wort) and plain BAKERs YEAST (saccharomyces cerevesiae).

Acetaldehyde was applied as a hydrogen-acceptor in this reaction, its role was to scavenge hydrogen and to get converted to ethylalcohol. Every acetaldehyde converted to the alcohol says one benzaldehyde saved from being converted to benzylalcohol. (the main side product in this reaction).
It is long known that acetone is converted to isopropylalcohol by fermenting yeast (even mono and di-chloroacetone btw. - at least partially). The question if it will substitute acetaldehyde was not answered. Probably because it was never asked.  ;D

Now it was asked and answered all in one.

ORG  :)


  • Guest
If acetone won't work (and your theory is...
« Reply #124 on: July 11, 2004, 05:23:00 PM »
If acetone won't work (and your theory is correct), then maybe other, easier to handle aldehydes could be added?


  • Guest
It´s not my theory
« Reply #125 on: July 12, 2004, 06:53:00 PM »
Acetaldehyde serving as hydrogen-acceptor is told in several articles and for example in the

Patent DD51651

(some of the examples in the patent are proven to be working well btw.).
Acetone works, as with acetaldehyde the amount which can be added is limited due to its toxity to the yeast (benzaldehyde the same). Formaldehyde cannot be used for this reason - its plain too toxic. Acetone has the advantage not to kill the yeast (except in VERY high concentrations but only to suppress fermentation. After some time the yeast will recover as the processes which transform the acetone to the alcohol (which is also toxic but much less) and the benzaldehyde to the l-PAC are independent from fermentation. The fermentation replentishes enzymes which are used up though.

A lower toxity substitute would be preferred of course. Any suggestions?


  • Guest
Pyruvic acid maybe?
« Reply #126 on: July 12, 2004, 11:20:00 PM »
Pyruvic acid maybe?
I'm not in the mood to go trough the whole thread, but aren't pyruvates used in some patents? Pyruvic acid is surely less toxic than acetone and acetaldehyde, besides being quite OTC and yielding only the edible lactic acid as a side product. Another less toxic ketone should be 2-butanone, but it is less soluble in water.


  • Guest
pyruvic acid
« Reply #127 on: July 12, 2004, 11:37:00 PM »
Yes, one of the patents I liked used pyruvic acid and the yeast saccharomycae cervisiae (sp?).  Pyruvate is very OTC, too.


  • Guest
No, Nicodem...
« Reply #128 on: July 13, 2004, 03:47:00 AM »

As you can see, the pyruvic acid is the reactand which produces l-PAC with benzaldehyde. If the pyruvic acid is added directly or if it is produced by the yeast from molasses or glucose doesnt make so much difference. If pyruvic acid or a salt of it is added directly non-fermenting conditions are used, if molasses or another source of fermentable sugars is used activly fermenting conditions have to be used. But this nothing to do at all with the question for a hydrogen acceptor, which plays solely the role to act as additional prey for the also yeast mediated aldehyde to alcohol reaction.
This for acetaldehyde is usually added which ends up as ethylalcohol.
Also ethylalcohol can be added to the biosynthesis to suppress ALL alcohol producing processes mediated by the yeast as far as possible. Yeast reduces them when a certain level of alcohol is reached in an attempt not to commit suicide.

I hope I could clear this up.