Author Topic: Biosynth: Homebrewing Ephedrine  (Read 53141 times)

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  • Guest
The most effective way to L-PAC
« Reply #60 on: January 24, 2003, 09:44:00 AM »

The most effective way to do this biotransformation is:
benzaldehyde + acetaldehyde + molasses + brewers wort + some salts
benzaldehyde from toluene and/or benzylalcohol
acetaldehyde from ethylalcohol
Yields up to 70% on benzaldehyde. But who minds if less, as the benzaldehyde not converted to L-PAC gets converted to benzylalcohol which can be oxidized to benzaldehyde again quite easily. Without acetaldehyde yields are cut by half.
Java has linked to the post with the writeup, if some is interested in the details. To the writeup is to add that it is not necessary to distill the L-PAC as written, but the extract from the fermentation broth can be reductive animated as is. No strong vacuum pump necessary! Tested with Al/Hg reductive alkylation.

The method is unbeaten by now (except by pure separated enzymes, >90% but extreme expensive).

Great work Placebo! Quite comprehensive, real good work.


  • Guest
Re: I will be happy if I would get the L-PAC...
« Reply #61 on: January 24, 2003, 12:26:00 PM »

I will be happy if I would get the L-PAC properties

Tell me about it, I looked for about 12 hours today!

Org, check if there is anything useful on that last link and save it, otherwise it will disappear from the cache and the .pdf has to be paid for.


  • Guest
What Rhodium sent me
« Reply #62 on: January 24, 2003, 03:24:00 PM »

(R)-(+)-Mandelic acid + MeLi -> (+)-acetylphenylmethanol (45%)
   Tetrahedron Lett.; EN; 28; 50; 1987; 6313-6316.

(R)-(-)-1-hydroxy-1-phenyl-2-propanone, bp 72-74°C/0.2mmHg
   Collect.Czech.Chem.Commun.; EN; 55; 8; 1990; 2046-2051.
   Collect.Czech.Chem.Commun.; EN; 55; 11; 1990; 2685-2691.

1-phenyl-propane-1,2-dione -H2/Pt/Al2O3-> (S)-(+)-1-hydroxy-1-phenyl-2-propanone
   J.Catal.; EN; 204; 2; 2001; 281 - 291.

   Justus Liebigs Ann. Chem.; 526; 1936; 143, 170.
   Biochem.Z.; 127; 1922; 338.
   Chem.Zentralbl.; GE; 111; II; 1940; 1860.

(RS)-1-Hydroxy-1-phenyl-aceton (racemic), mp 9.5-11°C (ether, pentane)
   Can.J.Chem.; EN; 68; 11; 1990; 2060-2069.

Boiling Point   mmHg   Reference
66°C      0.2    1
236-238°C   760    2
143-145°C   31    3
130-132°C   20    4
124°C      14    2
129-131°C   14    5
129-130°C   13   6
106-108°C   7    7-8
104-106°C   6   9

Ref. 1    J.Amer.Chem.Soc.; 73; 1951; 4284.
Ref. 2    Justus Liebigs Ann. Chem.; 526; 1936; 143, 170.
Ref. 3    Biochem.Z.; 127; 1922; 338.
Ref. 4    Bull.Soc.Chim.Fr.; <4> 33; 1923; 770, 771;
    C.R.Hebd.Seances Acad.Sci.; 176; 1923; 313.
Ref. 5    Zh.Obshch.Khim.; 27; 1957; 1622,1625;engl.Ausg.S.1694,1697.
Ref. 6    Mem.Inst.Sci.Ind.Res.Osaka Univ.; 6; 1948; 96, 98.
Ref. 7    Yakugaku Zasshi; 77; 1957; 851,853; Chem.Abstr.; 1958; 1949.
Ref. 8    Yakugaku Zasshi; 76; 1956; 1250, 1253; Chem.Abstr.; 1957; 4309.
Ref. 9    Zh.Obshch.Khim.; 21; 1951; 183,185;engl.Ausg.S.199,201.

Boiling Point    mmHg   Ref:
65-67°C      0.4   1
100-102°C   0.01   2
123-124°C   12   3
124-125°C   12   4
118-119°C   8   5-6

Ref. 1    J.Med.Chem.; EN; 7; 1964; 427-433.
Ref. 2    Collect.Czech.Chem.Commun.; EN; 37; 1972; 3897-3901.
Ref. 3    Chem.Zvesti; 12; 1958; 687; Chem.Abstr.; 1959; 11289.
Ref. 4    Biochem.Z.; 127; 1922; 133.
Ref. 5    Chemia anal.; 3; 1958; 573; Chem.Abstr.; 1959; 13841.
Ref. 6    Chem.Zvesti; 12; 1958; 17,19; Chem.Abstr.; 1958; 10768.

Thats on the properties. Plus what lugh posted.
some tidbits out of patents and articles:
- L-PAC racemizes fast under basic conditions and higher temperatures. So keeping fermentation temperatures low and ph as acidic as possible (4,3 - 4,7, whereby 4,3 is only possible with yeast harvested in acidic enviroment). On the other side this offers a perfect way to tune your gear after your personal preferences.  :)
- Useful for extraction of L-PAC from the fermentation broth are most nonpolar solvents as: (diethyl-)ether, petrolether, DCM and ethyl acetate. A continous extraction is favorable at low temperatures one can also boil away some of the water as long not dealing with serious amounts to synthesize. Salting out helps a lot.
- The yeast may be washed and reused after the fermentation one or two times, then undergo autolysis to gain yeast extract useful as feed in following fermentations. The extract reduces the needed amounts of salts and brewers wort.
- The yeast to use is not critical. Bakers yeast from the supermarket. Harvesting this yeast under acidic conditions aka adding up to 3% sulfuric acid hardens the yeast and makes a ph as low as 4,3. possible (if not hardened ph 4,7 to 5,2).

what brings up this sudden interest again I wonder?
perhaps the wintertime

Placebo: 12 hours? I tried it 2 weeks and didn´t get anything some time ago...


  • Guest
Re: biosynth-transformation
« Reply #63 on: February 03, 2003, 11:13:00 PM »
I thought I bring in this piece of the puzzle to this thread since it seems to fit in in the quest  to a source of starting material......the elusive Ephedrine Hcl,

Organikum fills in some more pieces to the puzzle,

Post 400469

(Organikum: "L-PAC reductive alkylation", Novel Discourse)


  • Guest
Toluenes to aldehydes by peroxidase
« Reply #64 on: February 19, 2003, 06:18:00 PM »
Benzylic biooxidation of various toluenes to aldehydes by peroxidase

Russ, Rainer; Zelinski, Thomas; Anke, Timm
Tetrahedron Lett. 2002, 43: 5 791 – 794

A catalytic method is described for the oxidation of toluene and substituted derivatives to the corresponding benzaldehydes by hydrogen peroxide, using peroxidase. In most cases the respective benzoic acid was produced as a byproduct. The reaction proceeds under mild conditions in an aqueous medium.


  • Guest
Benzylic biooxidation of various toluenes to aldeh
« Reply #65 on: April 20, 2003, 01:34:00 AM »
Substituted benzaldehydes are often used as feedstock in industrial chemistry. The selective oxidation of aromatic methyl groups to the respective aldehyde is, however, difficult.[1] The chemical oxidation of the methyl group commonly proceeds directly to the carboxylic acid. We therefore chose to investigate enzymatic methods, because enzymes can be chemoselective. We started with the laccase/2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) system of Potthast et al. [2] However, with toluene and laccase from different fungi, such as Bjerkandera adusta, Coriolus sp., Phellinus sp., and Pleurotus ostreatus, we found no transformation at all, which is in accordance with the findings of Fritz-Langhals and Kunath.[3] Subsequently, we tried several peroxidases with hydrogen peroxide as the oxidant. Using lignin peroxidase from Phanerochaete chrysosporium[4] or Coprinus cinereus,[5] we found no transformation of toluene. Chloroperoxidase from Caldariomyces fumago gave a slight transformation to benzyl alcohol and benzaldehyde, as reported earlier.[6 and 7] Finally, peroxidases isolated from a Coprinus species of our strain collection were able to catalyze the transformation of toluene to benzaldehyde and, only to a minor extent, benzoic acid (Table 1).

The transformation of 21 different substituted methyl aromatics by hydrogen peroxide and Coprinus peroxidase was tested. Only three of the compounds tested, p-cymene (4-isopropyl-toluene), m-cresol, and p-cresol, were not at all transformed into the corresponding benzaldehydes. All other 18 compounds were transformed into the respective benzaldehydes whereby the efficiency of the reaction varied (Table 1). Suitable substituents comprised methyl, halogen, methoxy, and nitro groups. It seems that the position of the substituent was more important than its composition. Ortho or para positions of the substituent to the methyl group were preferred against meta, except for the nitrotoluenes. o-Nitrobenzaldehyde was obtained in a low yield, whereas m-nitrobenzaldehyde was formed with yields comparable to the p-isomer. In the case of o-nitrotoluene, an interaction of the intermediate methyl cation radical with the nitro group perhaps prevented the formation of the aldehyde. o-Nitrotoluene was the only substrate that produced the alcohol derivative. The cresols were found not suitable for catalytic conversion by Coprinus peroxidase and hydrogen peroxide, probably due to polymerization reactions as described for lignin peroxidase.[4] The preparation with o-cresol immediately turned yellow after addition of the enzyme. A weaker discoloration to yellow was observed for m- and p-cresol, as well as toluene, 3-chloro-, 4-methoxy-, and 4-fluorotoluene. p-Cymene was transformed into two compounds that were not identified. A molecular mass of 132 and 136 inferred that none of the compounds was either an aldehyde- or carboxyl-derivative of p-cymene.

In summary, the method presented here used Coprinus peroxidase and hydrogen peroxide to oxidize a variety of toluene derivatives to their corresponding aldehydes. Further studies are underway to characterize the enzyme responsible, as well as improving the reaction conditions to provide better yields.

1. W.J. Mijs and C.R.H.I. de Jonge. Organic syntheses by oxidation with metal compounds, Plenum, London (1986).

2. A. Potthast, T. Rosenau, C.-L. Chen and J.S. Gratzl. J. Org. Chem. 60 (1995), pp. 4320–4621.

3. E. Fritz-Langhals and B. Kunath. Tetrahedron Lett. 39 (1998), pp. 5955–5956. Abstract | PDF (107 K)

4. M. Tien and T.K. Kirk. Proc. Natl. Acad. Sci. USA 81 (1984), pp. 2280–2284.

5. F. van Rantwijk and R.A. Sheldon. Curr. Opin. Biotechnol. 11 (2000), pp. 554–564. SummaryPlus | Full Text + Links | PDF (234 K)

6. V.P. Miller, A. Tschirret-Guth and P.R. Ortiz de Montellano. Arch. Biochem. Biophys. 319 (1995), pp. 333–340. Abstract | PDF (735 K)

7. J. Geigert, D.J. Dalietos, S.L. Neidlman, T.D. Lee and J. Wadsworth. Biochem. Biophys. Res. Comm. 114 (1983), pp. 1104–1108. Abstract-MEDLINE  

There is a graphical abstract and a table that I can put up if anyone is interested.


  • Guest
« Reply #66 on: July 10, 2003, 12:27:00 PM »
Benzaldehyde (0,010 g, 0,1 mmol), sodiumpyruvate (0,205g), baker`s yeast (0,415 g) and citrate buffer (0,415 ml, pH 6) was placed into a 15 ml stainless steel vessel. The vessel was pressurised to 2000 psi by pumping dried liquid carbon dioxide into the vessel and stirred for 24 h at 33° C.

The vessel was than cooled to RT an slowly degassed.

82% yield of Phenylacetylcarbinol

US Pat 2003/0077769    Apr. 24, 2003

Patent WO0144486


  • Guest
I love 10mg synths. Let's scale this one up by
« Reply #67 on: July 10, 2003, 06:00:00 PM »
I love 10mg synths.

Let's scale this one up by a factor of 1000:

Benzaldehyde (10g), sodiumpyruvate (205g), baker`s yeast (415 g) and citrate buffer (415 ml, pH 6) was placed into a 15 l stainless steel vessel. The vessel was pressurised to 2000 psi (150 bar) by pumping dried liquid carbon dioxide into the vessel and stirred for 24 h at 33° C.
The vessel was than cooled to RT an slowly degassed.
(Note: not one word about workup of the glob of slime, how to keep it from foaming all over the place etc...)
82% yield of Phenylacetylcarbinol.


  • Guest
Workup and Vessel
« Reply #68 on: July 10, 2003, 06:32:00 PM »
The workup in the patent (example 1) was carried out by radial chromatography, but in the above theads are a lot of methods for the workup.

You think, you need a vessel about 15 l for a 10 g (benzaldehyde) synthesis ?

I think it is only a question of the pressue (CO2) and you can take a   3-4 l vessel for a 30 g (benzaldehyde) synthesis.


  • Guest
Probably so. The CO2 should be supercritical...
« Reply #69 on: July 10, 2003, 07:44:00 PM »
Probably so. The CO2 should be supercritical at that pressure (I think), so it will also act as a solvent. It's not the pressure that counts, some volume is definitely needed.


  • Guest
Reductive amination
« Reply #70 on: October 09, 2003, 08:10:00 AM »
So, has anyone tried using the Sodium Borohydride reduction with methylamine? Works with amazing yield for MDMA so is this a viable reduction method for L-PAC? I always thought this to be the best high yield, large scale amination I had seen. And let's face it, if one is going to go through all these hassles to produce a relatively valueless product such as ephedrine, when it can be acquired easier than one might think, it should be done on a large scale to justify the procedure. To me it does not seem much easier than the conversion of safrole to MDMA using a good wacker oxidation method yet it is worth far less.


  • Guest
I thought Id throw this patent up while we`re...
« Reply #71 on: October 09, 2003, 10:06:00 AM »
I thought Id throw this patent up while we`re at it.
It might be of interest of those out there who are lazy like me.Sorry If it has been posted previously.

It describes a simular process as above,only it claims it can be worked in in non fermenting conditions,using common solvents at lower temps.

Patent US6271008

Recycling may raise yield,but still, it looks a lot more like tweeer chemistry than ever before.
Sorry ;)


  • Guest
Pyruvic Acid
« Reply #72 on: October 09, 2003, 12:19:00 PM »
Pyruvic acid [127-17-3] , 2-oxopropanoic acid, pyroracemic acid, a-ketopropionic acid, H3C–CO–COOH, Mr 88.06, is the most important a-oxocarboxylic acid. It plays a central role in energy metabolism in living organisms [8]. During exertion, pyruvic acid is formed from glycogen in the muscle and reduced to lactic acid [79-33-4]. In the liver, pyruvic acid can be converted into alanine [56-41-7] by reductive amination. Pyruvic acid was discovered and first described in 1835 by BERZELIUS [9].
Pyruvic acid is totally miscible with water, ethanol, and ether. Pyruvic acid exists in the keto form; the enol form cannot be detected [10].

Chemical Properties Pyruvic acid reacts as both an acid and a ketone. It forms, for example, oximes, hydrazones, and salts. 4,5-Dioxo-2-methyltetrahydrofuran-2-carboxylic acid [24891-71-2]  is formed from pyruvic acid either slowly on standing or more quickly under acid catalysis [11].

On standing in aqueous solution, pyruvic acid polymerizes to higher molecular mass products via the dimeric ketoglutaric acid  [19071-44-4] and the trimeric aldol product [12] , [13].
Like all 2-oxo acids, pyruvic acid eliminates carbon monoxide on treatment with concentrated sulfuric acid [14].
Oxidation of pyruvic acid gives acetic or oxalic acid [144-62-7] and carbon dioxide, depending on the conditions [15]. Lactic acid is obtained by reaction with reducing agents [1].
Reaction of a-amino acids with pyruvic acid gives, besides carbon dioxide, alanine [56-41-7] (transamination reaction) and the corresponding aldehyde with one carbon atom less [16]. Alanine is also obtained by reductive amination of pyruvic acid [1]. Phenylethylamines react with pyruvic acid to form the corresponding tetrahydroisoquinolines via the Bischler – Napieralski reaction [17]. Reaction with o-phenylenediamines gives quinoxalinols [18]. In a similar reaction the corresponding hydroxypteridines are obtained from 4,5-diaminopyrimidines and pyruvic acid [19]. Pyruvic acid reacts with aldehydes to form the corresponding a-keto-g-hydroxy acids, which then cyclize to butyrolactone derivatives [1] . Friedel – Crafts type reactions of aromatic compounds with pyruvic acid yield diarylpropionic acids. These compounds have achieved a certain degree of importance because they provide a good route to 1,1-diarylethylenes by dehydration and decarbonylation [15] , [20].

Production On an industrial scale, pyruvic acid is produced by dehydration and decarboxylation of tartaric acid [87-69-4] [21]. In this process, pyruvic acid is distilled from a mixture of tartaric acid and potassium and sodium hydrogen sulfates at 220 °C. The crude acid obtained (ca. 60 %) is then distilled in vacuum. The reaction temperature can be lowered to 160 °C by adding ethylene glycol [107-21-1] [22]. Pyruvic acid can also be obtained by the gas-phase oxidation of lactic acid [23] , but this process has not been successful industrially. In contrast, microbial oxidation of D-lactic acid by a new process results in high yields [24]. Microbial oxidation of 1,2-propanediol [57-55-6] to pyruvic acid has also been described [25]. Another process describes the hydrolysis of 2,2-dihalopropionic acids to pyruvic acid [26]. A process for the oxidation of methylglyoxal [78-98-8] with halogens has recently been published [27].

Uses Pyruvic acid is used mainly as an intermediate in the synthesis of pharmaceuticals. It is also employed in the production of crop protection agents, polymers, cosmetics, and foods.

Storage and Quality Specifications Pyruvic acid is stored and transported in tightly closed polyethylene containers. It can be kept for only a limited period and must therefore be stored in refrigerated areas at a maximum of 10 °C. At higher temperature, explosion can occur through spontaneous self-condensation [28]. The concentration of the commercial product is determined acidimetrically and decreases by ca. 1 % per month during storage.

Toxicology Pyruvic acid has a corrosive effect and irritates the eyes, skin, and respiratory passages.

[1] A. J. L. Cooper, J. Z. Ginos, A. Meister, Chem. Rev. 83 (1983) 321.
[8]  K. Schreiber: Die Brenztraubensäure und ihr Stoffwechsel, Editio Cantor, Aulendorf 1956.
[9]  J. J. Berzelius, Ann. Phys. 36 (1835) 1.
[10]  A. Schellenberger, K. Winter, Chem. Ber. 92 (1959) 793.
[11]  L. Wolff, Justus Liebigs Ann. Chem. 317 (1901) 1.
[12]  H. Goldfine, Biochim. Biophys. Acta 40 (1960) 557.
[13]  A. Schellenberger, E. Podany, Chem. Ber. 91 (1958) 1781.
[14]  A. Bistrzycki, B. v. Siemiradzki, Ber. Dtsch. Chem. Ges. 39 (1906) 58.
[15]  S. Patai, S. Dayagi, J. Chem. Soc. 1958, 3058.
[16]  R. M. Herbst, L. L. Engel, J. Biol. Chem. 107 (1934) 505.
[17]  G. Hahn, A. Hansel, Ber. Dtsch. Chem. Ges. 71 (1938) 2163.
[18]  O. Hinsberg, Justus Liebigs Ann. Chem. 237 (1887) 327.
[19]  G. B. Elion, G. H. Hitchings, P. B. Russel, J. Am. Chem. Soc. 72 (1950) 78.
[20]  Bayer, 

Patent DE2830953

, 1978 (W. Meyer, H. Rudolf, E. Cleur, E. Schoenhals). =

Patent US4369206

[21]  J. W. Howard, W. A. Fraser, Org. Synth. Coll. Vol. 1 , 475.

[22]  J. D. Riedel,

Patent DE281902

, 1913.
[23]  C. H. Boehringer Sohn,

Patent DE523190

1931 (F. Zumstein).
[24]  BASF,

Patent EP313850

1988 (B. Cooper).
[25]  Y. Izumi, Y. Matsumura, Y. Tani, H. Yamada, Agric. Biol. Chem. 46 (1982) 2673.
[26]  Dow Chemical,

Patent US3524880

1966 (L. H. Lee, D. E. Ranck).
[27]  BASF,

Patent DE3219355

1982 (U. R. Samel, L. Hupfer).
[28]  Sichere Chemiearbeit 29 (1977) 87.


  • Guest
Single Cell Proteins
« Reply #73 on: November 01, 2003, 10:45:00 PM »
While there are some changes necessary in the inputs and outputs for producing L-PAC, as opposed to simply growing yeast for protein; this article by Litchfield about culturing single cell proteins should bee very helpful in gaining understanding of what's required  ;)

Bacteria are also capable of growing on a variety of raw materials, ranging from carbohydrates such as starch, and sugars, to gaseous and liquid hydrocarbons such as methane and petroleum fractions, to petrochemicals such as methanol and ethanol. Suitable nitrogen sources for bacterial growth include ammonia, ammonium salts, urea, nitrates, and the organic nitrogen in wastes. A mineral nutrient supplement must be added to the bacterial culture medium to furnish nutrients that may not be present in natural waters in concentrations sufficient to support growth.
The bacterial species most likely to be used for singly-cell protein production grow best in slightly acid to neutral pH in the range 5 to 7. The bacteria should also be able to tolerate temperatures in the 35 to 45 C range, because heat is released during the bacterial growth. The use of temperature-tolerant strains will minimize the need for refrigerating the water that cools the fermentation vessel. Bacterial species cannot be used for single-cell protein production if they are pathogenic for plants, animals or humans.
Bacterial single-cell protein may be produced in conventional hatch systems in which all of the nutrients are supplied to the fermentor initially; the cells are harvested when they have con­sumed the nutrients and stopped growing. However, in the more advanced production methods the nutrients are supplied continuously in the concentrations needed to support bacterial growth and the cells are harvested continuously once the popu­lation reaches the desired concentration.
The concentration of the carbon and energy source usually ranges from 2 to 10 per cent in batch processes. In the continu­ous process the supply of the carbon source is regulated so that the concentration in the growth medium does not exceed that required by the growing bacterial cells. This concentration will generally be lower than those used in batch processes.
Maintaining sterile conditions during single-cell protein pro­duction is very important because contaminating microorganisms grow very well in the culture medium. The incoming air, the nutrient medium and the fermentation equipment must be sterilized in all bacterial single-cell protein processes, and sterile conditions; must be maintained throughout the produc­tion cycle.   
In continuous processes the nutrients are replenished as they are consumed to maintain the concentrations needed by the bacteria. The solution containing the bacteria is drawn off, treated to cause the bacteria to agglomerate or flocculate, and centrifuged. The liquid may then be recycled in the fermentor while the bacteria are spray-dried and ground to yield the final product.
After the nutrients are sterilized and intoduced into a fermentation vessel and inoculated with the bacteria to be grown. The vessel, which is known as a 'bioreactor', must be supplied with sterile air and with cooling water to prevent the heat released during fermentation from building up and killing the cells. The cooling water is circulated in either the outer jacket of the fermentor or through internal cooling coils.
The vessels are also fitted with instruments that measure and control the pH and temperature of the contents and the concent­ration of dissolved oxygen. The exhaust air from the bioreactor contains carbon dioxide that may be separated and compressed for sale to industrial users of carbon dioxide.
After the bacteria are removed from the fermentation tank, they must he separated from the culture broth, which is usually done by adding chemicals that will cause the cells to clump and then centrifuging them. The separated cells are dried to yield a product that will be stable during shipment and storage. Finally, there must be equipment for grinding and packaging the cells and a system for treating and recycling the spent culture fluid.
Oxygen transfer to the cells in the fermentor is a critical factor in obtaining growth rates and yields that are economically satisfactory. A variety of fermentor designs can provide suitable aeration. The most commonly used are the baffled stirred-tank reactor and the air-lift fermentor.
Although considerable research was conducted on the production of bacterial single-cell protein during the 1960s and early 1970s, Imperial Chemical Industries (ICI) in the United Kingdom developed the only process to reach a commer­cial scale of operation. In the ICI process the bacterium Methylophilas methvlotrophus, which has a generation time of about 2 hours, is grown continuously with methanol as the substrate and additional nutrients including ammonia and the minerals phosphorus, calcium and potassium. The company developed for the process a unique air-lift fermentor with a capacity of 1500 cubic metres. The fermentor design minimizes the requirements for cooling the vessel and the problem of oxygen limitation.
Schematic diagram of a baffled stirred tank fermentor. The air introduced into the fermentor is dispersed by the propellor-like agitator. The baffles projecting from the side of the tank shown in cross-sectional view help to ensure that the contents of the tank are thoroughly mixed and oxygenated.

In 1980 ICI commissioned a plant, with the capacity of pro­dicing 50 000 metric tons of single-cell protein every year, at Billingham, England. The plant has since been operated inter­mittently, with a production of 6000 metric tons per month. The bacteria grow on methanol as their energy source. Two metric tons of methanol yield about 1 metric ton of dry 'Pruteen' single-cell protein. The dried product, which contains about 72 per cent protein and 8 per cent moisture, has been sold as an animal feed supplement in Western European markets.
With soybean meal now costing just $190 per metric ton, however, 'Pruteen' is no longer competitive as an animal feedstuff and the plant is not being operated on a commercial scale at present. Nevertheless the development of the ICI process for making the bacterial single-cell protein exemplifies the application of modern chemical engineering to the field of biotechnology.
During the development of 'Pruteen' ICI scientists investigated the possibility of improving the conversion of methanol it single-cell protein by genetically modifying the ability of M. methvlotrophus to use ammonia. They introduced into the bac­teria a gene for an ammonia-assimilating enzyme that is more efficient than the endogenous bacterial enzyme. Although the new gene was stable in the bacteria and was expressed there, only a 3 to 5 per cent increase in single-cell protein yield was, obtained with the genetically modified strain of bacteria.
Modern technology for producing yeast single-cell protein has largely developed since World War II. Today, yeast products for human or animal consumption are produced on a commer­cial scale in many countries. In addition, baker's yeast, which is grown on molasses, is sold as a food flavouring and nutritive ingredient in addition to being used as a leavening agent.
Yeast can be grown on a number of substrates. These include carbohydrates, both of the complex type, such as starch, and of the simple type, such as the sugars glucose, sucrose and lactose. Alternatively, sugar-containing raw materials such as corn syrup, molasses and cheese whey can be used. Some yeasts are able to grow on straight-chain hydrocarbons, which are obtained from petroleum, or on ethanol or methanol.
In addition to a carbon source, a nitrogen source is required. The nitrogen can be provided by addition of ammonia or ammonium salts to the culture medium. A supplement of min­eral nutrients is also required.
The requirements for production of yeast single-cell protein are similar to those previously described for production by bacteria. The yeast should have a generation time of about 2 to 3 hours. It should he pH- and temperature-tolerant and genetically stable, giving satisfactory yields from the substrate used, and not cause disease in plants, animals or humans.
The, technology for producing yeast single-cell protein is also similar to that for making the bacterial products. The baffled, stirred-tank fermentor is the most common type of vessel for yeast single-cell protein production, but air-lift fermentors are also used. As in the bacterial cultures, heat is released during yeast growth and the fermentor must be pro­vided with a cooling system.
The yeast fermentations may be operated either in the batch or continuous mode, or by a third mode called 'fed-batch'. In fed-batch processes the substrate and other nutrients are added in an incremental manner to meet the growth requirements of the yeast while maintaining very low nutrient concentrations in the growth medium at any time. This method yields 3.5 to 4.5 per cent dry weight of product compared with the 1.0 to 1.5 dry weight of product yielded by batch cultivation. Cells grown by fed-batch processes are harvested as they are in the batch: mode of production.
Although batch and fed-batch culture systems have been used in baker's yeast production for many years, only recently has the technology been available for monitoring and adjusting the pH and substrate concentrations to permit the continuous type of operation. Yeast cell concentrations of up to 16 per cent (dry weight) can be obtained in the continuous culture opera­tions.
Yeasts have certain advantages over bacteria for production of single-cell protein. For one, the yeasts tolerate a more acid environment, in the range of 3.5 to 4.5 instead of the near ­neutral pHs preferred by bacteria. Consequently, yeast proces­ses can be operated in a clean but non-sterile mode at a pH of 4.0 to 4,5 because most bacterial contaminants will not grow well in this degree of acidity. For another, yeast cell diameters are about 0.0005 centimetres as compared with 0.0001 cen­timetres for bacteria. Because of their larger size yeasts may be separated from the growth medium by centrifugation, with­out the need for a flocculation step.
Yeast single-cell protein production depends upon meeting the oxygen demand of the growing cultures. Yeasts grown on carbohydrates generally require about 1 kilogram of oxygen per kilogram dry weight of cells and when grown on hydrocarbons they need about twice that much. Air, which is sterilized by filtration, is supplied to the fermentor through a perforated screen or perforated pipes in the bottom of the vessel, or by a rotating aeration wheel or air-lift device similar to those used for culturing bacterial cells.
Yeast single-cell protein may be produced either under sterile, or clean but non-sterile, conditions. In a typical batch or fed-batch non-sterile operation in which carbohydrate is used as the carbon and energy source the medium is sterilized by passing it through a heat-exchanger and then charged into clean fennentors. Contamination control is based on having a pH of 4.0 to 5.0, supplying sterile air, and maintaining large populations of yeast cells in the fermentor to overwhelm any small numbers of contaminating microorganisms. In some continuous yeast fermentations that use hydrocarbons or ethanol as the substrate, completely sterile conditions may he needed to achieve the desired yields and product quality.
Candsda units, which is known as torula yeast and used both as an animal feed supplement and for human consumption, is manufactured from a wide range of raw materials, among which are ethanol, the sulphite waste liquor from paper mills, normal paraffin hydrocarbons and cheese whey.

:)  ;)  ;D


  • Guest
thanks lugh
« Reply #74 on: November 25, 2003, 10:12:00 PM »
thats a good piece of information again, love it.

But the problem is actually that ppl are talking here about biosynthesis who are obviously not even able to make some acetal or benzaldehyde from OTC chems. Thats the only problem - the easy biosynth is posted already. Not more difficult as brewing beer - what is not so easy as some may think btw..

One last piece of information:
How to determine the biosynthesis process is actually over?
- it doesnt smell like oil of bitter almonds anymore.
thats it, the technique is called "nosing", ask DWARFER.....

I am outa this.


  • Guest
Re: thats a good piece of information again,...
« Reply #75 on: November 28, 2003, 12:53:00 AM »

thats a good piece of information again, love it.

But the problem is actually that ppl are talking here about biosynthesis who are obviously not even able to make some acetal or benzaldehyde from OTC chems. Thats the only problem - the easy biosynth is posted already. Not more difficult as brewing beer - what is not so easy as some may think btw..

No, that's not true sorry. Senior chemistry bees have continually given the misleading impression that there was vital or atleast important information mission necessary to success.

What do you mean beer-making is hard?!?!?!?!!?!??! That's an infuriating implication to make at this late stage.

Oh so it is a walk in the park then, I thought so, thats what the first references I've read translated to a long time ago..... seemed straightforward and complete enough, it seems it always was.

I think Ill trust the references on the yeast species, candida utilis.

The benzaldehyde and acetaldehyde was always something to work at, it's just that uncertainties were portrayed.

Ohh you meant difficult as in you'd have to follow instructions and a few parametres.


  • Guest
making good beer is an art
« Reply #76 on: November 28, 2003, 02:00:00 PM »
I didnt write it is difficult - but it is more than throwing some yeast in a bucket with sugar.

I see Java has provided the post number but no direct link. Here it is:

Post 388164

(Organikum: "substituted hydroxyphenylacetone", Novel Discourse)
and followups

Post 400469

(Organikum: "L-PAC reductive alkylation", Novel Discourse)

The procedure as described is straight after an east german patent and works fine. Tried and true. And probably the way most ephedrine on the world is manufactured in China and India. Low tech process.

actively fermenting saccaromyces cerevesiae aka bakers yeast is to use - actively fermenting says aerated and feeded with dextrose. ph-control is important. Brewers wort and acetaldehyde are important but can be substituted by diminished yields.
If your batch after 10 hours of active fermentation still smells like christmaspunch use another sort (strain) of bakers yeast.
Brewers wort here is wort before the hops are added - the temperature of the wort must never have exceeded 78°C or the essential enzymes are destroyed and its near to worthless.

and now I am realy out here.


  • Guest
some L-PAC info
« Reply #77 on: December 04, 2003, 02:16:00 AM »
Review: Application of beta-keto acid decarboxylases in biotransformations
H. Iding, P. Siegert, K. Mesch and M. Pohl

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1385(2), 307-322 (1998)



The advantages of using enzymes in the synthesis of organic compounds relate to their versatility, high reaction rates, and regio- and stereospecificity and the relatively mild reaction conditions involved. Stereospecificity is especially important in the synthesis of bioactive molecules, as only one of the enantiomeric forms usually manifests bioactivity, whereas the other is often toxic. Although enzymes which catalyze asymmetric carbon-carbon bond formation are of great importance in bioorganic chemistry, only a few examples are known for thiamin diphosphate (ThDP)-dependent enzymes, whereas transformations using e.g. aldolases, lipases and lyases are well documented already. The present review surveys recent work on the application of pyruvate decarboxylase and benzoylformate decarboxylase in organic synthesis. These enzymes catalyze the synthesis of chiral beta-hydroxy ketones which are versatile building blocks for organic and pharmaceutical chemistry. Besides the substrate spectra of both enzymes amino acid residues relevant for substrate specificity and enantioselectivity of pyruvate decarboxylase have been investigated by site-directed mutagenesis.


  • Guest
immobilized yeast
« Reply #78 on: January 24, 2004, 05:40:00 PM »
Production of yeast-alginate pearls:
(hope alginat is alginate in english LOL)
2,5g yeast is mixed with 3ml waterby shaking.
0,25g sodiumalginate is shaken with 7ml of water.
Then the yeast suspension is given to the dissolved alginate.

0,3g CaCl2 is dissolved in 15ml water and stirred like hell (vortex stirring). Whilst stirring the yeast/alginate mixture is added to the CaCl2/water dropwise using a syringe. The syringe should be hold vertically when doing this.

3mm diameter pearls of yeast enclosed in alginate will drop out and can be removed by using an ultrahightech teasieve device.

voila - immobilized yeast.

I know I said I am out here, but thats to good to disclose it I believe. And it might come VERY handy not only in the L-PAC process which btw is called "acloin condensation" in newer publications. Ah these chemists - always a new name for an old reaction.....



  • Guest
PDC questions
« Reply #79 on: January 29, 2004, 01:35:00 AM »
sorry about that outburst up there, it looks disgraceful and immature now. what a **cken baby.

It seems like the biotranformation is highly dependent on Can high PDC activity the type of PDC and yeast one can get a hold of, including mutated forms.

Organikum, I'm not clear-minded regarding whether acetaldehyde addition is beneficial in a batch process...

Is alcohol dehydrogenase activity decreased with higher concentrations of acetaldehyde already present, necessarily?

Is it possible to produce acetaldehyde in situ before addition of benzaldehyde in a second phase of the fermentation process? Perhaps after the addition of more yeast, and developing this second culture.

(see: 'LPhenylacetylcarbinol is generated biologically through the pyruvate decarboxylase-mediated condensation of added benzaldehyde with acetaldehyde generated metabolically from feed stock sugars via pyruvate...')

Do we know the response time of increased PDC activity as a result of reduced aeration? (For the purpose of having high PDC activity at the moment of substrate addition(s))

Do we know the amount of yeast that is required for developing enough of it in a specific time for a given quantity of benzaldehyde feedstock? An estimate?

Tell me if I'm unclear, it's happened before.