Cetus process

P20 is involved in the so-called Cetus process , in which D-fructose is produced from cheap D-glucose (Fig. 16.2-28). 

Figure 16.2-28. Isomerization of D-glucose to D-fructose with pyranose oxidase (P20) and coupling of hydrogen peroxide to a synthetic reaction (Cetus process).

PLATE 4 Bioreactors that use mammalian cells, like this tower fermentor, are on the cutting edge of new biotechnology manufacturing processes. Courtesy, Cetus Corporation. 

Cetus A four-stage fermentation process for making propylene oxide from glucose. The product is obtained as a dilute aqueous solution. Developed by Cetus Corporation in the 1970s but not commercialized. 

Taq polymerase is useful in the polymerase chain reaction (PCR) and the European patent rights for the PCR process and Taq polymerase were sold by Cetus in the early 1990 s to Hoffmann La Roche for approximately 300 milhonUS dollars. 

Kaiy Mullis and others at Cetus Corporation in Berkeley, California, invented a technique for multiplying DNA sequences in vitro by, the polymerase chain reaction (PCR). PCR has been called the most revolutionary new technique in molecular biology in the 1980s. Cetus patented the process, and in the summer of 1991 sold the patent to Hoffmann La Roche. Inc. for 300 million. 

Despite the lack of enantioselectivity, such reactions may still be interesting for an individual process. For example, an elegant and efficient industrial application has been elaborated for the production of - racemic - propylene oxide (Cetus procedure) by Neidleman [78]. However, to the best of our knowledge, severe competition with conventional chemical processes occurred and this procedure has not been used industrially. 

The PCR was invented by Kary B. Mullis and developed by him and his co-workers at Cetus Corporation. It makes use of the enzyme DNA polymerase, discovered in 1955 by Arthur Kornberg and associates at Stanford University. In living cells, DNA polymerases help repair and replicate DNA. The PCR makes use of a particular property of DNA polymerases their ability to attach additional nucleotides to a short oligonucleotide primer when the primer is bound to a complementary strand of DNA called a template. The nucleotides are attached at the 3 end of the primer, and the nucleotide that the polymerase attaches will be the one that is complementary to the base in the adjacent position on the template strand. If the adjacent template nucleotide is G, the polymerase adds C to the primer if the adjacent template nucleotide is A, then the polymerase adds T, and so on. Polymerase repeats this process again and again as long as the requisite nucleotides (as triphosphates) are present in the solution, until it reaches the 5 end of the template. 

FIGURE 6 The PCR process. Courtesy of PE Cetus Instruments. (From Schantield, M. S. (2000). Deoxyribonucleic Acid/Polymerase Chain Reaction. In Encyclopedia of Forensic Sciences (Siegel, J. A., Saukko, P. J., and Knupfer, G. C., eds ), Academic Press, London, p. 517.)... 

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