Here is some background leaving open a few questions.
Dairy industry cautious on transgenic enzymes
Nikkei Industrial Daily, Aug. 20, 1997
Fearing a consumer backlash, the dairy industry is taking a cautious stance
on
genetically engineered enzymes.
Chymosin, commonly known as rennin, is an enzyme used in cheese making to
coagulate milk. Since the enzyme must be extracted from the lining of cows'
stomachs, supplies of natural chymosin are limited.
Cheeses can be made with enzymes extracted from mold, but they are not as
aromatic or flavorful as those made with chymosin.
Genetic-recombination technology offers producers the prospect of an
unlimited and cheaper supply of chymosin.
The technology, which is widely used in the U.S. and the U.K., creates
genetically engineered chymosin that is 40-50% less expensive than the
natural
enzyme.
In fact, industry analysts in Japan estimate that large domestic cheese
producers could save almost 8 million yen (about 68,000 dollars) a year by
using the genetically engineered enzyme.
And as for the enzyme's safety, the Ministry of Health and Welfare back in
1995 approved genetically engineered chymosin as safe for use in food
products.
So why have manufacturers shied away?
The main reason is their desire to avoid a consumer backlash stemming from
the heightened controversy over the safety of genetically engineered food
products.
Officials at Snow Brand Food Co., the country's top-selling cheese producer,
say consumers are not ready for the introduction of genetically engineered
food
additives. Smaller producers, meanwhile, are holding off until the major
makers
adopt the substance.
Manufacturers are also cautious about imported cheeses. Meiji Milk Products
Co. says its imported cheeses come only from countries where genetically
engineered enzymes are not in use. (More)
<<Nihon Keizai Shimbun, Inc. -- 08-21-97>>
----------------
>John Lippman, the marketing man at the Chris Hansen Company in Wisconsin, and
>who has a degree in veterinary medicine and worked for Pfizer, says they want
>to be open and honest, as well as, educational. I think he was trying to
tell
>me without telling me the whole story.
>
>In 1968 the World Health Organization had a meeting in Rome to look for acid
>protease, the active ingredient (?) in chymosin, the enzyme in calves'
stomach
>used for coagulating cheese. After World War II, the produdtion of cheese
had
>increased but there were not enough calves to meet the demand for rennet.
>
>This active ingredient is found in the 4th stomach of the calf (the
abomasum). An enzyme (What is the name of this enzyme - chymosin?) is
excreted and clots the colostrum which the calf drinks from the
>mother. The quality of the rennet (in this case is the colostrum digested
by the chymosin enzyme?) peaks at 10 days old, then pepsin begins to
>be produced to digest the other food the calf starts eating.
>
>WHO came up with microbial fermentation as a solution (which solution, a
solutionfor creating chymosin? or a solution to creating rennet by alternative
means?) but there are problems of flavor and texture with this form of rennet.
>
>Fifteen years ago, in 1982, Pfizer, a pharmaceutical company which used to
>have a food department, spent $2 billion on research to create an alternative
>rennet. They changed one bacteria - e coli K12 (how did they change one
bacteria? This may be where the genetic engineering came in. They may have
genetically engineering a new E. coli bacteria.) More is known about this
>non-pathogenic strain of bacteria than any other.
>
>This bacteria was used to ferment the chymosin inside a cell. It forms in an
>"inclusion body." This is like a plastic bag in the cell. This "plastic
bag"
>contains the solid which is used to make chymosin.
(It sounds like this new bacteria is used to "ferment" chymosin to stimulate
the production of more chymosin. Is this the case?)
>
>The "plastic bag" is broken open in a homogenizer and a centrifuge. These
>collect the solids from the cells and purify out all the other cell material,
>the "broth," and impurities. All the gene material is gone. (The gene
>material from the first effort? Or the gene material from each fermented
>batch? It's not clear yet where the genetic engineering takes place in this
procedure.)
>
>Activating prochymise through low Ph makes it the enzyme chymosin.
>(Where does prochymise come from and how is it activated to make chymosin?)
>
>(What gene exchange was made to make the original product?
>The presumption is that this has never had to be done again and that all
>subsequent chymosin is not from gene exchange, but from fermentation, just as
>lite beer is made. Is this true?)
>
>Unlimited supply, no animal involved.
>
>The Chris Hansen Company also makes probiotics and acidophilus -- organisms
by
>natural selection.
>
>Chymax is the trade name for chymosin. Kosher salt, the stabilizer popylene
>glycol, and caramel color are added.
>
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