|
1. What is an enzyme?
Enzymes are macromolecules, mostly of protein nature, that occur in
all living organisms. Acting as natural catalysts, they enable the biochemical
reactions necessary for life to take place by increasing the reaction
rates. Enzymatic reactions require neither high temperatures nor high
pressure conditions, and are therefore less energy-intensive than processes
dependent on chemical catalysts. Enzymes have a high specificity. In general,
an enzyme catalyzes only one reaction type and operates on only one type
of substrate.
Many different enzymes exist in organisms, working in the digestive system,
in the metabolic processes and helping the synthesis of certain compounds.
Some pesticides and herbicides work by interfering with enzyme systems,
or by destroying them altogether.
2. Enzymes: Key data from ancient times up to the present day
Ever since antiquity, mankind has made use of the catalytic, or "modifying",
properties of certain enzymes for the production of food. Although enzymes
have been among us since time immemorial, it was only recently that that
their potential was realised in the food, textile, leather, and paper
industries, in the wastewater-treatment sector, and as a washing-detergent
additive. Here a few key data on enzymes:
|
2000 BC: |
The ancient Egyptians
and Sumerians discover the process of fermentation and use it
to brew beer and to make bread and cheese. |
|
800 BC: |
The use of calf stomachs
(and the enzyme chymosin) in the production of cheese is described
in Homer’s "Iliad" and "Odyssey". |
|
1833: |
The enzyme complex
of malt is isolated for the first time. |
|
1874: |
Chymosine is extracted
from calf stomachs for the first time. |
|
1874: |
Glucose is converted
into ethanol and carbon dioxide using cell-free yeast extract,
proving that the conversion is due to the action of enzymes and
not to that of living yeast cells themselves. |
|
ca. 1900: |
A method for the
industrial production of the enzyme amylase (starch-degrading
enzyme), which occurs in the fungus Aspergillus oryzae, is developed.
|
|
1913: |
The effectiveness of
washing detergents is enhanced by the addition of the proteolytic
(protein-degrading) enzyme trypsin, which is obtained from animal
pancreas. The product is marketed under the "Burnus" trademark
until well into the 1960s. |
|
1917: |
For the first time
an amylase from a bacterium (Bacillus subtilis) is used to replace
the acids, bases, and oxidants that have previously been used
in the desizing of textiles (removal of the starch used in textile-manufacturing
processes). Mass production of the enzyme begins only after the
end of the Second World War. |
|
1950: |
The first washing
detergent using a bacterial protease (proteolytic enzyme) in place
of pancreatic trypsin is developed. |
|
ca. 1960: |
The enzyme amyloglucosidase
is first used to fully degrade starch into glucose (sugar syrup),
which rapidly leads to the use of acid becoming virtually redundant
in the production of glucose. |
|
1971: |
Bacterial chymosin
is available for the first time as a substitute for the calf-stomach
enzyme for the production of cheese. |
|
ca. 1980: |
Enzymes are used
for the first time to enhance the efficiency of chlorine in paper-bleaching
processes, enabling the consumption of chlorine to be cut drastically.
|
|
1982: |
Amylase for the
starch industry is produced in genetically modified microorganisms.
|
|
1988: |
Chymosin is first
produced in genetically modified yeast cells. |
|
1997: |
Chymosin from genetically
modified microorganisms is given a marketing licence in Germany.
|
|
1988-1999: |
Many of the enzymes
used in the food sector are produced by genetic modification.
Additionally, in washing detergents enzymes are in use that are
modified in terms of their molecular structure for special applications.
Similar developments are predicted for the food industry. |
|
