Chemistry Reference
In-Depth Information
3
Production of industrial enzymes
Tim Dodge
The use of enzymes in food applications has been around for centuries.
1
Some of the
first examples were the use of naturally occurring enzymes in the source substrate, such as
α
-amylases that are naturally present in grains used for brewing. Enzymes were also extracted
from both plant and animal sources. Then came the use of microbially produced enzymes,
where the enzymes were the natural products of the microbial culture. Today, most enzymes
are still produced microbially; however, many of the enzymes are no longer native enzymes,
but engineered versions. Protein engineering allows the properties of the enzyme to be
optimized for its specific use. Many of the applications today are only possible by the use of
these specialized products.
Protein engineering is practised through the use of recombinant DNA (rDNA) technology.
The same rDNA technology is also utilized to design the microbial strains used to produce
the enzyme. The hosts used for enzyme manufacture are becoming more limited in number.
At the same time, the source of the enzyme is coming from a wider variety of organisms.
This creates a host-platform-centred approach that offers numerous advantages. Efforts can
be focused on developing the molecular biology tools required for the smaller set of host
organisms. More in-depth knowledge can be gathered and applied to improve these strains by
conferring the properties important for industrial enzyme manufacture. These include factors
such as fast and efficient growth on simple media, high extracellular enzyme expression and
low level of other background proteins, among others. These advantages go beyond those
just for strain development, but also for the fermentation, recovery and formulation process.
Developing numerous processes for different enzymes is simplified when the same host strain
is used, as knowledge of the strain is leverageable. Specifically, the requirements for growing
and recovering from the same strain remain the same and this provides a basis to develop
a process unique to each enzyme. Requirements for growing the strain remain the same and
process conditions become more similar. This advantage continues through to the industrial
production plant, where similar processes can reduce capital equipment requirements and
ease plant operations.
3.1
APPLICATIONS RESEARCH AND PROTEIN
ENGINEERING
Although this topic will be covered in more detail in another chapter, we will nonetheless
introduce the subject here. Modern industrial biotechnology is highly integrated and not just
