Environmental Biotechnology - Theory and Application

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270 Environmental Biotechnology


related issues, of course, and both may be addressed by one of two general
approaches:apriorimethods to avoid the problem in the first place ora posteriori
to clean it up more efficiently after the event. Clean production methods, which
have been variously discussed in Chapters 4 and 10, seem likely to play a grow-
ing part in achieving the former. The use of various production biotechnologies
will limit the environmental impact of ever more industrial processes by reducing
their energy demands, the strength of effluents generated, the amount of waste
requiring ultimate disposal and so on. The growing importance of biocatalysis,
and the general use of biological macromolecules in manufacturing procedures
will, inevitably, lead to the development of novel and innovative techniques for
many substances currently generated by conventional means. There are many
candidates for the forthcoming major roles in the bioindustrial production cycles
of the near future but probably amongst the most revolutionary and beneficial are
likely to be found amid the ranks of the extremophiles, which were previously
discussed in Chapter 3. Extremozymes isolated from these bacteria and archaea,
which dwell happily in some of the most unlikely and biologically challenging
of environments on the planet, offer the potential to catalyse reactions previously
the exclusive realm of physical chemistry. Their potential lies both in primary
action and secondary effect. The first of these utilises enzymes obtained to bring
about the desired effect, where such specificity of action is a natural characteris-
tic of the donor microbe. Secondary effects arise by virtue of the elucidation of
the functionally key features of naturally occurring substances. This allows the
same mechanisms to be incorporated into artificial chemicals which subsequently
achieve a goal for which no direct analogue exists in nature. In this respect, for
instance, further study of extremozymes isolated from hyperthermophilic organ-
isms may well permit the mechanism of their heat tolerance to be discerned and
the appropriate means incorporated into other, non-natural catalysts.
The value of the extremozyme contribution has already been noted in the now
well-established PCR technique, which enabled a major jump ahead to be made
in the whole science of biotechnology itself. In addition, the commercial use
of an enzyme obtained from another thermophile to increase the efficiency of
cyclodextrin production from cornstarch is a currently known example of clean
technology. Though these compounds are valued in the pharmaceutical and food
industries, where they principally aid the stabilization of volatile ingredients, the
process can still fairly be said to have an environmental component. Improved
manufacturing efficiencies typically go hand in hand with reduced pollution,
waste production or energy demand. In the future, this aspect of industrial activity
seems set to assume far greater importance and extremophile research may well
provide many of the necessary tools to make it possible.
Thus, hyperthermophilic extremozymes have potential applications in many
industries, offering amylases for confectionary or alcohol production, proteases
for amino acid production, baking, brewing and detergents, xylanases for paper

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