Manipulation of Bacteria by
Genetic Engineering
Genetic manipulation by the deliberate introduction of defined
genes into a specified organism is a very powerful technique which is
relatively new and certainly in constant development, sometimes at phenomenal
rates of progress. The techniques have produced some exciting hybrids in all
areas of research, both microscopic; bacteria and fungi, usually described as
recombinants, and macro-scopic; principally higher plants and animals, commonly
described as transgenics. The latter term refers to the principle of deliberate
transfer of a gene from one organism to another in which it is not normally
resident. This earns the incom-ing gene the title of ‘foreign’. Some examples
of these which are relevant to environmental biotechnology will be discussed
later.
Some of the developments are
of great potential interest and represent some exciting and innovative work.
However, it must be said that, in practice, a very tiny proportion of all
endeavour in the name of environmental biotechnology has, or is likely to have
in the future, a direct reliance for its effectiveness on the type of recombinants
and transgenics currently being developed. This is not because of the limits of
genetic engineering, which in principle are almost boundless, given sufficient
resources, but because of cost. It is a principal factor as the technology and
research to produce transgenic organisms attract an inherently high price.
While such a situation may be sustainable by pharmaceutical compa-nies and
perhaps to a lesser extent, agribiotechnology companies possibly able to
command a high return on sales of the product, it is rarely sustainable in
appli-cations of environmental technology. Few commercial organisations are
excited at the prospect of spending a large proportion of their income on waste
disposal for example, and will normally only do so when absolutely necessary.
There are other factors
which affect the suitability of transgenic organisms in this science due to
current requirements for containment. In addition, the way in which such a
recombinant is utilised may cause problems of its own. For example, if the
recombinant is a micro-organism structured to improve the rate of degradation
of a pollutant, its performance may be exemplary in laboratory conditions but
when it is applied in bio-augmentation it is in competition with indigenous
species which could outgrow the recombinant. The novel bacterium may also lose
its carefully engineered new capability through normal transfer of genes given
the high level of promiscuity between bacteria. A highly controlled and
contained environment such as a bioreactor may circumvent some of these
objections but it is not always practical to move the contamination to the
solution rather than the solution to the contamination. Again this involves
expense and practical considerations, not least of which are safety concerns associated
with the transport of contaminated material.
In reality, there is rarely
any need to use recombinants or transgenics and it is far more likely that the
required metabolic capability will be provided by indigenous organisms, or ones
which have been trained for the task. There are, however, some exotic and
ingenious applications, and by way of illustration, some examples are given
here. The aim is to provide an overview of some of the more frequently used
technologies together with specific examples. There are very many excellent
textbooks and specialised publications which should be consulted should a more
detailed and working knowledge be required. However, an overview of the
principles of genetic engineering are given here for the benefit of those
unfamiliar with the technology.
Related Topics
Privacy Policy, Terms and Conditions, DMCA Policy and Compliant
Copyright © 2018-2023 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.