The Way Ahead - Environmental Biotechnology: Theory and Application - page 276

biotechnologist. Humanity recently celebrated the turning of the millennium - the
passage of 40 generations of our species. On this basis, a bacterial 'millennium'
passes in less than a day. There is a tendency, particularly in older biology
textbooks, to describe bacteria and their kin as 'primitive life forms'. While, of
course, this is true in terms of relative organisational complexity, it can encour-
age a sort of unwarranted phylum-ist view of our own evolutionary superiority.
With 40 generations passing in under 24 hours and predating our own earliest
beginnings by several hundreds of millions of years, prokaryotes are clearly far
more highly evolved than ourselves or any other form of life on earth. Unsurpris-
ingly, then, many of the environmental problems encountered today have readily
available solutions which make use of the natural cycles, pathways and abilities
of entirely unaltered micro-organisms.
As this topic has been at pains to point out, while there may well be a role
for the use of GMOs in some applications, it seems unlikely that engineered
organisms will assume centre-stage in the field. Part of the reason is that there
may simply be no need; there are enough odd abilities around quite naturally.
Scientists from the US Geological Survey recently announced the discovery of
hydrogenotrophic archaean methanogens living 200metres below the surface of
Lidy Hot Springs, Idaho (Chapelle et al . 2002). This microbial community is
unlike any previously discovered; normally arachea seldom comprise more than
1-2%, but here, in conditions of low organic carbon content (around 0.27mg/l)
but significant levels of molecular hydrogen, they amount to around 99% of
the population. Under normal circumstances these archaeans, being less efficient
energetically, are out-competed by 'normal' carbon-eating microbes, but in the
absence of solar energy, which drives ecosystems based on utilising organic
carbon, conditions heavily favour them.
This has been seen as particularly relevant to the search for extraterrestrial
life, since finding living systems on earth in environments analogous to those
believed to exist on Mars or the Jovan moon, Europa, could provide vital clues.
In many ways, perhaps it has even more relevance as a testimony to the extraor-
dinary biodiversity of this planet and to the enormous potential of its collective
gene pool.
References
Burton, S.G., Cowan, D.A. and Woodley, J.M. (2002) The search for the ideal
biocatalyst, Nature Biotechnology , 20 : 37-45.
Chapelle, F.H., O'Neill, K., Bradley, P.M., Methe, B.A., Ciufo, S.A., Knobel, L.
and Lovley, D.R.A. (2002) A hydrogen-based subsurface microbial community
dominated by methanogens, Nature , 415 : 312-15.
Cui, Y., Wei, Q.Q., Park, H.K., Lieber, C.M.(2001a) Nanowire nanosensors for
highly sensitive and selective detection of biological and chemical species,
Science , 293 : 1289-92.