Download Adaptation of microorganisms to extreme environments

FEMS MicrobiologyReviews75 (1990) 103, 104
Publishedby Elsevier
103
FEMSRE00151
Editorial
Adaptation of microorganisms to extreme environments
R.A. Prins, W. de Vrij, J.C. Gottschal and Th.A. Hansen
A workshop under the above title was held in
June 1989 at the Biological Centre in Haren of the
University of Groningen, The Netherlands. The
workshop was organized by the Royal Netherlands Academy ol Arts and Sciences (Biology
Council) and the Department of Microbiology zr
Haren and sponsored by the biotechnology industry, various scientific foundations and the Ur~ivcrsity of Groningen. All participants were invited
on the basis of their interest and active research in
the field of 'extremophiles'.
Our knowledge of biology in the past has largely
been determined by the results of research on
organisms living and functioning in environments
characterized by moderate physieo-ehemieal prc,perties. An anthropocentric approach is the basis
for the contents of the term 'moderate'. Temperature, heavy metal concentrations, contents of salts
and nutrients, pH, pressure oxygen and water
concentrations of the habitats studied were most
often in a range considered 'normal' for living
organisms. A considerable part of our insight in
the functioning of the cell has been based on
observations of cells functioning optimally at a
pressure of 1 arm, at near neutral pH, and in an
isotonic solution having a temperature of 30370C.
Recently, microorganisms have been discovered
that appear to live in habitats which can be considered as extreme on the basis of the prevailing
environmental conditions. At an increased rate
such microorganisms are isolated from the most
diverse and bizarre environments: hot deserts,
frozen soils and rocks in the ~'alleys of Antarctica,
hot sulphurous springs on Iceland, Italian solfatao
ras, the deep sea with its cold seeps and black
smokers, alkaline lakes in Egypt and Central
Africa, extremely acidic environments like the
seepage of ores and mine-refuse piles, natural salt
lakes, artificial saltpans or even salt crystals in
which microorganisms have been trapped for some
200 w2llion years.
Throughout such studies it has repeatedly been
demonstrated that the boundaries and borderlines
in our thinking about the conditions which allow
life on earth have to be enlarged. Not only are
these organisms found in places often considered
empty in the biological sense, it also is clear that
these microbes have developed numerous special
adaptations to survive in extreme habitats. Among
these adaptations are: new mechanisms for energy
transduction and for the regulation of the intracellular environment and metabolism, new biochemical answers to problems concerning the stability of structural and functional components of
the cell membrane and the cell wall or concerning
the functioning of coenzymes. The results of research on these themes are of considerable importance to microbiology as well as to biology in
general.
New and highly original techniques are also
needed to study the "extremophiles'. Experimental
procedures during sampling, culturing, choice of
materials and preparatory techniques often are as
extreme as the habitats studied. Another aspect of
this field is its obvious multidisciplinary character
as the studies call for a permanent dialogue between microbiologists, geoehemists, biochemists
and physicists. A further deepening of biological
research on extremophilic organisms is of particular importance for our understanding of the eady
evolution of prokaryotes, the relation between
0168-6445/90/$03.50 © t990 Federationof European MicrobiologicalSocieties
104
structure and function of cell components and
enzymes, the evolution of survival strategies,
mechanisms of energy transduction and conservation, while its significance for biotcchnology is
thought to be enormous.
In the seven sessions of the workshop (thermophiles, general adaptive properties of thermophiles, biochemistry of thermophiles, osmoregulation, alkaliphiles, acidophiles, and applications),
twenty-two invited speakers reviewed their re-
search results and presented an overview of the
present knowlegde in their field of interest as
introductions to the discussions. Some forty posters were ~resented.
The organizers are grateful to Professor G.
Gottschalk, the Editor-in-Chief of FEMS Microbiology Reviews, for his offer to publish the
manuscripts of most of the introductory lectures
of the workshop in this journal.