Lexikon

adaptation is the evolutionary process whereby a population becomes better suited to its habitat. This process takes place over many generations, and is one of the basic phenomena of biology.

The term adaptation may also refer to a feature which is especially important for an organism's survival. Such adaptations are produced in a variable population by the better suited forms reproducing more successfully, that is, by natural selection.

Microorganism, due to their short generation time may succesfully be adapted to new environmental conditions, such as temperature, salinity, nutrient supply, toxic contaminants, etc.

The genom of the microorganisms is very versatile: their adaptive genes, which can be swithched on, when necessary, the frequent mutations and the horizontal gene-transfer between the members of the population and the whole microbial community makes the soil microbes flexible and possible to adapt to the utilisation of new substrates (also soil contaminants) and to become resistant to toxic chemical substances. In the soil biofilms, where microorganism are living strongly realted to each-other, special forms of horizontal gene transfer may exist, and the genes necessary fir survival can be dispersed in the community with the help of mobile genetical elements, such as plasmids, jumping genes, phages, etc.

The adaptive behaviour of the soil microorganisms makes possible to eliminate soil contaminants and prevent Earth from continuously increasing contaminant-concentrations in soils.