Performance of Biodegradative Microorganisms in Soil: Xenobiotic Chemicals as Unexploited Metabolic Niches

Abstract

Microorganisms are where they are because there is a food source or a metabolic niche to exploit. The word “niche,” as derived from the old French nicher (i.e., “to nest”), has been synonymous in rnacroecology to location or habitat. In microbial ecology, niche refers to function rather than location. This is particularly significant with respect to bacteria, since the basic principle of nutritional selection has been used for isolating them from soil since the time of Beijerinck and Winogradsky a century ago. Reduced to basic simplicity, nutrition is the single most powerful selection force in microbial ecology in the absence of extreme environments. The microorganisms that are the best fitted for exploiting the metabolic niches of the environment are the ones that comprise the microbial community in accordance with Darwinian principles of natural selection. Thus, cellulitic fungi and proteolytic bacteria co-exist side by side spatially, while exploiting different niches, and can be isolated exclusively from each other on different selective media. The vast diversity of metabolic niches ranges in simplicity from ammonium to large, uncharacterized macromolecules.