Cultivation of the “Tough-to-Cultivate”
Approximately 5% of all prokaryotic cells on Earth inhabit the soils worldwide. However, only 0.1 to 1.0 % of all prokaryotic taxa have actually been cultured. Obviously, this unexplored majority has a huge impact on prokaryotic phylogeny, where entire lineages may be missing because of the inability to culture that group in the laboratory.
By using a guided-enrichment strategy that combines molecular tools and conventional microbiological cultivation methods, we are now cultivating bacteria with obligate growth requirements from different soils. Strategies such as the use of soil incubation chambers which simulate the natural environment/microclimate of the growing bacteria have been developed, standardized and used for the cultivation of members of the bacterial phylum Acidobacteria and Verrucomicrobia. We are now purifying these bacterial cultures for further characterization.