Will we ever understand? The undescribable diversity of the prokaryotes.

This communication will summarize recent estimations on prokaryotic cell numbers, technical aspects of the exploration of the hidden diversity of the as-yet-uncultured prokaryotes and their function in the environment, recognition of novel major lines of descent, elucidation of novel metabolic pathways and attempts to improve the definition of the taxon species. These are some of recent highlights that will reflect only incompletely recent advances of microbiologist and other aspects of diversity at the genomic level, including the tremendous influence of whole genome sequences on the development of DNA macro- and microarrays for rapid identification of genes and specimen, the annotation of gene sequences to gene function by proteomics and the recognition of the extent of lateral gene transfer in the evolution of the genome, hence of contemporary organisms. As an example of modern trends in systematics three new families will be described for recently described genera, namely Thermoleophilaceae, Solirubrobacteraceae and Conexibacteraceae, which are phylogenetically positioned among environmental clone sequences at the root of the class Actinobacteria.