Uncultivated Microorganisms

The number of existing microbial species may be in the millions, but only a few thousand have been isolated in pure culture and described. The principal reason for this tremendous disparity is that, mysteriously, over 99% of all environmental microorganisms refuse to grow in the laboratory. The phenomenon of microbial uncultivability has been recognized as one of the main challenges for basic and applied microbiology, and finding a way to access this uncultivated microbial majority may change many aspects of biology and biotechnology as we know them today.

This volume describes the discovery of the phenomenon, the current hypotheses on its physiological and molecular nature, state-of-the-art approaches to "outsmarting" the uncultivated microorganisms, and the importance of the uncultivated microbial majority in medicine and biotechnology. It reveals the hidden universe of uncultivated microorganisms, their unparalleled diversity and enormous potential for application.

Résumé
In 1898, an Austrian microbiologist Heinrich Winterberg made a curious observation: the number of microbial cells in his samples did not match the number of colonies formed on nutrient media (Winterberg 1898). About a decade later, J. Amann qu- tified this mismatch, which turned out to be surprisingly large, with non-growing cells outnumbering the cultivable ones almost 150 times (Amann 1911). These papers signify some of the earliest steps towards the discovery of an important phenomenon known today as the Great Plate Count Anomaly (Staley and Konopka 1985). Note how early in the history of microbiology these steps were taken. Detecting the Anomaly almost certainly required the Plate. If so, then the period from 1881 to 1887, the years when Robert Koch and Petri introduced their key inventions (Koch 1881; Petri 1887), sets the earliest boundary for the discovery, which is remarkably close to the 1898 observations by H. Winterberg. Celebrating its 111th anniversary, the Great Plate Count Anomaly today is arguably the oldest unresolved microbiological phenomenon. In the years to follow, the Anomaly was repeatedly confirmed by all microb- logists who cared to compare the cell count in the inoculum to the colony count in the Petri dish (cf., Cholodny 1929; Butkevich 1932; Butkevich and Butkevich 1936). By mid-century, the remarkable difference between the two counts became a universally recognized phenomenon, acknowledged by several classics of the time (Waksman and Hotchkiss 1937; ZoBell 1946; Jannasch and Jones 1959).

Contenu
Viable but Not Cultivable Bacteria.- General Model of Microbial Uncultivability.- Statistical Estimation of Uncultivated Microbial Diversity.- Detection and Characterization of Uncultivated Microorganisms Using Microarrays.- Persisters, Biofilms, and the Problem of Cultivability.- Metagenomics and Antibiotic Discovery from Uncultivated Bacteria.- Taking the Concept to the Limit: Uncultivable Bacteria and Astrobiology.- Single Cell Whole Genome Amplification of Uncultivated Organisms.- Physiological and Ecological Adaptations of Slow-Growing, Heterotrophic Microbes and Consequences for Cultivation.- Characterizing Microbial Population Structures through Massively Parallel Sequencing.- The Seabed as Natural Laboratory: Lessons From Uncultivated Methanotrophs.