General Model of Microbial Uncultivability

Abstract

It has been known for over a century that only a small percent of cells from environmental samples form colonies on standard media (Great Plate Count Anomaly, Staley and Konopka (Annu Rev Microbiol 39:321–346, 1985). This chapter focuses on the causes of this disparity, and describes new cultivation technologies aiming to close the gap. It summarizes the original and literature data on the biology of “uncultivable” species\uncultivable\ species is summarized, and the nature of the restrictions likely limiting the growth of these species is discussed. This analysis leads to a novel model of the microbial life cycle in nature, termed the “scout model.” We argue that if microbial behavior in vivo conforms to the scout model, this will by necessity manifest itself in vitro as the Great Plate Count Anomaly. The scout model also draws connections to other aspects of microbial behavior, such as viability – but not cultivability – of some cells, an apparent slow growth of certain species, seeming ability of microbes to persist in the presence of unfavorable factors, including antibiotics, and latent infections.