Extracellular Nucleic Acids of the Marine Phototrophic Bacterium Rhodovulum sulfidophilum and Related Bacteria: Physiology and Biotechnology

Abstract

Extracellular nucleic acids of high molecular weight are present ubiquitously throughout the environment, such as seawater and soil. These nucleic acids were formerly thought to be derived from cells by cell death, but recent studies have shown that they are at least partly derived from the active release of nucleic acids from some bacterial cells. Marine phototrophic bacteria, Rhodovulum sulfidophilum and Rhodovulum sp. strain PS88, produce extracellular nucleic acids and form flocs, i.e., structured communities of cells. This chapter describes highly efficient extracellular nucleic acid production of Rhodovulum sp. strain PS88 and the physiological relationships between extracellular nucleic acids and flocculation in Rdv. sulfidophilum. The structures of extracellular soluble DNA and RNA of Rdv. sulfidophilum are also described. Moreover, proposals for application of these properties to industrial productions of nucleotides and RNA drugs are discussed.