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3 The Isolation of Thermophiles from Deep-sea Hydrothermal Environments
Satoshi Nakagawa and KenTakai Subground Animalcule Retrieval (SUGAR) Program, Extremobiosphere Research Center, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2^15 Natsushima-cho,Yokosuka 237- 0061, Japan ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
CONTENTS Introduction Sample collection Sample processing and preservation Media Cultivation conditions Isolation Concluding remarks and perspectives
^^^^^ INTRODUCTION The discovery of deep-sea hydrothermal vents in the Mid-Ocean Ridges (Spiess and RISE group, 1980) revolutionized microbiology in the deepsea. Before the discovery, the deep-sea had been simply regarded as a cold, high-pressure, ‘‘desert-like’’ environment, but now physicochemically diverse, nutrient-rich, and biologically productive habitats emerged to the microbiologists. Over 60 different thermophilic and hyperthermophilic species with a variety of physiological characteristics have so far been isolated in pure culture from deep-sea hydrothermal environments. In addition, recent studies using culture-independent approaches have provided the growing consensus that these extreme environments still harbor a diversity of yet-uncultivated microorganisms, some of which are definitely involved in the biogeochemical processes in situ (Huber et al., 2003; Nakagawa et al., 2005b; Nercessian et al., 2003; Reysenbach et al., 2000; Schrenk et al., 2003; Takai and Horikoshi, 1999; Teske et al., 2002). Consequently, the ecology and physiology of yet-uncultivated microorganisms in the deep-sea hydrothermal environments are of particular interest. The importance of cultivation-dependent studies is increasingly recognized since the cellular and molecular basis of the physiology of METHODS IN MICROBIOLOGY, VOLUME 35 0580-9517 DOI:10.1016/S0580-9517(05)35003-3
Copyright ß 2006 Elsevier Ltd. All rights reserved.
Hydrothermal Environments
3 The Isolation of Thermophiles from Deep-sea Hydrothermal Environments
CONTENTS Introduction Sample collection Sample processing and preservation Media Cultivation conditions Isolation Concluding remarks and perspectives
^^^^^ INTRODUCTION The discovery of deep-sea hydrothermal vents in the Mid-Ocean Ridges (Spiess and RISE group, 1980) revolutionized microbiology in the deepsea. Before the discovery, the deep-sea had been simply regarded as a cold, high-pressure, ‘‘desert-like’’ environment, but now physicochemically diverse, nutrient-rich, and biologically productive habitats emerged to the microbiologists. Over 60 different thermophilic and hyperthermophilic species with a variety of physiological characteristics have so far been isolated in pure culture from deep-sea hydrothermal environments. In addition, recent studies using culture-independent approaches have provided the growing consensus that these extreme environments still harbor a diversity of yet-uncultivated microorganisms, some of which are definitely involved in the biogeochemical processes in situ (Huber et al., 2003; Nakagawa et al., 2005b; Nercessian et al., 2003; Reysenbach et al., 2000; Schrenk et al., 2003; Takai and Horikoshi, 1999; Teske et al., 2002). Consequently, the ecology and physiology of yet-uncultivated microorganisms in the deep-sea hydrothermal environments are of particular interest. The importance of cultivation-dependent studies is increasingly recognized since the cellular and molecular basis of the physiology of METHODS IN MICROBIOLOGY, VOLUME 35 0580-9517 DOI:10.1016/S0580-9517(05)35003-3
Copyright ß 2006 Elsevier Ltd. All rights reserved.
Hydrothermal Environments
3 The Isolation of Thermophiles from Deep-sea Hydrothermal Environments