Recent advances in genetic analyses of hyperthermophilic archaea and bacteria.

Hyperthermophilic Archaea and Bacteria are an extraordinarily important class of organisms for which genetic tools remain to be developed. Unique technological obstacles to this goal are posed by the thermophilic and, in some cases, strictly anaerobic nature of these organisms. However, recent advances in the cultivation of hyperthermophiles, in the discovery of genetic elements for vector development, and in the construction of genetic markers point toward the achievement of this goal in the near future. Transformation protocols have already been reported for Sulfolobus and Pyrococcus, and plasmid-mediated conjugation was recently found in Sulfolobus. Plasmids are available for Sulfolobus, Pyrococcus, and the bacterial hyperthermophile Thermotoga, and these provide the bases for vector construction in these hosts. A Desulfurococcus mobile intron may provide a novel means to introduce genes into a variety of archaeal hosts. With full genome sequences of several hyperthermophiles available soon, genetic tools will allow full exploitation of this information to study these organisms in depth and to utilize their unique properties in biotechnological applications.