Genomic sequence of hyperthermophile, Pyrococcus furiosus: implications for physiology and enzymology.

Publisher Summary Microorganisms that are able to grow at temperatures above 90° are called as “hyperthermophiles.” They form a diverse group consisting of autotrophic and heterotrophic prokaryotes, including several bacteria, although the majority of hyperthermophiles are Archaea. Most of the conventional tools of genetic and physiological analysis are either not effective or very difficult to apply to these microorganisms because of their unusual growth conditions. As a result, relatively slow progress has characterized the field since its inception. A new paradigm has characterized the field recently, with the availability of complete genome sequences of five hyperthermophiles. A unique resource for comparative studies of hyperthermophiles—namely, the complete genomic sequences of three species in the genus Pyrococcus, is now accessible. Although these strains are quite similar in their fermentative, sulfur-reducing growth physiology and optimal growth temperatures, which are in the range 98-100°, significant issues of genome divergence are emerging from the ongoing study of their genomic sequences.