A molecular view of archaeal diversity in marine and terrestrial hot waterenvironments

Molecular phylogenetic survey of naturally occurring archaeal diversities i n hot water environments was carried out by using the PCR-mediated small su bunit rRNA gene (SSU rDNA) sequencing. Mixed population DNA was directly ex tracted from the effluent hot water or sediment of a shallow marine hydroth ermal vent at Tachibana Bay, or the acidic hot water of hot spring pools at Mt. Unzen, in Nagasaki Prefecture, Japan. Based on the partial rDNA sequen ces amplified with an Archaea-specific primer set, the archaeal populations of hot water environments consisted of phylogenetically and physiologicall y diverse group of microorganisms. The archaeal populations were varied in each sample and subject to its environmental conditions. In addition, the l arge number of archaeal rDNA sequences recovered from hot water environment s revealed the distant relationship not only to the rDNA sequences of the c ultivated thermophilic archaea, but also to the sequences of unidentified a rchaeal rDNA clones found in other hot water environments. The findings ext end our view of archaeal diversity in hot water environments and phylogenet ic organization of these organisms. (C) 1999 Federation of European Microbi ological Societies. Published by Elsevier Science B.V. All rights reserved.