THE PHYLOGENETIC POSITION OF THE THERMOCOCCUS ISOLATE AN1 BASED ON 16S RIBOSOMAL-RNA GENE SEQUENCE-ANALYSIS - A PROPOSAL THAT AN1 REPRESENTS A NEW SPECIES, THERMOCOCCUS-ZILLIGII SP-NOV

The 16S rRNA gene from the Thermococcus New Zealand isolate AN1 was cl oned and sequenced. Analysis of the gene revealed the presence of sign ature sequences, indicating that strain AN1 represents a new species o f the genus Thermococcus. Since the isolate AN1 differed from other th ermococci in both its lower optimal NaCl concentration and generally l ower optimal temperature for growth, in its unusual lipid membrane com position, and in its sensitivity to antibiotics, we propose that strai n AN1 represents a new species of Thermococcus. The proposed name is T hermococcus zilligii, and the type strain is DSM 2770.