THERMUS-SILVANUS SP-NOV AND THERMUS-CHLIAROPHILUS SP-NOV, 2 NEW SPECIES-RELATED TO THERMUS-RUBER BUT WITH LOWER GROWTH TEMPERATURES

Strains of Thermus silvanus sp, nov, and strains of Thermus chliarophilus sp, nov. were isolated from the hot spring at Vizela in northern Portugal and the hot spring at Alcafache in central Portugal, respectively, The strains of T. silvanus produce orange-red-pigmented colonies and have an optimum growth temperature of about 55 degrees C, while the strains of T. chliarophilus produce yellow-pigmented colonies and have an optimum growth temperature of about 50 degrees C. The strains of both species are catalase negative, These species can be distinguished from each other and from Thermus ruber by biochemical characteristics, fatty acid composition data, and 16S rRNA gene sequence data, Our phylogenetic analysis showed that strains VI-R2(T) (T = type strain) and ALT-8(T) belong to the T, ruber line of descent, The type strain of T, silvanus is strain VI-R2 (= DSM 9946), and the type strain of T. chliarophilus is strain ALT-8 (= DMS 9957).