Abstract
Two novel filamentous bacterial isolates, strains WR-30(T) and WR-220, with an optimum growth temperature of approximately 55--60 degrees C were isolated from Wu-rai hot springs in the northern part of Taiwan. These isolates were aerobic, thermophilic, non-sporulating, red-pigmented and heterotrophic and formed extremely long, filamentous trichomes from cells of different lengths. Phylogenetic analysis of 16S rDNA, DNA--DNA hybridization, morphological and biochemical features and fatty acid composition revealed that the isolates represent a novel species of the genus Meiothermus. The name Meiothermus taiwanensis sp. nov. is proposed for this novel species. The type strain of M. taiwanensis is strain WR-30(T) (=ATCC BAA-399(T)=CCRC 17170(T)=DSM 14542(T)); strain WR-220 (=ATCC BAA-400=CCRC 17171=DSM 14543) is a reference strain.