ABSTRACT
Two novel bacteria, with an optimum growth temperature of approximately 60 degrees C, were isolated from Lu-shan hot springs in the central region of Taiwan. These isolates were aerobic, thermophilic, halotolerant, pink-pigmented, heterotrophic and resistant to gamma-radiation. Both pleomorphic, short, rod-shaped cells and coccoid cells were observed. Strains LS-286 (= ATCC BAA-452 = BCRC 17198) and LS-293T (= ATCC BAA-406T = BCRC 17173T) represented a novel species of the genus Rubrobacter, according to a phylogenetic analysis of the 16S rRNA gene, DNA-DNA hybridization, biochemical features and fatty acid composition. The name Rubrobacter taiwanensis sp. nov. is proposed for this novel species, with LS-293T as the type strain.
Subject(s)
Actinobacteria/classification , Actinobacteria/isolation & purification , Hot Springs/microbiology , Actinobacteria/physiology , Actinobacteria/radiation effects , Aerobiosis , Bacterial Typing Techniques , DNA, Bacterial/chemistry , DNA, Bacterial/isolation & purification , DNA, Ribosomal/chemistry , DNA, Ribosomal/isolation & purification , Fatty Acids/analysis , Gamma Rays , Genes, rRNA/genetics , Hot Temperature , Molecular Sequence Data , Nucleic Acid Hybridization , Phylogeny , Pigments, Biological/biosynthesis , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Taiwan , Temperature , Water MicrobiologyABSTRACT
Two novel filamentous bacterial isolates, strains WR-30T 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-30T (= ATCC BAA-399T = CCRC 17170T = DSM 14542T); strain WR-220 (= ATCC BAA400 = CCRC 17171 = DSM 14543) is a reference strain.
Subject(s)
Deinococcus/classification , Deinococcus/isolation & purification , Base Composition , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/genetics , Deinococcus/genetics , Deinococcus/metabolism , Fatty Acids/analysis , Fresh Water/microbiology , Hot Temperature , Lipids/analysis , Microscopy, Electron , Molecular Sequence Data , Phenotype , Phylogeny , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Taiwan , Terminology as TopicABSTRACT
Two novel thermophilic bacterial strains, with an optimum growth temperature of between 50 and 60 degrees C, were isolated from the Chi-ban Hot Springs in eastern Taiwan. Strains CB-225 and CB-226(T) were aerobic, thermophilic, non-sporulating, yellow-pigmented heterotrophic organisms. These strains exhibited an unusual denitrification reaction, reducing nitrite, but not nitrate, with the production of N2O only. On the basis of a phylogenetic analysis of 16S rDNA sequences, DNA-DNA similarity data, morphological, physiological and biochemical characteristics, and fatty acid compositions, it was found that the novel strains belonged to the genus Pseudoxanthomonas and represented a novel species within this genus, for which the name Pseudoxanthomonas taiwanensis is proposed; the type strain is CB-226(T) (= ATCC BAA-404(T) = CCRC 17172(T)). P. taiwanensis differs from the only member of the genus Pseudoxanthomonas, the mesophilic species Pseudoxanthomonas broegbernensis, in that it exhibits a higher growth temperature and different morphological characteristics, such as the absence of polar flagella.
