Caldalkalibacillus thermarum gen. nov., sp. nov., a novel alkalithermophilic bacterium from a hot spring in China.
ABSTRACT A thermophilic, alkaliphilic and catalase-positive bacterium, designated strain HA6(T), was isolated from a hot spring in China. The strain was aerobic and chemo-organotrophic and grew optimally at 60 degrees C, pH 8.5 and 1.5 % (w/v) NaCl. The cells were Gram-positive rods, forming single terminal endospores. The predominant cellular fatty acids were iso-C(15 : 0) and iso-C(17 : 0). The cell-wall peptidoglycan contained meso-diaminopimelic acid. The genomic DNA G+C content was 45.2 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain HA6(T) formed a distinct lineage within the family Bacillaceae and was most closely related to Bacillus horti K13(T) and Bacillus smithii DSM 4216(T), with sequence similarities of 91.8 and 93.1 %, respectively. On the basis of its physiological and molecular properties, strain HA6(T) should be placed in a novel genus and species, for which the name Caldalkalibacillus thermarum gen. nov., sp. nov. is proposed. The type strain of Caldalkalibacillus thermarum is strain HA6(T) (=CGMCC 1.4242(T)=JCM 13486(T)).
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ABSTRACT: A novel alkaliphilic and moderately halophilic gram-positive coccus, designated strain T8T, was isolated from Baer Soda Lake in Inner Mongolia Autonomous Region, China. Strain T8T grew in the presence of 0-25% (w/v) NaCl and at pH 6.5-11.5, with optimum growth at 10% (w/v) NaCl and pH 9.0. It grew at 10.0-46.0 degrees C, with an optimum growth temperature of 32.0 degrees C. The organism was strictly aerobic, non-motile, non-sporulating and catalase- and oxidase-positive. The DNA G+C content was 49.6 mol%. The cell wall contained Lys and Gly. The major isoprenoid quinone was menaquinone 6 (MK-6). Phylogenetic analyses based on 16S rDNA sequence comparisons indicate that strain T8T is a member of the genus Salinicoccus. DNA-DNA relatedness of less than 50% with the described species of Salinicoccus supported the view that this organism represents a novel species of the genus Salinicoccus. The name Salinicoccus alkaliphilus sp. nov. is proposed for this novel species. The type strain is T8T (= AS 1.2691T = JCM 11311T).International journal of systematic and evolutionary microbiology 06/2002; 52(Pt 3):789-93. · 2.11 Impact Factor
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ABSTRACT: We have developed three computer programs for comparisons of protein and DNA sequences. They can be used to search sequence data bases, evaluate similarity scores, and identify periodic structures based on local sequence similarity. The FASTA program is a more sensitive derivative of the FASTP program, which can be used to search protein or DNA sequence data bases and can compare a protein sequence to a DNA sequence data base by translating the DNA data base as it is searched. FASTA includes an additional step in the calculation of the initial pairwise similarity score that allows multiple regions of similarity to be joined to increase the score of related sequences. The RDF2 program can be used to evaluate the significance of similarity scores using a shuffling method that preserves local sequence composition. The LFASTA program can display all the regions of local similarity between two sequences with scores greater than a threshold, using the same scoring parameters and a similar alignment algorithm; these local similarities can be displayed as a "graphic matrix" plot or as individual alignments. In addition, these programs have been generalized to allow comparison of DNA or protein sequences based on a variety of alternative scoring matrices.Proceedings of the National Academy of Sciences 05/1988; 85(8):2444-8. · 9.74 Impact Factor
Article: Alkalithermophiles.[show abstract] [hide abstract]
ABSTRACT: Alkalithermophiles are an exciting subset of extremophilic organisms and represent extremophiles that are adapted to two extreme conditions, i.e. to a combination of alkaline and thermobiotic growth conditions. Among the anaerobic alkalithermophiles are representatives of both Bacteria and Archaea within a wide variety of physiological types and systematic groups, although a great majority belongs to the Firmicutes. Alkaliphiles have been isolated from a variety of niches including mesobiotic and neutrophilic soils and sediments. Interestingly anaerobic isolates from mesobiotic and neutrophilic niches exhibit shorter doubling times than isolates from thermobiotic niches; some anaerobic alkalithermophiles exhibit extremely fast growth rates, i.e. doubling times as short as 10 min. Their adaptation to both high pH and high temperature draws our attention not only because they are potential sources of industrially valuable enzymes but also because of their adaptive mechanisms to external environmental parameters. They could thus function as model organisms for extraterrestrial life in some environments and for theories on the origin of life. Alkalithermophiles, as far we know, do not represent the most thermophilic nor the most alkaliphilic of micro-organisms but represent the most alkaliphilic ones among the thermophiles and vice versa. We believe that the presently known species are only the tip of the iceberg and therefore that they do not represent the true boundaries under which life can thrive in respect to high temperature in alkaline environments.Biochemical Society Transactions 05/2004; 32(Pt 2):193-8. · 2.59 Impact Factor