Isolation and characterisation of moderately halophilic bacteriumHalomonas ventosae DL7 synthesizing ectoine as compatible solute
ABSTRACT A moderately halophilic Gram-negative bacterium, strain DL7, was isolated from saltern sediment of Dalian, China. Phylogenetic
analysis based on 16S rRNA gene sequences indicated that this isolate belongs to the genusHalomonas. Based on the taxonomic and DNA sequence in addition to high DNA-DNA homologies, we concluded that this strain was similar
with the type strain ofHalomonas ventosae. Ectoine, one of the representative compatible solutes, was mainly detected in the cells as a result of1H- and13C-NMR measurements when grown in the presence of wide concentration ranges of NaCl. The results showed that higher amount
of ectoine was synthesized in a shorter incubation time compared with those of other strains reported earlier.
- SourceAvailable from: Georg Lentzen[show abstract] [hide abstract]
ABSTRACT: beta-Amyloid peptide (Abeta) is the major constituent of senile plaques, the key pathological feature of Alzheimer's disease. Abeta is physiologically produced as a soluble form, but aggregation of Abeta monomers into oligomers/fibrils causes neurotoxic change of the peptide. In nature, many microorganisms accumulate small molecule chaperones (SMCs) under stressful conditions to prevent the misfolding/denaturation of proteins and to maintain their stability. Hence, it is conceivable that SMCs such as ectoine and hydroxyectoine could be potential inhibitors against the aggregate formation of Alzheimer's Abeta, which has not been studied to date. The current work shows the effectiveness of ectoine and hydroxyectoine on the inhibition of Abeta42 aggregation and toxicity to human neuroblastoma cells. The characterization tools used for this study include thioflavin-T induced fluorescence, atomic force microscopy and cell viability assay. Considering that ectoine and hydroxyectoine are not toxic to cellular environment even at concentrations as high as 100 mM, the results may suggest a basis for the development of ectoines as potential inhibitors associated with neurodegenerative diseases.FEBS Letters 09/2005; 579(21):4775-80. · 3.58 Impact Factor
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ABSTRACT: A moderately halophilic bacterium, strain SS20(T), capable of growing at salinities of 1-20 % (w/v) NaCl was isolated from a solar saltern of the Dangjin area in Korea and was characterized taxonomically. Strain SS20(T) was a Gram-negative bacterium comprising motile, short rods. Its major cellular fatty acids were C(18 : 1)omega7c, C(19 : 0)omega8c cyclo and C(16 : 0). The DNA G+C content was 70 mol% and the predominant ubiquinone was Q-9. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SS20(T) belonged to the genus Halomonas. The levels of 16S rRNA gene sequence similarity to the type strains of Halomonas species were in the range 93.0-97.5 %. The levels of DNA-DNA relatedness between strain SS20(T) and the type strains of phylogenetically closely related Halomonas species were in the range 5.3-12.3 %. On the basis of physiological and molecular properties, strain SS20(T) represents a novel species of the genus Halomonas, for which the name Halomonas koreensis sp. nov. is proposed. The type strain is SS20(T) (=KCTC 12127(T)=JCM 12237(T)).International journal of systematic and evolutionary microbiology 12/2004; 54(Pt 6):2037-42. · 2.11 Impact Factor
- Bioinformatics. 01/2001; 17:1244-1245.