Halanaerobacter jeridensis sp. nov., isolated from a hypersaline lake.
ABSTRACT An obligatory anaerobic, moderately halophilic bacterium, designated strain CEJFG43(T), was isolated from a sample of sediment collected below the salt crust on the hypersaline El Jerid lake, in southern Tunisia. The cells of this novel strain were Gram-staining-negative, non-sporulating, motile, short rods. They grew in media with 6-30% (w/v) NaCl (optimum 15%), at 20-60 °C (optimum 45 °C) and at pH 5.5-9.5 (optimum pH 8.3). The micro-organism fermented glucose, fructose, ribose, raffinose, galactose, mannose, sucrose, maltose, xylose, mannitol, pyruvate and glycerol. The products of glucose fermentation were lactate, ethanol, acetate, H(2) and CO(2). The genomic G+C DNA content of strain CEJFG43(T) was 33.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CEJFG43(T) belonged in the genus Halanaerobacter and was most closely related to Halanaerobacter lacunarum DSM 6640(T) (95.3% gene sequence similarity) and Halanaerobacter chitinivorans DSM 9569(T) (95.3%). The predominant cellular fatty acids were non-branched (C(16:0) and C(16:1)). Based on the phylogenetic and phenotypic evidence, strain CEJFG43(T) represents a novel species in the genus Halanaerobacter for which the name Halanaerobacter jeridensis sp. nov. is proposed. The type strain is CEJFG43(T) ( = DSM 23230(T) = JCM 16696(T)).
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ABSTRACT: Two halophilic anaerobic bacteria, one of which had chitinolytic activity, were isolated from a solar saltern in southern California. These organisms were long, gram-negative, motile, flexible rods. The biochemical and physiological characteristics of these bacteria were very similar but were different from the characteristics of other haloanaerobic bacteria. Both grew at salt concentrations ranging from 0.5 to 5 M and at temperatures ranging from 23 to 50 degrees C. They were sensitive to chloramphenicol but resistant to penicillin, carbenicillin, d-cycloserine, streptomycin, and tetracycline. An analysis of DNAs and whole-cell proteins showed that they were closely related taxonomically and distinguishable from other halophilic anaerobic bacteria. They exhibited 92.3 to 100% DNA homology as determined by DNA-DNA hybridization. The guanine-plus-cytosine contents of their DNAs were 34.8+/-1 mol%. The two isolates, strains W5C8 and W3C1, differed from other halophilic anaerobic bacteria sufficiently to support establishment of a new genus and species, Haloanaerobacter chitinovorans. Strain W5C8 exhibited chitinolytic activity and is designated the type strain. Two chitin-induced extracellular proteins with molecular weights of 38 x 10 and 40 x 10 were detected in strain W5C8.Applied and Environmental Microbiology 02/1992; 58(1):260-6. · 3.95 Impact Factor
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ABSTRACT: A novel halophilic fermentative bacterium has been isolated from the black sediment below a gypsum crust and a microbial mat in hypersaline ponds of Mediterranean salterns. Morphologically, physiologically and genetically this organism belongs to the genus Haloanaerobacter. Haloanaerobacter strain SG 3903T (T = type strain) is composed of non-sporulating long flexible rods with peritrichous flagella, able to grow in the salinity range of 5-30% NaCl, with an optimum at 14-15%. The strain grows by fermenting carbohydrates or by using the Stickland reaction with either serine or H2 as electron donors and glycine-betaine as acceptor, which is reduced to trimethylamine. The two species described so far in the genus Haloanaerobacter are not capable of Stickland reaction with glycine-betaine + serine; however, Haloanaerobacter chitinovorans can use glycine-betaine with H2 as electron donor. Strain SG 3903T thus represents the first described strain in the genus Haloanaerobacter capable of the Stickland reaction with two amino acids. Although strain SG 3903T showed 67% DNA-DNA relatedness to H. chitinovorans, it is physiologically sufficiently different from the two described species to be considered as a new species which has been named Haloanaerobacter salinarius sp. nov.International journal of systematic bacteriology 02/1999; 49 Pt 1:103-12. · 2.27 Impact Factor
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ABSTRACT: Dunaliella parva, a green halophilic alga, was found to accumulate very large amounts of intracellular glycerol. Through measurements of the intracellular volume the internal concentration of glycerol was calculated and found to be around 2.1 m in cells cultured in 1.5 m NaCl. When the extracellular salt concentration of an algal suspension was increased or decreased, the intracellular glycerol varied accordingly, reaching its new osmotic equilibrium after about 90 minutes. Since no leakage of intracellular glycerol was observed above 0.6 m NaCl, these alterations in glycerol content are interpreted as due to metabolic formation and degradation of intracellular glycerol. The above results indicate the existence of a new type of algal osmoregulation, in which the osmotic balance depends on the synthesis or degradation of intracellular glycerol in response to the external salt concentration.Plant physiology 06/1973; 51(5):875-8. · 6.56 Impact Factor