A novel extremely halophilic archaeon was isolated from Lake Tebenquiche, situated in the northern part of the Atacama Saltern, Chile. The cells of these micro-organisms were mostly irregularly disc-shaped. They grew in medium containing saturated concentrations of NaCl and did not require magnesium for optimal growth. The polar lipid composition revealed the presence of mannosyl-2-sulfate-(1-4)-glycosyl-archaeol, the main glycolipid of the genus Halorubrum, and two new glycolipids. The GMC content of the DNA was 63 2 mol %. Phylogenetic analysis of the 16S rRNA gene placed strain ALT6-92 T within the Halorubrum cluster. The low DNA-DNA hybridization value justified classification in a new species for which the name Halorubrum tebenquichense sp. nov. is proposed. The type strain is ALT6-92 T (l CECT 5317 T l DSM 14210 T ).

Endospore-forming strains were isolated from corn-compost treated with olive-mill wastewater (' alpechı! n '). The strains were taxonomically studied and proposed as a novel Paenibacillus species. These organisms (strains B.3 T , B.7 and B.9) were particularly distinguishable from other aerobic spore-forming species by their ability to grow optimally in 100 % (v/v) olive-mill wastewater at 30 SC and pH 70 and concomitant production of an interesting exopolysaccharide. Chemotaxonomic analysis revealed that MK-7 was the predominant menaquinone, the major fatty acid was anteiso C 15 :0 and the cell wall contained meso-diaminopimelic acid. The DNA GMC content was 407 mol %. Comparative sequence analysis of 16S rDNA with different reference species from the genera Bacillus, Paenibacillus, Brevibacillus, Aneurinibacillus, Alicyclobacillus, Halobacillus, Virgibacillus, Amphibacillus, Coprobacillus and Gracilibacillus indicated that the isolated strains were highly related to the genus Paenibacillus. Strain B.3 T formed an evolutionary lineage distinct from other species within the evolutionary radiation encompassing the genus Paenibacillus. Strain B.3 T was a close relative of Paenibacillus polymyxa, but DNA-DNA relatedness data with this species was very low (relative binding ratio T 16 %). Based on the morphological and physiological characteristics, as well as on the phylogenetic position determined by 16S rDNA analysis and DNA-DNA relatedness data, it is concluded that these strains should be designated a novel species, for which the name Paenibacillus jamilae sp. nov. is proposed. The type strain is B.3 T (l CECT 5266 T l DSM 13815 T ).

A large number of halophilic bacteria were isolated in 1984-1992 from the Atacama Saltern (North of Chile). For this study 82 strains of extreme halophilic archaea were selected. The characterization was performed by using the phenotypic characters including morphological, physiological, biochemical, nutritional and antimicrobial susceptibility test. The results, together with those from reference strains, were subjected to numerical analysis, using the Simple Matching (S(SM)) coefficient and clustered by the unweighted pair group method of association (UPGMA). Fifteen phena were obtained at an 70% similarity level. The results obtained reveal a high diversity among the halophilic archaea isolated. Representative strains from the phena were chosen to determine their DNA base composition and the percentage of DNA-DNA similarity compared to reference strains. The 16S rRNA studies showed that some of these strains constitutes a new taxa of extreme halophilic archaea.

Two extremely halophilic archaea, strains T and K-1, were isolated from Lake Tebenquiche (Atacama Saltern, Chile) and Ezzemoul sabkha (Algeria), respectively. Cells of the two strains were short-rod-shaped and Gram-negative; colonies were orange-pigmented. They grew optimally at 37-40 6C and pH 7.0-7.5 in the presence of 25 % (w/v) NaCl. Magnesium was not required. Polar lipid analysis revealed the presence of phosphatidylglycerol and phosphatidylglycerophosphate methyl ester, the absence of phosphatidylglycerosulfate, and the presence of sulfated diglycosyl diether and diether diglycosyl as the sole glycolipids. DNA G+C contents of strains Al-5 T and K-1 were 52.4 and 52.9 mol% (T m method), respectively. 16S rRNA gene sequence comparison with database sequences showed that strains Al-5 T and K-1 were most closely related to Halomicrobium mukohataei DSM 12286 T (similarities of 97.5 and 96.9 %, respectively). DNA-DNA hybridization indicated that strains Al-5 T and K-1 were members of a single species. However, DNA-DNA relatedness to Halomicrobium mukohataei was 55.7±2.5 %. A comparative analysis of phenotypic characteristics and DNA-DNA hybridization between the isolates and Halomicrobium mukohataei DSM 12286 T supported the conclusion that Al-5 T and K-1 represent a novel species within the genus Halomicrobium, for which the name Halomicrobium katesii sp. nov. is proposed. The type strain is Al-5 T (5CECT 7257 T 5DSM T).The extremely halophilic archaea are found in hypersaline environments such as the Dead Sea, the Great Salt Lake, sabkhas and natural and artificial salterns. They are classified within the family Halobacteriaceae. Halobacteria are considered to be the most extremely halophilic microorganisms and require at least 1.5 M NaCl for their growth (Grant et al., 2001). Currently, members of the aerobic, extremely halophilic archaea are classified in 26 genera: The genus Halomicrobium was proposed by Oren et al. (2002) and currently contains only one species, Halomicrobium mukohataei, which was first isolated from the soils of the Argentine salt flats (Ihara et al., 1997). In this study, the characterization of two halophilic strains that represent a novel species of the genus Halomicrobium is described.Strain Al-5 T was isolated from Lake Tebenquiche of the Atacama Saltern, Chile, and strain K-1 was isolated from water samples collected from Ezzemoul sabkha located in the north-east of Algeria. They were isolated independently from each other on hypersaline agar medium containing (per litre): 5 g proteose-peptone no. 5 (Difco), 5 g yeast extract (Difco), 1 g glucose with 25 % (w/v) total salts. The stock of total salts at 30 % (w/v) was prepared as described by Subov (1931): 234 g NaCl, 42 g MgCl 2 . 6H 2 O, 60 g MgSO 4 . 7H 2 O, 1 g CaCl 2 . 2H 2 O, 6 g KCl, 0.2 g NaHCO 3 , 0.7 g NaBr, 0.005 g FeCl 3 and 1000 ml distilled water. The medium was brought to pH 7.0 and incubation was at 40 u C. Phenotypic tests of strains T and K-1 were performed according to the proposed minimal standards for the desc...

Haloarchaea are extreme halophilic microorganisms belonging to the domain Archaea, phylum Euryarchaeota, and are producers of interesting antioxidant carotenoid compounds. In this study, four new strains of Haloarcula sp., isolated from saline lakes of the Atacama Desert, are reported and studied by high-resolution mass spectrometry (UHPLC-Q-Orbitrap-MS/MS) for the first time. In addition, determination of the carotenoid pigment profile from the new strains of Haloarcula sp., plus two strains of Halorubrum tebenquichense, and their antioxidant activity by means of several methods is reported. The effect of biomass on cellular viability in skin cell lines was also evaluated by MTT assay. The cholinesterase inhibition capacity of six haloarchaea (Haloarcula sp. ALT-23; Haloarcula sp. TeSe-41; Haloarcula sp. TeSe-51; Haloarcula sp. Te Se-89 and Halorubrum tebenquichense strains TeSe-85 and Te Se-86) is also reported for the first time. AChE inhibition IC50 was 2.96 ± 0.08 mg/mL and BuChE inhibition IC50 was 2.39 ± 0.09 mg/mL for the most active strain, Halorubrum tebenquichense Te Se-85, respectively, which is more active in BuCHe than that of the standard galantamine. Docking calculation showed that carotenoids can exert their inhibitory activity fitting into the enzyme pocket by their halves, in the presence of cholinesterase dimers.

A total of 52 strains of moderately halophilic bacteria isolated from hypersaline sediment of Lake Tebenquiche on the Atacama Saltern, Chile, were subjected to a taxonomic study. The morphological, physiological, biochemical and nutritional characteristics of the strains matched those described for the genus Chromohalobacter. Cells were Gram-negative, non-spore-forming, rod-shaped and motile. A black pigmentation was produced. One strain, designated LTS-4NT, grew optimally at 32 °C. Growth occurred in media containing 0·5–25 % (w/v) total salts; the optimum was 7·5 % (w/v) total salts. The pH range for growth was 5–10. The G+C content of the DNA of strain LTS-4NT was 59·8 mol%. Analysis of 16S rRNA gene sequence similarity revealed that strain LTS-4NT was closely related to Chromohalobacter species; however, DNA–DNA hybridization of representative strain LTS-4NT failed to associate the strain with any species of the genus Chromohalobacter with validly published names. Therefore, the name Chromohalobacter nigrandesensis sp. nov. is proposed. The type strain is LTS-4NT (=CECT 5315T=DSM 14323T).

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The correct name of the type strain of Chromohalobacter nigrandesensis is LTS-4N (as given in the summary), not LST-4N as given in the species description.