All members of the genera Haloarcula and Halomicrobium whose names have been validly published were surveyed for 16S rRNA gene polymorphism, and the transcription of the genes from two species was investigated during growth at different NaCl concentrations. The species of Haloarcula and Halomicrobium harbour at least two different 16S rRNA gene copies, and 18 new sequences of 16S rRNA genes were obtained. The type I and type II 16S rRNA genes of Haloarcula are divergent at 4.8-5.6% of their nucleotide positions. The type III and type IV 16S rRNA genes from Halomicrobium mukohataei JCM 9738(T) are 9.0% divergent, which represents the highest intraspecific divergent 16S rRNA genes so far seen. Phylogenetic analysis based on 16S rRNA genes indicated that all type I 16S rRNA genes were clustered, and the same was true for the type II 16S rRNA genes of Haloarcula species. The two clusters, respectively generated from type I and type II 16S rRNA genes, were sharply separated and their divergences (4.8-5.6%) are in the range of various divergence usually found between genera in the order Halobacteriales (about 5-10%). Results from reverse transcription-PCR showed that the type I and type II copies of Har. amylolytica BD-3(T) and type III and type IV copies of Hmc. mukohataei JCM 9738(T) were all transcribed to 16S rRNA molecules under different salt concentrations (15-28% NaCl).
Two halophilic archaeal strains TBN4(T) and TBN5 were isolated from Taibei marine solar saltern in Jiangsu, China. Both strains showed light red-pigmented colonies and their cells were rod, motile and Gram-stain-negative. They were able to grow at 25-50°C (optimum 37°C), at 1.4-4.3 M NaCl (optimum 2.1 M NaCl), at 0-1.0 M MgCl(2) (optimum 0.005 M MgCl(2)) and at pH 6.0-9.0 (optimum pH 7.0). Their cells lyse in distilled water and minimal NaCl concentration to prevent cell lysis is 8% (w/v). The major polar lipids of the two strains were PG (phosphatidylglycerol), PGP-Me (phosphatidylglycerol phosphate methyl ester), PGS (phosphatidylglycerol sulfate) and five glycolipids chromatographically identical to S-TGD-1 (sulfated galactosyl mannosyl glucosyl diether), S-DGD-1 (sulfated mannosyl glucosyl diether), TGD-1 (galactosyl mannosyl glucosyl diether), DGD-1 (mannosyl glucosyl diether) and DGD-2 (an unknown diglycosyl diether). Phylogenetic analysis revealed that TBN4(T) and strain TBN5 formed a distinct clade with genus Haladaptatus (showing 90.0-90.9% 16S rRNA gene similarities). The DNA G + C content of strain TBN4(T) and strain TBN5 are 66.1 and 65.4 mol%, respectively. The DNA-DNA hybridization value between strain TBN4(T) and strain TBN5 was 94.3%. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strain TBN4(T) and strain TBN5 represent a novel species in a new genus within the family Halobacteriaceae, for which the name Halorussus rarus gen. nov., sp. nov. is proposed. The type strain is TBN4(T) (=CGMCC 1.10122(T) = JCM 16429(T)).
Halophilic archaea represent a promising natural source of carotenoids. However, little information is available about the biological effects of carotenoids from halophilic archaea. In this study, the carotenoids produced by seven halophilic archaeal strains Halogeometricum rufum, Halogeometricum limi, Haladaptatus litoreus, Haloplanus vescus, Halopelagius inordinatus, Halogranum rubrum, and Haloferax volcanii were identified by ultraviolet/visible spectroscopy, thin-layer chromatography, and high-performance liquid chromatography-tandem mass spectrometry. The C carotenoids bacterioruberin and its derivatives monoanhydrobacterioruberin and bisanhydrobacterioruberin were found to be the predominant carotenoids. The antioxidant capacities of the carotenoids from these strains were significantly higher than β-carotene as determined by 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. The antihemolytic activities of these carotenoid extracts against HO-induced hemolysis in mouse erythrocytes were 3.9-6.3 times higher than β-carotene. A dose-dependent in vitro antiproliferative activity against HepG2 cells was observed for the extract from Hgm. limi, while that from Hpn. vescus exhibited a relatively high activity in a dose-independent manner. These results suggested that halophilic archaea could be considered as an alternative source of natural carotenoids with high antioxidant, antihemolytic, and anticancer activity.
bRecent studies have reported high levels of fecal indicator enterococci in marine beach sand. This study aimed to determine the spatial and temporal variation of enterococcal abundance and to evaluate its relationships with microbial community parameters in Hawaii beach sand and water. Sampling at 23 beaches on the Island of Oahu detected higher levels of enterococci in beach foreshore sand than in beach water on a mass unit basis. Subsequent 8-week consecutive samplings at two selected beaches (Waialae and Kualoa) consistently detected significantly higher levels of enterococci in backshore sand than in foreshore/nearshore sand and beach water. Comparison between the abundance of enterococci and the microbial communities showed that enterococci correlated significantly with total Vibrio in all beach zones but less significantly with total bacterial density and Escherichia coli. Samples from the different zones of Waialae beach were sequenced by 16S rRNA gene pyrosequencing to determine the microbial community structure and diversity. The backshore sand had a significantly more diverse community and contained different major bacterial populations than the other beach zones, which corresponded to the spatial distribution pattern of enterococcal abundance. Taken together, multiple lines of evidence support the possibility of enterococci as autochthonous members of the microbial community in Hawaii beach sand.
A convergent, stereocontrolled total synthesis of the architecturally complex tremorgenic indole alkaloid (-)-penitrem D (4) has been achieved. Highlights of the synthesis include an efficient, asymmetric synthesis of the western hemisphere; the stereocontrolled assembly of the I-ring; discovery of a novel autoxidation to introduce the C(22) tertiary hydroxyl group, required for tremorgenic activity; union of fully elaborated eastern and western hemispheres, exploiting an indole synthetic protocol developed expressly for this purpose; and a late-stage, stereoselective construction of the A and F rings exploiting a Sc(OTf)(3-)promoted reaction cascade. The longest linear sequence leading to (-)-penitrem D (4) was 43 steps.
Two Gram-negative, motile, aerobic bacterial strains, designated B2T and 1_C16_27T, were respectively isolated from a seawater sample collected from the East China Sea and a semi-coke sample from north-eastern Estonia. Their genetic, phenotypic and chemotaxonomic properties were studied. The isolates were short rods with polar flagella and were positive for catalase and oxidase activities. Q-10 was the predominant respiratory ubiquinone. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol and two unidentified glycolipids. The major fatty acids were nonadecanoic (C19 : 0 cyclo), octadecanoic (C18 : 0 and C18 : 0 3-OH), octadecenoic (C18 : 1) and hexadecanoic (C16 : 0) acids. The G+C content of the genomic DNA was 58.1–59.3 mol%. 16S rRNA gene sequence analysis revealed that the two isolates represent a distinct lineage within the family Hyphomicrobiaceae. The phylogenetically closest relatives were Cucumibacter (92.7–93.7 % 16S rRNA gene sequence similarity), Devosia (92.9–94.4 %) and Zhangella (91.7–92.1 %). Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strains B2T and 1_C16_27T could be differentiated from each other and from members of the genera Cucumibacter, Devosia and Zhangella. Therefore, it is proposed that strains B2T and 1_C16_27T represent two novel species in a new genus, for which the names Pelagibacterium halotolerans gen. nov., sp. nov. (the type species; type strain B2T = CGMCC 1.7692T = JCM 15775T) and Pelagibacterium luteolum sp. nov. (type strain 1_C16_27T = CGMCC 1.10267T = JCM 16552T = CELMS EEUT 1C1627T) are proposed.
Halolamina pelagica gen. nov., sp. nov., a new member of the family Halobacteriaceae Two extremely halophilic archaeal strains, TBN21 T and TBN49, were isolated from the Taibei marine solar saltern near Lianyungang city, Jiangsu province, China. Cells of the two strains were pleomorphic and Gram-negative and colonies were red. Strains TBN21 T and TBN49 were able to grow at 25-50 6C (optimum 37 6C), at 1.4-5.1 M NaCl (optimum 3.4-3.9 M) and at pH 5.5-9.5 (optimum pH 7.0-7.5) and neither strain required Mg 2+ for growth. Cells lysed in distilled water and the minimal NaCl concentration to prevent cell lysis was 8 % (w/v). The major polar lipids of the two strains were phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate and eight glycolipids; three of these glycolipids (GL3, GL4 and GL5) were chromatographically identical to sulfated mannosyl glucosyl diether (S-DGD-1), galactosyl mannosyl glucosyl diether (TGD-1) and mannosyl glucosyl diether (DGD-1), respectively. The past 5 years have witnessed the rapid expansion of the family Halobacteriaceae, the single family described within the order Halobacteriales. As many novel species have been discovered and added to established genera (Oren et al. et al., 2011). This expansion indicates that the family Halobacteriaceae is more diverse than was previously recognized. During our surveys of the halophilic archaeal diversity of marine solar salterns of eastern China, we isolated two pleomorphic, thin-slice-shaped strains that were phylogenetically related to Halobaculum (Hbl.) gomorrense Oren et al. 1995 (89.0-89.5 % 16S rRNA gene sequence similarity to the type strain). In this study, we characterize these two strains as representing a novel species in a new genus of the family Halobacteriaceae. Strains TBN21T and TBN49 were isolated from brine sampled from Taibei
Two extremely halophilic archaea, strains RO2-11(T) and HO2-1, were isolated from two Chinese marine solar salterns, Rudong solar saltern and Haimen solar saltern, respectively. Cells of the two strains were polymorphic and Gram-stain-negative; colonies were red-pigmented. The two strains grew at NaCl concentrations of 2.6-4.3 M (optimum 3.9 M) and required at least 0.1 M Mg2+ for growth. They were able to grow over a pH range of 6.0-8.0 and a temperature range of 20-50 degrees C, with optimal pH of 7.5 and optimal temperature of 37 degrees C. The major polar lipids of strain RO2-11(T) and strain HO2-1 were phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and three glycolipids, two of them chromatographically identical to S-DGD-1 and DGD-1, the third unidentified. The 16S rRNA gene sequence similarity of strain RO2-11(T) and strain HO2-1 was 99.3 % and highest sequence similarity with the closest relative (Haloferax larsenii) was 91.4 %. Based on the data obtained, the two isolates could not be classified in any recognized genus of the family Halobacteriaceae. Strain RO2-11(T) and strain HO2-1 are thus considered to represent a novel species of a new genus within the family Halobacteriaceae, for which the name Halogranum rubrum gen. nov., sp. nov. is proposed. The type strain is RO2-11(T) (=CGMCC 1.7738(T) =JCM 15772(T)).
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