Halobellus rufus sp. nov., an extremely halophilic archaeon isolated from non-purified solar salt

Genome-based classification of Halobellus rubicundus sp. nov., a novel extremely halophilic archaeon isolated from a Korean solar saltern

A novel extremely halophilic archaeon designated, MBLA0158T, was isolated from a solar saltern in Sorae, Republic of Korea. The colonies are red-pigmented, Gram-stain-negative, pleomorphic, non-motile, and lysed in distilled water. The strain grows at 25-45 °C (optimum, 37 °C), in 15-30% (w/v) NaCl (optimum, 20%) and 0.1-1.0 M Mg2+ (optimum, 0.2-0.3 M) at pH 6.0-10.0 (optimum, 7.0-8.0). Comparative analysis based on the 16S rRNA gene sequence revealed that this strain is most closely related to the Halobellus inordinatus YC20T with a sequence identity of 96.0%. Strain MBLA0158T contained phosphatidylglycerol and phosphatidylglycerol phosphate methyl ester as major polar lipids. The genome size is 3.29 Mb and the DNA G + C content is 66.9 mol%. Phylogenomic analysis confirmed that strain MBLA0158T is distinct from previously reported type strains of the genus Halobellus. Pan-genome analysis showed that strain MBLA0158T contains 419 genes that are not present in other type strains of the genus Halobellus. Based on overall analyses, strain MBLA0158T is considered to represent a new species of the genus Halobellus, for which the name Halobellus rubicundus sp. nov. is proposed. The type strain is MBLA0158T (= KCTC 4318T = JCM 36642T).

Halobellus ruber sp. nov., a deep red-pigmented extremely halophilic archaeon isolated from a Korean solar saltern

A novel halophilic archaeon, strain MBLA0160^T, was isolated from a solar saltern in Sorae, Republic of Korea. The cells are deep-red pigmented, Gram-negative, rod shaped, motile, and lysed in distilled water. The strain MBLA0160^T grew at 25-45 °C (optimum 37 °C), in 15-30% (w/v) NaCl (optimum 20%) and 0.1-1.0 M MgCl₂ (optimum 0.3-0.5 M) at pH 5.0-9.0 (optimum 7.0). Phylogenetic analysis based on the 16S rRNA sequence showed that this strain was related to two species within the genus Halobellus (Hbs.), with 98.4% and 95.8% similarity to Hbs. salinus CSW2.24.4 ^T and Hbs. clavatus TNN18^T, respectively. The major polar lipids of the strain MBLA160^T were phosphatidylglycerol, phosphatidylglycerol sulfate, and phosphatidylglycerol phosphate methyl ester. The genome size, G + C content, and N50 value of MBLA0160^T were 3.49 Mb, 66.5 mol%, and 620,127 bp, respectively. According to predicted functional proteins of strain MBLA0160^T, the highest category was amino acid transport and metabolism. Genome rapid annotation showed that amino acid and derivatives was the most subsystem feature counts. Pan-genomic analysis showed that strain MBLA0160^T had 97 annotated unique KEGG, which were mainly included metabolism and environmental information processing. Ortholog average nucleotide identities (OrthoANI) and in silico DNA-DNA hybridization (isDDH) values between the strain MBLA0160^T and other strains of the genus Halobellus were under 84,4% and 28.1%, respectively. The genome of strain MBLA0160^T also contain the biosynthetic gene cluster for C₅₀ carotenoid as secondary metabolite. Based on the phylogenetic, phenotypic, chemotaxonomic properties, and comparative genomic analyses, strain MBLA0160^T is considered to represent a novel species of the genus Halobellus, for which the name Halobellus ruber sp. nov. is proposed. The type strain is MBLA0160^T (= KCTC 4291 ^T = JCM 34172 ^T).

Halobellus captivus sp. nov., an extremely halophilic archaeon isolated from a subterranean salt mine

An extremely halophilic archaeon, strain ZY21^T, was isolated from a subterranean rock salt sample in Yunnan, China. Colonies of strain ZY21^T on nutrient-rich agar plates are orange, wet and transparent. Cells are pleomorphic, motile, Gram-stain negative and lyse in distilled water. Cells can grow at 20-55 °C (optimum 42 °C), in the presence of 15-30% (w/v) NaCl (optimum 18-20%) and at pH 6.0-9.5 (optimum 7.5). Mg²⁺ is required for growth (optimum 0.3 M). The major polar lipids of strain ZY21^T are phosphatidylglycerol, phosphatidylglycerol sulfate and phosphatidylglycerol phosphate methyl ester, sulfated mannosyl-glucosyl-glycerol diether-1 and seven unidentified glycolipids. Sequence similarity searches with the 16S rRNA gene and rpoB' gene showed that strain ZY21^T is closely related to Halobellus rufus CBA1103^T (sequence similarities: 97.5% for 16S rRNA gene and 93.3% for rpoB' gene). The DNA G+C content of strain ZY21^T was determined to be 63.0 mol% based on the draft genome sequence. Genome-based sequence similarity analysis showed that the values of the ANI, AAI, and DDH were far below the boundary for delineation of new species. Phenotypic, chemotaxonomic characteristics and phylogenetic properties suggest that strain ZY21^T represents a novel species in the genus Halobellus, for which the name Halobellus captivus sp. nov. is proposed. The type strain is ZY21^T (= CGMCC 1.16343^T = NBRC 113439^T).

Bacterial and Archaeal Diversity in Hypersaline Cyanobacterial Mats Along a Transect in the Intertidal Flats of the Sultanate of Oman

Hypersaline intertidal zones are highly dynamic ecosystems that are exposed to multiple extreme environmental conditions including rapidly and frequently changing parameters (water, nutrients, temperature) as well as highly elevated salinity levels often caused by high temperatures and evaporation rates. Microbial mats in most extreme settings, as found at the coastline of the subtropical-arid Arabian Peninsula, have been relatively less studied compared to their counterparts around the world. We report, here, for the first time on the diversity of the bacterial and archaeal communities of marine microbial mats along an intertidal transect in a wide salt flat with strongly increased salinity employing Illumina MiSeq technology for amplicon sequencing of 16S rRNA gene fragments. Microbial communities were dominated by typical halotolerant to halophilic microorganisms, with clear shifts in community composition, richness, and diversity along the transect. Highly adapted specialists (e.g., Euhalothece, Salinibacter, Nanohaloarchaeota) were mainly found at the most extreme, upper tidal sites and less specialized organisms with wide tolerance ranges (e.g., Lyngbya, Rhodovibrio, Salisaeta, Halobacteria) in intermediate sites of the transect. The dominating taxa in the lower tidal sites were typical members of well-stabilized mats (e.g., Coleofasciculus, Anaerolineaceae, Thaumarchaeota). Up to 40% of the archaeal sequences per sample represented so far unknown phyla. In conclusion, the bacterial richness and diversity increased from upper towards lower tidal sites in line with increasing mat stabilization and functional diversity, opposed to that of cyanobacteria only and archaea, which showed their highest richness and diversity in upper tidal samples.

Systematics of haloarchaea and biotechnological potential of their hydrolytic enzymes

Halophilic archaea, also referred to as haloarchaea, dominate hypersaline environments. To survive under such extreme conditions, haloarchaea and their enzymes have evolved to function optimally in environments with high salt concentrations and, sometimes, with extreme pH and temperatures. These features make haloarchaea attractive sources of a wide variety of biotechnological products, such as hydrolytic enzymes, with numerous potential applications in biotechnology. The unique trait of haloarchaeal enzymes, haloenzymes, to sustain activity under hypersaline conditions has extended the range of already-available biocatalysts and industrial processes in which high salt concentrations inhibit the activity of regular enzymes. In addition to their halostable properties, haloenzymes can also withstand other conditions such as extreme pH and temperature. In spite of these benefits, the industrial potential of these natural catalysts remains largely unexplored, with only a few characterized extracellular hydrolases. Because of the applied impact of haloarchaea and their specific ability to live in the presence of high salt concentrations, studies on their systematics have intensified in recent years, identifying many new genera and species. This review summarizes the current status of the haloarchaeal genera and species, and discusses the properties of haloenzymes and their potential industrial applications.

Occurrence of viable, red-pigmented haloarchaea in the plumage of captive flamingoes

Flamingoes (Phoenicopterus spp.) whose plumage displays elegant colors, inhabit warm regions close to the ocean throughout the world. The pink or reddish color of their plumage originates from carotenoids ingested from carotenoid-abundant food sources, since flamingoes are unable to synthesize these compounds de novo. In this study, viable red-colored archaeal strains classified as extremely halophilic archaea (i.e., haloarchaea) and belonging to the genera Halococcus and Halogeometricum were isolated from the plumage of flamingoes in captivity. Detailed analysis for haloarchaeal community structure in flamingo feathers based on metagenomic data identified several haloarchaeal genera and unclassified sequences of the class Halobacteria at the genus level. Carotenoid pigment analyses showed that a bacterioruberin precursor carotenoid in haloarchaea was identical to one of the pigments found in flamingo plumage. To the best of our knowledge, this is the first report of viable extremophilic archaea in avian plumage, thus contributing to our understanding of the ecology of haloarchaea. The potential influence of haloarchaea as an environmental factor determining avian plumage coloration should be investigated in further studies.

Halobellus ramosii sp. nov., an extremely halophilic archaeon isolated from a saline-wetland wildfowl reserve

An extremely halophilic archaeon, strain S2FP14T, was isolated from a brine sample from the inland hypersaline lake Fuente de Piedra, a saline-wetland wildfowl reserve located in the province of Málaga in southern Spain. Colonies were red-pigmented and the cells were Gram-staining-negative, motile and pleomorphic. S2FP14T was able to grow in media containing 12.5-30 % (w/v) total salts (optimum 20 %) at pH 7-8.5 (optimum 7.5) and at 25-50 °C (optimum 37 °C). The 16S rRNA gene sequence analysis indicated that this strain represented a member of the genus Halobellus. S2FP14T showed a similarity of 99.5 % to Halobellus inordinatus YC20T, 96.1 % to Halobellus litoreus GX31T, 95.9 % to Halobellus limi TBN53T, 95.5 % to Halobellus rarus YC21T, 95.2 % to Halobellus rufus CBA1103T, 94.6 % to Halobellus salinus CSW2.24.4T and 94.6 % to Halobellus clavatus TNN18T. The rpoB' gene sequence similarity of strain S2FP14T was 97.4 % to 87.6 % with members of genus Halobellus. The major phospholipids of strain S2FP14T were phosphatidylglycerol phosphate methyl ester and phosphatidylglycerosulfate, plus a very small amount of phosphatidylglycerol and an archaeal analogue of bisphosphatidylglycerol. With regard to glycolipid composition, the most abundant glycolipids were the sulfated diglycosyl diphytanilglyceroldiether and a glycosyl-cardiolipin. The G+C content of strain S2FP14T genomic DNA was 61.4 mol%. The DNA-DNA hybridization between strain S2FP14T and Halobellus inordinatus JCM 18361T was 51 %. Based on the phylogenetic, phenotypic and chemotaxonomic features, a novel species, Halobellus ramosii sp. nov. is proposed. The type strain is S2FP14T ( = CECT 8167T = DSM 26177T).

Draft genome sequence of the agarolytic haloarchaeon Halobellus rufus type strain CBA1103

The extremely halophilic archaeon Halobellus rufus type strain CBA1103(T) (CECT 8423(T) and JCM 19434(T)) was isolated from non-purified solar salt and characterized as an agarase producer. The draft genome sequence contains 3852 303 bp with a G + C content of 64.1% and includes genomic information on various carbohydrate-active enzymes. This is the first sequenced genome of the genus Halobellus, and is expected to provide general sequence information for halophilic carbohydrate-active enzymes and opportunities for biotechnological applications of novel halophilic enzymes.

Deciphering archaeal glycolipids of an extremely halophilic archaeon of the genus Halobellus by MALDI-TOF/MS

Polar membrane lipids of an archaeal microorganism recently isolated from the natural salt lake Fuente de Piedra (Málaga, Spain) have been studied by means of TLC in combination with MALDI-TOF mass spectrometry. The major phospholipids are the ether lipids phosphatidylglycerophosphate methyl ester and phosphatidylglycerosulfate, while phosphatidylglycerol is barely detectable; in addition the bisphosphatidylglycerol (archaeal cardiolipin) has been detected for the first time in a representative of the genus Halobellus. The structures of glycolipids, including a glycosyl-cardiolipin, have been elucidated by post source decay (PSD) mass spectrometry analysis. Besides the monosulfated diglycosyl diphytanylglyceroldiether, two variants of a bis-sulfated diglycosyl diphytanylglyceroldiether have been identified; furthermore the glycosyl-cardiolipin is found to have the same structure of the analogue present in Halorubrum trapanicum and Haloferax volcanii. The role of the abundant sulfated glycolipids in facing high extracellular salinity is discussed.

List of new names and new combinations previously effectively, but not validly, published

The purpose of this announcement is to effect the valid publication of the following effectively published new names and new combinations under the procedure described in the Bacteriological Code (1990 Revision). Authors and other individuals wishing to have new names and/or combinations included in future lists should send three copies of the pertinent reprint or photocopies thereof, or an electronic copy of the published paper to the IJSEM Editorial Office for confirmation that all of the other requirements for valid publication have been met. It is also a requirement of IJSEM and the ICSP that authors of new species, new subspecies and new combinations provide evidence that types are deposited in two recognized culture collections in two different countries. It should be noted that the date of valid publication of these new names and combinations is the date of publication of this list, not the date of the original publication of the names and combinations. The authors of the new names and combinations are as given below. Inclusion of a name on these lists validates the publication of the name and thereby makes it available in the nomenclature of prokaryotes. The inclusion of a name on this list is not to be construed as taxonomic acceptance of the taxon to which the name is applied. Indeed, some of these names may, in time, be shown to be synonyms, or the organisms may be transferred to another genus, thus necessitating the creation of a new combination.