ABSTRACT
Two Gram-stain-negative, aerobic, rod-shaped, non-endospore-forming and motile bacterial strains, designated IT1137T and S025T, were isolated from an intertidal sediment sample collected from the Fildes Peninsula (King George Island, Maritime Antarctica) and a soil sample under red snow in the Ny-Ålesund region (Svalbard, High Arctic), respectively. The 16S rRNA gene sequence similarity values grouped them in the genus Pseudomonas. The two strains were characterized phenotypically using API 20E, API 20NE, API ZYM and Biolog GENIII tests and chemotaxonomically by their fatty acid contents, polar lipids and respiratory quinones. Multilocus sequence analysis (concatenated 16S rRNA, gyrB, rpoB and rpoD sequences), together with genome comparisons by average nucleotide identity and digital DNA-DNA hybridization, were performed. The results showed that the similarity values of the two isolates with the type strains of related Pseudomonas species were below the recognized thresholds for species definition. Based on polyphasic taxonomy analysis, it can be concluded that strains IT1137T and S025T represent two novel species of the genus Pseudomonas, for which the names Pseudomonas paeninsulae sp. nov. (type strain IT1137T=PMCC 100533T=CCTCC AB 2023226T=JCM 36637T) and Pseudomonas svalbardensis sp. nov. (type strain S025T=PMCC 200367T= CCTCC AB 2023225T=JCM 36638T) are proposed.
Subject(s)
Bacterial Typing Techniques , DNA, Bacterial , Fatty Acids , Geologic Sediments , Multilocus Sequence Typing , Nucleic Acid Hybridization , Phylogeny , Pseudomonas , RNA, Ribosomal, 16S , Sequence Analysis, DNA , Soil Microbiology , RNA, Ribosomal, 16S/genetics , Pseudomonas/genetics , Pseudomonas/classification , Pseudomonas/isolation & purification , Geologic Sediments/microbiology , DNA, Bacterial/genetics , Arctic Regions , Antarctic Regions , Fatty Acids/analysis , Svalbard , Base Composition , Quinones/analysisABSTRACT
Pseudomonas species are known for their diverse metabolic abilities and broad ecological distribution. They are fundamental components of bacterial communities and perform essential ecological functions in the environment. A psychrotrophic Pseudomonas sp. IT1137 was isolated from intertidal sediment in the coastal region of the Fildes Peninsula, King George Island, Antarctica. The strain contained a circular chromosome of 5,346,697 bp with a G + C content of 61.66 mol% and one plasmid of 4481 bp with a G + C content of 64.61 mol%. A total of 4848 protein-coding genes, 65 tRNA genes and 15 rRNA genes were obtained. Genome sequence analysis revealed that strain IT1137 not only is a potentially novel species of the genus Pseudomonas but also harbors functional genes related to nitrogen, sulfur and phosphorus cycling. In addition, genes involved in alkane degradation, ectoine synthesis and cyclic lipopeptide (CLP) production were detected in the bacterial genome. The results indicate the potential of the strain Pseudomonas sp. IT1137 for biotechnological applications such as bioremediation and secondary metabolite production and are helpful for understanding bacterial adaptability and ecological function in cold coastal environments.
Subject(s)
Alkanes , Cold Temperature , Genome, Bacterial , Geologic Sediments , Pseudomonas , Pseudomonas/genetics , Antarctic Regions , Geologic Sediments/microbiology , Alkanes/metabolism , Whole Genome Sequencing , Biodegradation, EnvironmentalABSTRACT
Bacteria of the genus Oceanisphaera in the class Gammaproteobacteria are widely distributed in marine environments. Oceanisphaera sp. IT1-181 was isolated from intertidal sediment in the coastal region of the Chinese Great Wall Station on the Fildes Peninsula, King George Island, Antarctica. Here, we sequenced the complete genome of strain IT1-181, which contained a single chromosome of 3,572,184 bp (G + C content of 49.89 mol%) with five plasmids. A total of 3229 protein-coding genes, 88 tRNA genes, and 25 rRNA genes were obtained. Genome sequence analysis revealed that strain IT1-181 was not only a potentially novel species of the genus Oceanisphaera, but also harbored genes involved in biosynthesizing ectoine as well as poly-ß-hydroxybutyric acid (PHB). In addition, genes of a complete type I-E CRISPR-Cas system were found in the bacterium. The results indicate the potential of strain Oceanisphaera sp. IT1-181 in biotechnology and are helpful for us understanding its ecological roles in the changing Antarctic intertidal zone environment.
Subject(s)
Aeromonadaceae , Seawater , Seawater/microbiology , Fatty Acids/analysis , Antarctic Regions , DNA, Bacterial/genetics , Phylogeny , RNA, Ribosomal, 16S , Bacterial Typing Techniques , Plasmids/genetics , Bacteria/genetics , Aeromonadaceae/genetics , Sequence Analysis, DNAABSTRACT
BACKGROUND: Biological denitrification has been commonly adopted for the removal of nitrogen from sewage effluents. However, due to the low temperature during winter, microorganisms in the wastewater biological treatment unit usually encounter problems such as slow cell growth and low enzymatic efficiency. Hence, the isolation and screening of cold-tolerant aerobic denitrifying bacteria (ADB) have recently drawn attention. In our previous study, two Pseudomonas strains PMCC200344 and PMCC200367 isolated from Arctic soil demonstrated strong denitrification ability at low temperatures. The two Arctic strains show potential for biological nitrogen removal from sewage in cold environments. However, the genome sequences of these two organisms have not been reported thus far. RESULTS: Here, the basic characteristics and genetic diversity of strains PMCC200344 and PMCC200367 were described, together with the complete genomes and comparative genomic results. The genome of Pseudomonas sp. PMCC200344 was composed of a circular chromosome of 6,478,166 bp with a G + C content of 58.60% and contained a total of 5,853 genes. The genome of Pseudomonas sp. PMCC200367 was composed of a circular chromosome of 6,360,061 bp with a G + C content of 58.68% and contained 5,801 genes. Not only prophages but also genomic islands were identified in the two Pseudomonas strains. No plasmids were observed. All genes of a complete set of denitrification pathways as well as various putative cold adaptation and heavy metal resistance genes in the genomes were identified and analyzed. These genes were usually detected on genomic islands in bacterial genomes. CONCLUSIONS: These analytical results provide insights into the genomic basis of microbial denitrification in cold environments, indicating the potential of Arctic Pseudomonas strains in nitrogen removal from sewage effluents at low temperatures.
Subject(s)
Denitrification , Sewage , Comparative Genomic Hybridization , Genomics , Nitrogen , Pseudomonas/geneticsABSTRACT
Members of the genus Pseudomonas have been frequently isolated from the marine environment, indicating their ecological role in native habitats. One bacterial strain, Pseudomonas sp. BSw22131, was isolated from seawater in Kongsfjorden, Svalbard. The bacterium can grow with algae-derived dimethylsulfoniopropionate (DMSP) as the sole carbon source. Here, we sequenced the complete genome of strain BSw22131, which contained a single circular chromosome of 5,739,290 (G + C content of 58.23 mol%) without any plasmids. A total of 5362 protein-coding genes, 65 tRNA genes, and 16 rRNA genes were obtained. Genome sequence analysis revealed that strain BSw22131 was not only a potential novel species of the genus Pseudomonas but also different from Pseudomonas sp. DMSP-1 that was isolated from the same habitat and also utilized DMSP as the sole carbon source for growth. The results can be helpful for understanding the catabolism of the genus Pseudomonas in sulfur cycling in the Arctic fjord ecosystem.
Subject(s)
Ecosystem , Sulfonium Compounds , Bacteria/genetics , Seawater/microbiology , Sulfonium Compounds/metabolism , PhylogenyABSTRACT
Members of the genus Devosia are known for their abilities to degrade deoxynivalenol (DON). The type strain Devosia beringensis S02T (= JCM 33772 = CCTCC AB 2019343) was isolated from sediment of the Bering Sea and identified in 2021. However, the genome sequence of D. beringensis S02T remains unclear, which complicates the exploration into the function and ecological role of this strain in marine sediment. The genome of D. beringensis S02T contained a 4,048,765 bp chromosome with a G + C content of 63.84 mol%. Potential genes involved in DON degradation were found in the genome. In addition, multiple genes involved in polysaccharide degradation, including agarose, chitin, carrageen, pectate, starch, and xylan, were also annotated in the genome. These findings indicated the potential of strain S02T to be used for DON degradation and its ecological function in the carbon cycle in marine sediment.
Subject(s)
Hyphomicrobiaceae , DNA, Bacterial/genetics , Hyphomicrobiaceae/genetics , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , TrichothecenesABSTRACT
Strain S02T was isolated from a surface sediment sample collected from the Bering Sea (64.3361° N, 170.9541° W). The cells were Gram-stain-negative, motile and rod-shaped. The temperature range for growth was 4-25 °C and the pH for growth was 5.5-9.0, with optimum growth occurring at 20-25 °C and pH 7.0-8.0. Growth occurred in the presence of 0-7â% (w/v) NaCl (optimum, 2-5â%). Strain S02T had menaquinone-8 as the major respiratory quinone and summed feature 8 (C18â:â1 ω7c and/or C18â:â1 ω6c), C16:0, C17â:â0 cyclo, summed feature 3 (C16â:â1 ω7c /C16â:â1 ω7c), C17â:â0 and C18â:â0 as major fatty acids. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and two glycolipids. The genomic DNA G+C content was approximately 63.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S02T belonged to the genus Devosia. Strain S02T showed the highest sequence similarities to Devosia psychrophila Cr7-05T (97.5â%), Devosia naphthalenivorans CM5-1T (97.7â%), Devosia submarina KMM 9415T (97.4â%), Devosia epidermidihirudinis E84T (97.44â%), Devosia euplotis LIV5T (97.1â%) and Devosia limi DSM 17137T (96.7â%). On the basis of phylogenetic analyses and phenotypic characteristics, a novel species of the genus Devosia, Devosia beringensis sp. nov., is proposed, with the type strain S02T (=JCM 33772=CCTCC AB 2019343).
Subject(s)
Hyphomicrobiaceae/classification , Phylogeny , Seawater/microbiology , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/chemistry , Hyphomicrobiaceae/isolation & purification , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistryABSTRACT
The genus Sulfitobacter has been mostly found in marine and hypersaline environments. Members of this genus were observed to be associated with marine microalgae by inducing cell death of algae and degrading of algae-derived dimethylsulfoniopropionate (DMSP). Here we reported the complete genome sequence of strain Sulfitobacter sp. BSw21498 isolated from seawater of Kongsfjorden, an Arctic fjord in Svalbard. The strain contained a circular chromosome of 3,097,372 bp with G+C content of 58.55 mol% and a plasmid of 147,547 bp with G+C content of 56.53 mol%. In particular, a gene for DMSP lyase DddL was found in the genome, rendering Sulfitobacter sp. strain BSw21498 one of the Rhodobacterales bacteria equipped with the potential for DMSP degradation.
Subject(s)
Genome, Bacterial , Rhodobacteraceae/genetics , Seawater/microbiology , Svalbard , Whole Genome SequencingABSTRACT
Dimethylsulfoniopropionate (DMSP) is an organic sulfur compound that occurs in large amounts in oceans around the world, and it plays an important role in the global sulfur cycle. DMSP released into seawater can be rapidly catabolized by bacteria via two pathways, namely, demethylation or cleavage pathway. Members of the Roseobacter clade frequently possess enzymes involved in the DMSP demethylation or cleavage pathway. We tried to measure the diversity of genes encoding DMSP demethylase (dmdA) and DMSP lyases (dddD, dddL, and dddP) in bacteria in the surface seawater of Ardley Cove and Great Wall Cove in Antarctic Maxwell Bay using DMSP degradation gene clone library analysis. Although we did not detect sequences related to the dddD or dddL gene, both bacterial dmdA and dddP genes found in the two coves were completely confined to the Roseobacter clade, which indicated that this clade plays a significant role in DMSP catabolism in the coastal seawaters of Maxwell Bay. In addition, compared with bacterial DMSP degradation genes in Arctic coastal seawater, our results suggest that both bipolar and endemic bacterial DMSP degradation genes exist in polar marine environments. The findings of this study improve our knowledge of the distribution of DMSP degradation genes in polar marine ecosystems.
Subject(s)
Bays/microbiology , Roseobacter/metabolism , Seawater/microbiology , Sulfonium Compounds/metabolism , Sulfur/metabolism , Antarctic Regions , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Biodiversity , Carbon-Sulfur Lyases/genetics , Carbon-Sulfur Lyases/metabolism , Phylogeny , Roseobacter/classification , Roseobacter/genetics , Roseobacter/isolation & purificationABSTRACT
Fjords and continental shelves represent distinct marine ecosystems in the pan-arctic region. Kongsfjorden is a glacial fjord that is located on the west coast of Svalbard, and is influenced by both Atlantic and Arctic water masses. The Bering Sea consists of a huge continental shelf in the northeast and a deep ocean basin in the southwest, and is influenced by Pacific water. Microbial community compositions of Arctic sediment samples BJ4 from outer basin and BJ36 from inner basin of Kongsfjorden and sub-Arctic samples NEC5 from shallow shelf and DBS1 from deep basin region of the northern Bering Sea were investigated using 454 pyrosequencing of archaeal and bacterial 16S rRNA genes. Most archaeal sequences in the sediments were related to Thaumarchaeota, though Euryarchaeota were more abundant in the Arctic glacier-influencing inner basin sediment BJ36. Thaumarchaeota Group C3 was the dominant archaeal population in all samples. Proteobacteria and Bacteroidetes dominated the sediment bacterial communities. Acidobacteria and Actinobacteria were also dominant in the northern Bering Sea samples. Alphaproteobacteria and Epsilonproteobacteria were the two main classes in Kongsfjorden sediment bacterial communities while Deltaproteobacteria and Gammaproteobacteria were dominant in the northern Bering Sea sediments. Differences in the presence and abundance of other dominant archaeal and bacterial populations were observed among sediment samples. In contrast to archaeal community differences that the Arctic BJ36 archaeal community was distinct from the sub-Arctic sediments and the Arctic outer basin sediment BJ4, cluster analysis based on bacterial OTU (operational taxonomic unit) distributions indicated that the Arctic and sub-Arctic bacterial communities segregated from one another. These results suggest that the sediment archaeal and bacterial community compositions can be driven by different environmental factors. Differences in the presence and abundance of particular archaeal species (e.g., Candidatus Nitrosopumilus and Methanococcoides) or bacterial species (e.g., Sulfurimonas, Sulfurovum, and Desulfobulbaceae) involved in biogeochemical cycles were also observed among sediment samples. At the same time, despite the community variation, some phylotypes (e.g., Marinicella) were dominant in all sediments. This study indicates diverse microbial communities inhabiting pan-arctic marine sediments, and highlights potential roles for Archaea and Bacteria in global biogeochemical cycles in these environments.
ABSTRACT
Dimethylsulfoniopropionate (DMSP), which is the major source of organic sulfur in the world's oceans, plays a significant role in the global sulfur cycle. This compound is rapidly degraded by marine bacteria either by cleavage to dimethylsulfide (DMS) or demethylation to 3-methylmercaptopropionate (MMPA). The diversity of genes encoding bacterial demethylation (dmdA) and DMS production (dddL and dddP) were measured in Arctic Kongsfjorden. Both dmdA and dddL genes were detected in all stations along a transect from the outer to the inner fjord, while dddP gene was only found in the outer and middle parts of the fjord. The dmdA gene was completely confined to the Roseobacter clade, while the dddL gene was confined to the genus Sulfitobacter. Although the dddP gene pool was also dominated by homologs from the Roseobacter clade, there were a few dddP genes showing close relationships to both Alphaproteobacter and Gammaproteobacter. The results of this study suggest that the Roseobacter clade may play an important role in DMSP catabolism via both demethylation and cleavage pathways in surface waters of Kongsfjorden during summer.
Subject(s)
Genes, Bacterial , Seawater/microbiology , Sulfonium Compounds/metabolism , Arctic Regions , Bacteria/genetics , Bacteria/isolation & purification , Bacteria/metabolism , Biodegradation, Environmental , DNA, Bacterial/genetics , Genetic Variation , Phylogeny , Propionates/metabolism , Rhodobacteraceae/genetics , Rhodobacteraceae/metabolism , Roseobacter/genetics , Roseobacter/metabolism , Sulfhydryl Compounds/metabolism , Sulfides/metabolism , Sulfur/metabolism , Water Pollutants, Chemical/metabolismABSTRACT
A Gram-stain-negative, non-motile, non-spore-forming, non-pigmented, oxidase- and catalase-positive bacterial strain, designated BIc20019T, was isolated from the ice core of Austre Lovénbreen in Ny-Ålesund, Svalbard. The temperature and NaCl ranges for growth were 4-34 °C (optimum, 25-29 °C) and 0-8% (w/v) (optimum, 2-4%). Analysis of the 16S rRNA gene sequence indicated that strain BIc20019T belonged to the genus Psychrobacter and was closely related to Psychrobacter arcticus 273-4T, Psychrobacter cryohalolentis K5T, 'Psychrobacter fjordensis' BSw21516B, Psychrobacter fozii LMG 21280T, Psychrobacter luti LMG 21276T and Pyschrobacter okhotskensis MD17T at greater than 99% similarity. Phylogenetic analysis based on gyrB gene sequences revealed highest similarity (93.6%) to P. okhotskensis MD17T. However, DNA hybridization experiments revealed a low level of DNA-DNA relatedness (<59%) between strain BIc20019T and its closest relatives. Strain BIc20019T contained ubiquinone-8 (Q-8) as the predominant respiratory quinone, and C18:1ω9c and summed feature 3 (C16:1ω7c and/or iso-C15:0 2-OH) as the major fatty acids. It had a DNA G+C content of 46.3âmol%. The polar lipid profile of strain BIc20019T was mainly composed of phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. Owing to the differences in phenotypic and chemotaxonomic characteristics, phylogenetic analysis based on 16S rRNA gene and gyrB gene sequences, and DNA-DNA relatedness data, the isolate merits classification within a novel species for which the name Psychrobacter glaciei sp. nov. is proposed. The type strain is BIc20019T (=KCTC 42280T = CCTCC AB 2014019T).
Subject(s)
Ice Cover/microbiology , Phylogeny , Psychrobacter/classification , Arctic Regions , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/chemistry , Genes, Bacterial , Molecular Sequence Data , Nucleic Acid Hybridization , Phospholipids/chemistry , Psychrobacter/genetics , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Svalbard , Ubiquinone/chemistryABSTRACT
A Gram-negative, non-motile, non-spore-forming, psychrotolerant and halotolerant bacterium designated BSw21516B(T), was obtained from seawater in Kongsfjorden, a glacial fjord in the Arctic Svalbard and subjected to taxonomic analysis using a polyphasic approach. This bacterium was observed to optimally grow at 25-29 °C; between at 4 and 34 °C, but not at >35 °C; and in the presence of 0-8 % (w/v) NaCl at an optimum concentration of 2-5 % (w/v) NaCl. Strain BSw21516B(T) was found to contain Ubiquinone-8 (Q-8) as a predominant respiratory lipoquinone and C18:1 ω9c and summed feature 3 (C16:1 ω7c and/or iso-C15:0 2-OH) as predominant cellular fatty acids. Phylogenetic analysis of 16S rRNA and gyrB gene sequences showed that this isolate belongs to the genus Psychrobacter and is closely related to Psychrobacter fozii LMG 21280(T), which was isolated from a sediment sample in Antarctica. DNA hybridization experiments revealed a low level of DNA-DNA relatedness (less than 58.6 %) between strain BSw21516B(T) and its closest relatives. Based on these results a new species Psychrobacter fjordensis sp. nov. is proposed (type strain BSw21516B(T) = KCTC 42279(T) = CCTCC AB 2014020(T)).
Subject(s)
Psychrobacter/classification , Psychrobacter/isolation & purification , Seawater/microbiology , Arctic Regions , Bacterial Typing Techniques , Cluster Analysis , Cytosol/chemistry , DNA Gyrase/genetics , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Estuaries , Fatty Acids/analysis , Molecular Sequence Data , Nucleic Acid Hybridization , Phylogeny , Psychrobacter/genetics , Psychrobacter/physiology , Quinones/analysis , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Sodium Chloride/metabolism , Svalbard , TemperatureABSTRACT
The bacterioplankton not only serves critical functions in marine nutrient cycles, but can also serve as indicators of the marine environment. The compositions of bacterial communities in the surface seawater of Ardley Cove and Great Wall Cove were analyzed using a 16S rRNA multiplex 454 pyrosequencing approach. Similar patterns of bacterial composition were found between the two coves, in which Bacteroidetes, Alphaproteobacteria, and Gammaproteobacteria were the dominant members of the bacterioplankton communities. In addition, a large fraction of the bacterial sequence reads (on average 5.3 % per station) could not be assigned below the domain level. Compared with Ardley Cove, Great Wall Cove showed higher chlorophyll and particulate organic carbon concentrations and exhibited relatively lower bacterial richness and diversity. Inferred metabolisms of summer bacterioplankton in the two coves were characterized by chemoheterotrophy and photoheterotrophy. Results suggest that some cosmopolitan species (e.g., Polaribacter and Sulfitobacter) belonging to a few bacterial groups that usually dominate in marine bacterioplankton communities may have similar ecological functions in similar marine environments but at different geographic locations.
Subject(s)
Bacteria/classification , Bacteria/genetics , Biodiversity , Plankton/classification , Plankton/genetics , Seawater/microbiology , Alphaproteobacteria/classification , Alphaproteobacteria/genetics , Alphaproteobacteria/metabolism , Antarctic Regions , Bacteria/metabolism , Bacteroidetes/classification , Bacteroidetes/genetics , Bacteroidetes/metabolism , Gammaproteobacteria/classification , Gammaproteobacteria/genetics , Gammaproteobacteria/metabolism , Genes, rRNA , Oxygen/analysis , Plankton/metabolism , RNA, Ribosomal, 16S/genetics , Seawater/chemistryABSTRACT
Two 16S rRNA gene clone libraries Cores 1U and 2U were constructed using two ice core samples collected from Austre Lovénbreen glacier in Svalbard. The two libraries yielded a total of 262 clones belonging to 59 phylotypes. Sequences fell into 10 major lineages of the domain Bacteria, including Proteobacteria (alpha, beta, gamma and delta subdivisions), Bacteroidetes, Actinobacteria, Firmicutes, Acidobacteria, Deinococcus-Thermus, Chloroflexi, Planctomycetes, Cyanobacteria and candidate division TM7. Among them, Bacteroidetes, Actinobacteria, Alphaproteobacteria and Cyanobacteria were most abundant. UniFrac data showed no significant differences in community composition between the two ice cores. A total of nineteen bacterial strains from the genera Pseudoalteromonas and Psychrobacter were isolated from the ice cores. Phylogenetic and phenotypic analyses revealed a close relationship between the ice core isolates and bacteria in marine environments, indicating a wide distribution of some bacterial phylotypes in both terrestrial and marine ecosystems.
Subject(s)
Bacteria/classification , Bacteria/isolation & purification , Ice Cover/microbiology , Bacteria/genetics , Ecosystem , Ice , Molecular Sequence Data , Phylogeny , RNA, Ribosomal, 16S/genetics , SvalbardABSTRACT
Fjords and open oceans are two typical marine ecosystems in the Arctic region, where glacial meltwater and sea ice meltwater have great effects on the bacterioplankton community structure during the summer season. This study aimed to determine the differences in bacterioplankton communities between these two ecosystems in the Arctic region. We conducted a detailed census of microbial communities in Kongsfjorden (Spitsbergen) and the Chukchi Borderland using high-throughput pyrosequencing of the 16S rRNA gene. Gammaproteobacteria and Bacteroidetes were the dominant members of the bacterioplankton community in Kongsfjorden. By contrast, the most abundant bacterial groups in the surface seawater samples from the Chukchi Borderland were Alphaproteobacteria and Actinobacteria. Differences in bacterial communities were found between the surface and subsurface waters in the investigation area of the Chukchi Borderland, and significant differences in bacterial community structure were also observed in the subsurface water between the shelf and deep basin areas. These results suggest the effect of hydrogeographic conditions on bacterial communities. Ubiquitous phylotypes found in all the investigated samples belonged to a few bacterial groups that dominate marine bacterioplankton communities. The sequence data suggested that changes in environmental conditions result in abundant rare phylotypes and reduced amounts of other phylotypes.
Subject(s)
Actinobacteria , Alphaproteobacteria , Bacteroidetes , Gammaproteobacteria , Microbial Consortia , Plankton/microbiology , Actinobacteria/classification , Actinobacteria/genetics , Actinobacteria/isolation & purification , Alphaproteobacteria/classification , Alphaproteobacteria/genetics , Alphaproteobacteria/isolation & purification , Arctic Regions , Bacteroidetes/classification , Bacteroidetes/genetics , Bacteroidetes/isolation & purification , Base Sequence , Gammaproteobacteria/classification , Gammaproteobacteria/genetics , Gammaproteobacteria/isolation & purification , Genes, rRNA , Microbial Consortia/genetics , Molecular Sequence Data , Phylogeny , RNA, Ribosomal, 16S/genetics , Seawater/microbiology , Sequence Analysis, DNA , SvalbardABSTRACT
A yellow-coloured, rod-shaped, Gram-reaction- and Gram-staining-negative, non-motile and aerobic bacterium, designated strain ZS1-8(T), was isolated from a sample of sandy intertidal sediment collected from the Antarctic coast. Flexirubin-type pigments were absent. In phylogenetic analyses based on 16S rRNA gene sequences, strain ZS1-8(T) formed a distinct phyletic line and the results indicated that the novel strain should be placed in a new genus within the family Flavobacteriaceae. In pairwise comparisons between strain ZS1-8(T) and recognized species, the levels of 16S rRNA gene sequence similarity were all <93.3 %. The strain required Ca(2+) and K(+) ions as well as NaCl for growth. Optimal growth was observed at pH 7.5-8.0, 17-19 °C and with 2-3 % (w/v) NaCl. The major fatty acids were iso-C(15 : 1) G, iso-C(15 : 0), summed feature 3 (iso-C(15 : 0) 2-OH and/or C(16 : 1)ω7c), an unknown acid with an equivalent chain-length of 13.565 and iso-C(17 : 0) 3-OH. The major respiratory quinone was MK-6. The predominant polar lipid was phosphatidylethanolamine. The genomic DNA G+C content was 43.9 mol%. Based on the phylogenetic, phenotypic and chemotaxonomic data, strain ZS1-8(T) represents a novel species in a new genus in the family Flavobacteriaceae for which the name Pricia antarctica gen. nov., sp. nov. is proposed. The type strain of the type species is ZS1-8(T) (= JCM 17291(T) = DSM 23421(T)).
Subject(s)
Flavobacteriaceae/classification , Phylogeny , Seawater/microbiology , Antarctic Regions , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/analysis , Flavobacteriaceae/genetics , Flavobacteriaceae/isolation & purification , Geologic Sediments/microbiology , Molecular Sequence Data , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivativesABSTRACT
The diversity and cold-active hydrolytic enzymes of culturable bacteria associated with sandy sediment from Nella Fjord, Eastern Antarctica (69°22'6â³ S, 76°21'45â³ E) was investigated. A total of 33 aerobic heterotrophic bacterial strains were isolated at 4 °C. These bacterial isolates could be sorted into 18 phylotypes based on the 16S rRNA gene sequence belonging to four phyla, namely Alphaproteobacteria, Gammaproteobacteria, Bacteroidetes and Actinobacteria. Only seven isolates were psychrophilic, 15 isolates were moderately psychrophilic, and 11 isolates were psychrotolerant. More than 72% of the isolates required sodium chloride to grow. Esterase, ß-glucosidase and proteases activities at 4 °C were detected in more than 45% of the strains while approximately 21%, 15% and 12% of the strains possessed lipase, amylase and chitinase, respectively. These results indicate that a relatively high culturable bacterial diversity is present within marine sediment of Nella Fjord and it could serve as an ideal candidate region for bioprospecting.
Subject(s)
Bacteria/enzymology , Bacterial Proteins/metabolism , Biodiversity , Geologic Sediments/microbiology , Hydrolases/metabolism , Bacteria/genetics , Bacteria/isolation & purification , Bacterial Proteins/genetics , Cold Temperature , Enzyme Activation , Hydrolases/genetics , Hydrolysis , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNAABSTRACT
A novel psychrotolerant bacterial strain, BCw111(T), was isolated from seawater samples from the Chukchi Sea in the Arctic Ocean. Cells of strain BCw111(T) were Gram-negative, motile, facultatively anaerobic, curved rods and were able to grow at 0-30 °C (optimum 23-25 °C). Strain BCw111(T) had Q-8 as the major respiratory quinone and contained iso-C(15â:â0) 2-OH and/or C(16â:â1)ω7c (28.13â%), C(16â:â0) (13.28â%) and C(17â:â1) (12.90â%) as the major cellular fatty acids. The genomic DNA G+C content was 41.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BCw11(T) formed a distinct lineage within the genus Colwellia and exhibited the highest 16S rRNA gene sequence similarity with Colwellia polaris 537(T) (97.8â%) and Colwellia aestuarii SMK-10(T) (97.1â%). Based on phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness, a novel species, Colwellia chukchiensis sp. nov., is proposed. The type strain is BCw111(T) (â=âCGMCC 1.9127(T) â=âLMG 25329(T) â=âDSM 22576(T)).
Subject(s)
Alteromonadaceae/classification , Alteromonadaceae/isolation & purification , Seawater/microbiology , Alteromonadaceae/genetics , Alteromonadaceae/physiology , Anaerobiosis , Arctic Regions , Bacterial Typing Techniques , Base Composition , Cluster Analysis , Cold Temperature , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Fatty Acids/analysis , Locomotion , Molecular Sequence Data , Nucleic Acid Hybridization , Oceans and Seas , Phylogeny , Quinones/analysis , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNAABSTRACT
Psychrotolerant Bacillus-like strains BR035(T) and BR011 were isolated from seawater of the Bering Sea and were characterized by means of a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that these strains were related to the members of the genus Bacillus and had the highest 16S rRNA gene sequence similarity with Bacillus korlensis ZLC-26(T). DNA-DNA hybridization experiments confirmed that strains BR035(T) and BR011 belonged to the same species and were distinct from their closest relatives. The cells were Gram-positive, rods, motile, spore-forming and psychrotolerant. The temperature range for growth was 4-42°C. The main respiratory quinone was MK-7. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unknown aminolipid and two unknown phospholipids. The major cellular fatty acids were iso-C15:0, anteiso-C15:0, iso-C14:0 and C16:1ω7c alcohol. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The genomic DNA G + C content was 37.6-37.8 mol%. On the basis of the phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness data, a novel species Bacillus beringensis is proposed and the type strain is BR035(T) (=CGMCC 1.9126(T)=DSM 22571(T)).