Pseudidiomarina sediminum sp. nov., a marine bacterium isolated from coastal sediments of Luoyuan Bay in China

The Hypersaline Soils of the Odiel Saltmarshes Natural Area as a Source for Uncovering a New Taxon: Pseudidiomarina terrestris sp. nov

The hypersaline soils of the Odiel Saltmarshes Natural Area are an extreme environment with high levels of some heavy metals; however, it is a relevant source of prokaryotic diversity that we aim to explore. In this study, six strains related to the halophilic genus Pseudidiomarina were isolated from this habitat. The phylogenetic study based on the 16S rRNA gene sequence and the fingerprinting analysis suggested that they constituted a single new species within the genus Pseudidiomarina. Comparative genomic analysis based on the OGRIs indices and the phylogeny inferred from the core genome were performed considering all the members of the family Idiomarinaceae. Additionally, a completed phenotypic characterization, as well as the fatty acid profile, were also carried out. Due to the characteristics of the habitat, genomic functions related to salinity and high heavy metal concentrations were studied, along with the global metabolism of the six isolates. Last, the ecological distribution of the isolates was studied in different hypersaline environments by genome recruitment. To sum up, the six strains constitute a new species within the genus Pseudidiomarina, for which the name Pseudidiomarina terrestris sp. nov. is proposed. The low abundance in all the studied hypersaline habitats indicates that it belongs to the rare biosphere in these habitats. In silico genome functional analysis suggests the presence of heavy metal transporters and pathways for nitrate reduction and nitrogen assimilation in low availability, among other metabolic traits.

Draft Genome Sequence of Idiomarina sp. Strain W-5T, Isolated from the Andaman Sea

Here, we report the draft genome sequence of Idiomarina sp. strain W-5T, which was isolated from the Andaman Sea. The genome encodes 2,207 proteins. The Idiomarina sp. strain W-5T whole-genome sequence will help us to understand the metabolic diversity in marine bacteria.

Here, we report the draft genome sequence of Idiomarina sp. strain W-5T, which was isolated from the Andaman Sea. The genome encodes 2,207 proteins. The Idiomarina sp. strain W-5T whole-genome sequence will help us to understand the metabolic diversity in marine bacteria.

Potential of mercury-tolerant bacteria for bio-uptake of mercury leached from discarded fluorescent lamps

In this study, ten bacterial strains were found to be mercury resistant after their isolation from Qatari coastal sediments. Tolerance was found to be up to 100-150 ppm for five strains. Those strains had optimum growth conditions at salinity level of 10 ppm NaCl and pH 7-8. Starting from a concentration 7.9 ppm of mercury extracted from fluorescent lamps and after 6 days of incubation at 37 °C, two isolated strains HA6 (Bacillus spp.) and HA9 (Acinetobacter sp.) showed 96.7% and 98.9% of mercury bio-uptake efficiency, respectively. Other strains were capable of removing more than 60% of extracted mercury.

Idiomarina mangrovi sp. nov., isolated from rhizosphere soil of a mangrove Avicennia marina forest

A Gram-staining negative, aerobic, motile and rod-shaped bacterium, designated ZQ330^T, was isolated from rhizosphere soil of a mangrove (Avicennia marina) forest of Zhangzhou, Fujian Province, China. The growth range of NaCl concentration was 0.5-10.0 % (w/v), with an optimum at 2.5-3.0 % (w/v), the temperature range for growth was 10-40 °C, with an optimum at 28-30 °C, the pH range for growth was pH 6.0-9.5, with an optimum at pH 7.5. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain ZQ330^T exhibited less than 97.0 % sequence similarity to all type strains with validly published names and revealed that strain ZQ330^T formed a distinct lineage in the genus Idiomarina. The average nucleotide identity, and in silico DNA-DNA hybridization values between strain ZQ330^T and the reference strains were 64.8-69.9 % and 27.5-28.4 %, respectively. Chemotaxonomic analysis indicated that the main respiratory quinone was Q-8, the predominant cellular fatty acids were iso-C15 : 0, iso-C17 : 0, summed feature 9 (C16 : 0 10-methyl and/or iso-C17 : 1ω9c), iso-C15 : 1F, C16 : 0, C18 : 0, summed feature 3 (C16 : 1ω8c and/or iso-C16 : 1 2-OH) and summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c). The polar lipid profile was composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified glycolipid, an unidentified aminolipid, an unidentified phospholipid and two unidentified lipids. Based on the genotypic, phenotypic, chemotaxonomic and phylogenetic features, strain ZQ330^T is considered to represent a novel species, for which the name Idiomarina mangrovi sp. nov. is proposed. The type strain is ZQ330^T (=MCCC 1K03495^T=KCTC 62455^T).

Genome-Based Analysis Reveals the Taxonomy and Diversity of the Family Idiomarinaceae

Idiomarinaceae is a family of Gram-stain negative, mesophilic euryhalophiles. To provide a robust framework for the evolutionary and taxonomic relationships of bacteria of this family, we compared herein the genomes of 36 type strains and 43 non-type strains using 16S rRNA gene sequences, core genome based 78 single-copy orthologous proteins, digital DNA-DNA hybridization and average nucleotide identity (ANI) estimation. The 79 bacteria of this family were consistently divided into taxon I, taxon II, and taxon III corresponding to the three genera Idiomarina, Pseudidiomarina, and Aliidiomarina, which contained 13 putative new genospecies in addition to 35 well-defined species represented by each type strain. Furthermore, genetic diversity of this family was evident at the genus- and species levels, and exceeded that which is defined currently by the named species. In view of multiple genotypic characteristics clearly distinct from the other two genera, we propose reinstating the genus Pseudidiomarina as a monophyletic taxon. Taken together, this is the first genome-based study of the taxonomy and diversity of bacteria within the family Idiomarinaceae, and will contribute to further insights into microbial evolution and adaptation to saline environments.

Idiomarina andamanensis sp. nov., an alkalitolerant bacterium isolated from Andaman Sea water

Two closely related aerobic, Gram-negative rod shaped bacteria (strain W5^T and W3) were isolated from Andaman Sea. Heterotrophic growth on marine agar was observed at 15-45 °C and pH 6-10. Strain W5^T showed maximum 16S rRNA sequence similarity of 99.58% with Idiomarina marina JCM 15083^T. DNA fingerprinting analysis by ERIC-REP PCR, PFGE and MLSA revealed differences in banding patterns, also DNA-DNA hybridization values were well below 70% confirming W5^T to be a new species. DNA G+C content was 46.7 mol%. Major fatty acids were iso-C15:0, iso-C17:0, iso-C17:1 ω9c, iso-C13:0 3OH, iso-C11:0 3OH and C16:0. Polar lipids included phosphatidylglycerol (PG) and phosphatidylethanolamine (PE) diphosphatidylglycerol (DPG) phospholipid (PL) two aminolipids (AL) and two unidentified lipids (L1-2). Q-8 is the predominant ubiquinone. On the basis of polyphasic taxonomic study, strain W5^T is considered to be representative of a new species of the genus Idiomarina, for which the name Idiomarina andamanensis sp. nov. is being proposed. The type strain W5^T (= LMG 29773^T = JCM 31645^T) was isolated from Andaman Sea.

Source water quality shaping different fouling scenarios in a full-scale desalination plant at the Red Sea

The complexity of Reverse Osmosis (RO) membrane fouling phenomenon has been widely studied and several factors influencing it have been reported by many researchers. This original study involves the investigation of two different fouling profiles produced at a seawater RO desalination plant installed on a floating mobile barge. The plant was moved along the coastline of the Red Sea in Saudi Arabia. The two locations where the barge was anchored showed different water quality. At the second location, two modules were harvested. One of the modules was pre-fouled by inorganics during plant operation at the previous site while the other was installed at the second site. Fouled membranes were subjected to a wide range of chemical and microbiological characterization procedures. Drastically different fouling patterns were observed in the two membranes which indicates the influence of source water quality on membrane surface modification and on fouling of RO membranes.

Pseudorhodobacter antarcticus sp. nov., isolated from Antarctic intertidal sandy sediment, and emended description of the genus Pseudorhodobacter Uchino et al. 2002 emend. Jung et al. 2012

A Gram-negative, aerobic, non-motile, pink-pigmented and rod-shaped strain, designated ZS3-33(T), was isolated from Antarctic intertidal sandy sediment. The strain grew optimally at 15 °C and with 1.0 % (w/v) NaCl. It reduced nitrate to nitrite and hydrolysed Tween 20. It could not produce bacteriochlorophyll a. The predominant cellular fatty acid was C18 : 1ω7c and the predominant respiratory quinone was Q-10. The major polar lipids were phosphatidylglycerol, phosphatidylcholine, two unidentified aminophospholipids and an unidentified aminolipid. Analyses of 16S rRNA gene sequences revealed that strain ZS3-33(T) belonged to the genus Pseudorhodobacter, showing 97.4 % similarity to the type strain of Pseudorhodobacter ferrugineus and 95.3 % similarity to the type strain of Pseudorhodobacter aquimaris. Levels of gyrB gene sequence similarity between strain ZS3-33(T) and the type strains of P. ferrugineus and P. aquimaris were 87.6 and 81.7 %, respectively. DNA-DNA relatedness between strain ZS3-33(T) and P. ferrugineus DSM 5888(T) was 56.6 %. The genomic DNA G+C content of strain ZS3-33(T) was 57.1 mol%. Based on data from this polyphasic study, strain ZS3-33(T) represents a novel species of the genus Pseudorhodobacter, for which the name Pseudorhodobacter antarcticus sp. nov. is proposed. The type strain is ZS3-33(T) ( = CGMCC 1.10836(T) = KCTC 23700(T)). An emended description of the genus Pseudorhodobacter Uchino et al. 2002 emend. Jung et al. 2012 is also proposed.

Idiomarina maris sp. nov., a marine bacterium isolated from sediment

A protease-producing marine bacterium, designated CF12-14T, was isolated from sediment of the South China Sea. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain CF12-14T formed a separate lineage within the genus Idiomarina (Gammaproteobacteria). The isolate showed the highest 16S rRNA gene sequence similarity with Idiomarina salinarum ISL-52T (94.7 %), Idiomarina seosinensis CL-SP19T (94.6 %) and other members of the genus Idiomarina (91.9–94.6 %). Cells were Gram-negative, aerobic, flagellated, straight or slightly curved, and often formed buds and prosthecae. Strain CF12-14T grew at 4–42 °C (optimum 30–35 °C) and with 0.1–15 % (w/v) NaCl (optimum 2–3 %). The isolate reduced nitrate to nitrite and hydrolysed DNA, but did not produce acids from sugars. The predominant cellular fatty acids were iso-C15 : 0 (27.4 %), iso-C17 : 0 (16.0 %) and iso-C17 : 1ω9c (15.8 %). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The major respiratory quinone was ubiquinone 8. The DNA G+C content was 50.4 mol%. The phylogenetic, phenotypic and chemotaxonomic data supported the conclusion that CF12-14T represents a novel species of the genus Idiomarina, for which the name Idiomarina maris sp. nov. is proposed. The type strain is CF12-14T ( = CCTCC AB 208166T = KACC 13974T).

Aliidiomarina taiwanensis gen. nov., sp. nov., isolated from shallow coastal water

A Gram-negative, heterotrophic, aerobic, marine bacterium, designated AIT1T, was isolated from a seawater sample collected in the shallow coastal region of Bitou Harbour, New Taipei City, Taiwan. Cells grown in broth cultures were straight or slightly curved rods that were motile by means of a single polar flagellum. Strain AIT1T required NaCl for growth, grew optimally at 30–40 °C and with 1.5–5.0 % NaCl, and was incapable of anaerobic growth by fermentation of glucose or other carbohydrates. The isoprenoid quinones consisted of Q-8 (95.2 %) and Q-9 (4.8 %). The major polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The cellular fatty acids were predominantly iso-branched and included iso-C17 : 0 (26.5 %), summed feature 9 (comprising iso-C17 : 1ω9c and/or 10-methyl C16 : 0; 25.9 %) and iso-C15 : 0 (20.5 %). The DNA G+C content was 51.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain AIT1T formed a distinct lineage within the class Gammaproteobacteria and was most closely related to members of the genus Idiomarina in the family Idiomarinaceae (91.5–93.9 % 16S rRNA gene sequence similarity). The phylogenetic data, together with chemotaxonomic, physiological and morphological data, revealed that the isolate should be classified as a representative of a novel species in a new genus in the family Idiomarinaceae, for which the name Aliidiomarina taiwanensis gen. nov., sp. nov. is proposed. The type strain is AIT1T ( = JCM 16052T = BCRC 80035T = NCCB 100321T).

Aliidiomarina haloalkalitolerans sp. nov., a marine bacterium isolated from coastal surface seawater

A novel Gram-negative, rod shaped, motile, non-sporing strictly aerobic bacterium, designated strain AK5(T), was isolated from a sea water sample collected near Visakhapatnam coast, Bay of Bengal, India. Colonies on marine agar were circular, 3-4 mm in diameter, creamish and rose with entire margin. Growth occurred at 10-40°C, 0.5-12% (w/v) NaCl and pH of 7-11. Strain AK5(T) was oxidase and catalase positive. The fatty acids were dominated by iso-branched saturated and unsaturated fatty acids with a high abundance of iso-C(15:0), iso-C(17:0) and summed feature 9 (as defined by MIDI). Q8 was found to be the major respiratory quinone and diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and four unidentified phospholipids as polar lipids. The DNA G+C content of strain AK5(T) was 54.7 ± 0.2 mol%. Phylogenetic analysis revealed that strain AK5(T) was a member of the genus Aliidiomarina and closely related to Aliidiomarina taiwanensis with a phylogenetic distance of 5.3% (94.7% 16S rRNA gene sequence similarity) and clustered with the same species. Results from the polyphasic taxonomy study support the conclusion that strain AK5(T) represents a novel Aliidiomarina species, for which the name Aliidiomarina haloalkalitolerans sp. nov. is proposed. The type strain of A. haloalkalitolerans is AK5(T) (= MTCC 11064(T) = JCM 17359(T)).

Idiomarina aquimaris sp. nov., isolated from the reef-building coral Isopora palifera

A bacterial strain designated SW15(T) was isolated from a sample of the reef-building coral Isopora palifera, collected in southern Taiwan. The novel strain was characterized using a polyphasic taxonomic approach. Cells of strain SW15(T) were Gram-negative, aerobic, light yellow, rod-shaped and motile by means of a single polar flagellum. In phylogenetic analyses based on 16S rRNA gene sequences, strain SW15(T) appeared to belong to the genus Idiomarina in the class Gammaproteobacteria and to be most closely related to Idiomarina homiensis PO-M2(T) (97.6% sequence similarity). Strain SW15(T) exhibited optimal growth between 20 and 30 °C, with NaCl between 3% and 4% (w/v) and at a pH value between 7 and 8. Predominant cellular fatty acids were iso-C(15:0) (31.1%), iso-C(17:0) (15.4%), iso-C(17:1)ω9c (10.0%) and C(16:0) (8.8%). The major respiratory quinone was ubiquinone Q-8. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylserine, an uncharacterized aminolipid and several uncharacterized phospholipids. The DNA G+C content was 51.1 mol%. The level of DNA-DNA relatedness between strain SW15(T) and Idiomarina homiensis PO-M2(T) was 42.6-56.5%. The results of physiological and biochemical tests allowed the clear phenotypic differentiation of the novel strain from established species of the genus Idiomarina. Based on the genotypic, phenotypic and chemotaxonomic data, strain SW15(T) represents a novel species in the genus Idiomarina, for which the name Idiomarina aquimaris sp. nov. is proposed, with SW15(T) (=LMG 25374(T)=BCRC 80083(T)) as the type strain.

Myroides phaeus sp. nov., isolated from human saliva, and emended descriptions of the genus Myroides and the species Myroides profundi Zhang et al. 2009 and Myroides marinus Cho et al. 2011

A novel bacterial strain, designated MY15T, was isolated from a saliva sample taken from a student during a teaching experiment in China. Phylogenetic analyses based on 16S rRNA gene sequences showed that the novel strain was most closely related to Myroides marinus JS-08T, Myroides odoratimimus LMG 4029T and Myroides profundi D25T with 96.5 %, 96.3 % and 96.1 % gene sequence similarities, respectively, demonstrating that the novel strain belonged to the genus Myroides. Strain MY15T formed pale yellow colonies that turned to brown on Luria-Bertani (LB) agar and that gave off a characteristic fruity odour. Cells were Gram-staining-negative, rod-shaped and non-motile. The new isolate contained menaquinone 6 (MK-6) as the major respiratory quinone and C15:0 iso (51.2 %), C17:0 iso 3-OH (12.9 %) and C13:0 iso (10.5 %) as the dominant fatty acids. The G+C content of the DNA was 34.3 mol%. On the basis of this study, based on a polyphasic taxonomic approach, strain MY15T (=DSM 23313T=LMG 25566T) represents a novel species of the genus Myroides, for which the name Myroides phaeus sp. nov. is proposed. Emended descriptions of the genus Myroides and of the species M. profundi and M. marinus are also given.

Purification and characterization of a bifunctional alginate lyase from Pseudoalteromonas sp. SM0524

An alginate lyase-producing bacterial strain, Pseudoalteromonas sp. SM0524, was screened from marine rotten kelp. In an optimized condition, the production of alginate lyase from Pseudoalteromonas sp. SM0524 reached 62.6 U/mL, suggesting that strain SM0524 is a good producer of alginate lyases. The bifunctional alginate lyase aly-SJ02 secreted by strain SM0524 was purified. Aly-SJ02 had an apparent molecular mass of 32 kDa. The optimal temperature and pH of aly-SJ02 toward sodium alginate was 50 °C and 8.5, respectively. The half life period of aly-SJ02 was 41 min at 40 °C and 20 min at 50 °C. Aly-SJ02 was most stable at pH 8.0. N-terminal sequence analysis suggested that aly-SJ02 may be an alginate lyase of polysaccharide lyase family 18. Aly-SJ02 showed activities toward both polyG (α-l-guluronic acid) and polyM (β-D-mannuronic acid), indicating that it is a bifunctional alginate lyase. Aly-SJ02 had lower K(m) toward polyG than toward polyM and sodium alginate. Thin layer chromatography and ESI-MS analyses showed that aly-SJ02 mainly released dimers and trimers from polyM and alginate, and trimers and tetramers from polyG, which suggests that aly-SJ02 may be a good tool to produce dimers and trimers from alginate.

Pseudidiomarina aestuarii sp. nov., a marine bacterium isolated from shallow coastal seawater

A non-motile, rod-shaped and aerobic marine bacterium, designated strain KYW314(T), was isolated from seawater collected from the South Sea, Republic of Korea. Cells were Gram-negative, catalase- and oxidase-positive and had proteolytic activity. The major fatty acids were iso-C(15 : 0) (17.2 %), C(16 : 0) (11.1 %), iso-C(17 : 0) (10.5 %) and C(18 : 1)ω 7c (10.0 %). The DNA G+C content was 56.4 mol%. A phylogenetic tree based on 16S rRNA gene sequences showed that strain KYW314(T) formed a lineage within the genus Pseudidiomarina (95.4-97.3 % sequence similarity) and a distinct branch within the clade containing Pseudidiomarina taiwanensis PIT1(T) and Pseudidiomarina sediminum c121(T). Phenotypic characteristics could distinguish strain KYW314(T) from members of the genus Pseudidiomarina. On the basis of the data presented, strain KYW314(T) represents a novel species, for which the name Pseudidiomarina aestuarii sp. nov. is proposed. The type strain is KYW314(T) (=KCTC 22740(T) =JCM 16344(T)).

Description of Idiomarina insulisalsae sp. nov., isolated from the soil of a sea salt evaporation pond, proposal to transfer the species of the genus Pseudidiomarina to the genus Idiomarina and emended description of the genus Idiomarina

A halophilic, aerobic Gram-negative bacterium, designated strain CVS-6(T), was isolated from a sea salt evaporation pond on the Island of Sal in the Cape Verde Archipelago. Phylogenetic analysis of the 16S rRNA gene sequence revealed a clear affiliation of the organism with members of the family Idiomarinaceae. Sequence similarities between CVS-6(T) and the type strains of the species of the genera Pseudidiomarina and Idiomarina ranged from 93.7% to 96.9%. The major isoprenoid quinone was ubiquinone 8 (Q-8). The major cellular fatty acids were 15:0 iso (21.8%), 17:0 iso (12.5%), 17:1 iso omega9c (10.7%), and 16:1 omega7c (10.6%). The DNA G+C content was 51.6 mol%. The species represented by strain CVS-6(T) could be distinguished from the species of the genera Pseudidiomarina and Idiomarina; however, it was not possible to distinguish both genera from each other using the phenotypic or chemotaxonomic characteristics examined. Consequently, we propose that the species classified in the genus Pseudidiomarina should be transferred to the genus Idiomarina. We also propose that, on the basis of physiological and biochemical characteristics, strain CVS-6(T) (=LMG 23123=CIP 108836) represents a new species which we name Idiomarina insulisalsae.

Pseudidiomarina marina sp. nov. and Pseudidiomarina tainanensis sp. nov. and reclassification of Idiomarina homiensis and Idiomarina salinarum as Pseudidiomarina homiensis comb. nov. and Pseudidiomarina salinarum comb. nov., respectively

Two Gram-negative strains of heterotrophic, aerobic, marine bacteria, designated PIM1T and PIN1T, were isolated from seawater samples collected from the shallow coastal region of An-Ping Harbour, Tainan, Taiwan. Cells grown in broth cultures were straight rods and non-motile. The two isolates required NaCl for growth and grew optimally at 30-35 degrees C and 2-5 % NaCl. They grew aerobically and were not capable of anaerobic growth by fermentation of glucose or other carbohydrates. The cellular fatty acids were predominantly iso-branched, with iso-C(15 : 0) (17.0-21.4 %), iso-C(17 : 0) (18.2-21.0 %) and iso-C(17 : 1)omega9c (15.7-16.6 %) as the most abundant components. The predominant isoprenoid quinone was Q-8 (95.2-97.1 %). Strains PIM1T and PIN1T had DNA G+C contents of 46.6 and 46.9 mol%, respectively. Phylogeny based on 16S rRNA gene sequences and DNA-DNA hybridization, together with data from physiological, morphological and chemotaxonomic characterizations, indicated that the two isolates should be classified as representatives of two novel species of the genus Pseudidiomarina of the family Idiomarinaceae, for which the names Pseudidiomarina marina sp. nov. (type strain PIM1T=BCRC 17749T=JCM 15083T) and Pseudidiomarina tainanensis sp. nov. (type strain PIN1T=BCRC 17750T=JCM 15084T) are proposed. In addition, based on the characterization data obtained in this study, it is proposed that Idiomarina homiensis and Idiomarina salinarum should be reclassified as Pseudidiomarina homiensis comb. nov. and Pseudidiomarina salinarum comb. nov., respectively.