Effect of Model-Based Iterative Reconstruction on Image Quality of Chest Computed Tomography for COVID-19 Pneumonia.

PURPOSE: This study aimed to compare the image quality of chest computed tomography (CT) scans for COVID-19 pneumonia using forward-projected model-based iterative reconstruction solution-LUNG (FIRST-LUNG) with filtered back projection (FBP) and hybrid iterative reconstruction (HIR). METHOD: The CT images of 44 inpatients diagnosed with COVID-19 pneumonia between December 2022 and June 2023 were retrospectively analyzed. The CT images were reconstructed using FBP, HIR, and FIRST-LUNG-MILD/STANDARD/STRONG. The CT values and noise of the lumen of the main trachea and erector spine muscle were measured for each group. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective evaluations included overall image quality, noise, streak artifact, visualization of normal lung structures, and abnormal CT features. One-way analysis of variance was used to compare the objective and subjective indicators among the five groups. The task-based transfer function was derived for three distinct contrasts representing anatomical structures, lower-contrast lesion, and higher-contrast lesion. RESULTS: The results of the study demonstrated significant differences in image noise, SNR, and CNR among the five groups (P < 0.001). The FBP images exhibited the highest levels of noise and the lowest SNR and CNR among the five groups (P < 0.001). When compared to the FBP and HIR groups, the noise was lower in the FIRST-LUNG-MILD/STANDARD/STRONG group, while the SNR and CNR were higher (P < 0.001). The subjective overall image quality score of FIRST-LUNG-MILD/STANDARD was significantly better than FBP and FIRST-LUNG-STRONG (P < 0.001). FIRST-LUNG-MILD was superior to FBP, HIR, FIRST-LUNG-STANDARD, and FIRST-LUNG-STRONG in visualizing proximal and peripheral bronchovascular and subpleural vessels (P < 0.05). Additionally, FIRST-LUNG-MILD achieved the best scores in evaluating abnormal lung structure (P < 0.001). The overall interobserver agreement was substantial (intraclass correlation coefficient = 0.891). The task-based transfer function 50% values of FIRST reconstructions are consistently higher compared to FBP and HIR. CONCLUSIONS: The FIRST-LUNG-MILD/STANDARD algorithm can enhance the image quality of chest CT in patients with COVID-19 pneumonia, while preserving important details of the lesions, better than the FBP and HIR algorithms. After evaluating various COVID-19 pneumonia lesions and considering the improvement in image quality, we recommend using the FIRST-LUNG-MILD reconstruction for diagnosing COVID-19 pneumonia.

Magnetic-field-induced splitting of Rydberg Electromagnetically Induced Transparency and Autler-Townes spectra in 87Rb vapor cell.

We theoretically and experimentally investigate the Rydberg electromagnetically induced transparency (EIT) and Autler-Townes (AT) splitting of 87Rb vapor under the combined influence of a magnetic field and a microwave field. In the presence of static magnetic field, the effect of the microwave field leads to the dressing and splitting of each mF state, resulting in multiple spectral peaks in the EIT-AT spectrum. A simplified analytical formula was developed to explain the EIT-AT spectrum in a static magnetic field, and the theoretical calculations agree qualitatively with experimental results. The Rydberg atom microwave electric field sensor performance was enhanced by making use of the splitting interval between the two maximum absolute mF states separated by the static magnetic field, which was attributed to the stronger Clebsch-Gordon coefficients between the extreme mF states and the frequency detuning of the microwave electric field under the static magnetic field. The traceable measurement limit of weak electric field by EIT-AT splitting method was extended by an order of magnitude, which is promising for precise microwave electric field measurement.

Precise measurement of microwave polarization using a Rydberg atom-based mixer.

A Rydberg atom-based mixer has opened up a new method to characterize microwave electric fields such as the precise measurement of their phase and strength. This study further demonstrates, theoretically and experimentally, a method to accurately measure the polarization of a microwave electric field based on a Rydberg atom-based mixer. The results show that the amplitude of the beat note changes with the polarization of the microwave electric field in a period of 180 degrees, and in the linear region a polarization resolution better than 0.5 degree can be easily obtained which reaches the best level by a Rydberg atomic sensor. More interestingly, the mixer-based measurements are immune to the polarization of the light field that forms the Rydberg EIT. This method considerably simplifies theoretical analysis and the experimental system required for measuring microwave polarization using Rydberg atoms and is of interest in microwave sensing.

Frequency stabilization method for transition to a Rydberg state using Zeeman modulation.

We herein develop and demonstrate a stable frequency-locking scheme for Rydberg atomic experiments. We use the Zeeman effect to modulate the three-level ladder-type Rydberg electromagnetically induced transparency (EIT) signal to lock the laser frequency of the coupling light for transition from its intermediate state to a Rydberg state. The effects of polarization of the probe and coupling lights, and the amplitude of the AC modulated magnetic field ${{\boldsymbol B}_0}$B0 on the EIT and the corresponding dispersive error signal, are both analyzed. The results show that both the EIT signal and dispersive error signal are the strongest when the polarizations of coupling and probe fields are circular and equal. The signal-to-noise ratio of the dispersive error signal increases with ${{\boldsymbol B}_0}$B0. The slope of the dispersive error signal increases first and then decreases with ${{\boldsymbol B}_0}$B0, which is related to the increase of the EIT linewidth caused by the higher ${{\boldsymbol B}_0}$B0. The linewidth of the laser is significantly less than 500 kHz after frequency locking, which satisfies the requirements of most experiments involving Rydberg atoms. The method proposed herein can generally be applied to any cascade system of Rydberg atoms.

Dispersive microwave electrometry using Zeeman frequency modulation spectroscopy of electromagnetically induced transparency in Rydberg atoms.

We herein developed and demonstrated a Zeeman frequency modulation scheme for improving the signal-to-noise ratio of microwave electric field measurement using Rydberg atoms. The spectra of the electromagnetically induced transparency (EIT) and Autler-Townes splitting of Rydberg atoms is frequency modulated by an alternating current magnetic field. The signal-to-noise ratio of the corresponding dispersive error signal is enhanced more than 10 times than that of the original spectrum. Furthermore, we show that the slope of the dispersive error signal near the resonance of the Rydberg EIT can be used to characterize the weak microwave electric field amplitudes. The more intuitive and simpler structure compared with other existing frequency modulation technologies greatly reduces the difficulties of experiments and experimental data analysis.

Prokaryotic Community Structure Driven by Salinity and Ionic Concentrations in Plateau Lakes of the Tibetan Plateau.

The prokaryotic community composition and diversity and the distribution patterns at various taxonomic levels across gradients of salinity and physiochemical properties in the surface waters of seven plateau lakes in the Qaidam Basin, Tibetan Plateau, were evaluated using Illumina MiSeq sequencing. These lakes included Lakes Keluke (salinity, <1 g/liter), Qing (salinity, 5.5 to 6.6 g/liter), Tuosu (salinity, 24 to 35 g/liter), Dasugan (salinity, 30 to 33 g/liter), Gahai (salinity, 92 to 96 g/liter), Xiaochaidan (salinity, 94 to 99 g/liter), and Gasikule (salinity, 317 to 344 g/liter). The communities were dominated by Bacteria in lakes with salinities of <100 g/liter and by Archaea in Lake Gasikule. The clades At12OctB3 and Salinibacter, previously reported only in hypersaline environments, were found in a hyposaline lake (salinity, 5.5 to 6.6 g/liter) at an abundance of ∼1.0%, indicating their ecological plasticity. Salinity and the concentrations of the chemical ions whose concentrations covary with salinity (Mg(2+), K(+), Cl(-), Na(+), SO4 (2-), and Ca(2+)) were found to be the primary environmental factors that directly or indirectly determined the composition and diversity at the level of individual clades as well as entire prokaryotic communities. The distribution patterns of two phyla, five classes, five orders, five families, and three genera were well predicted by salinity. The variation of the prokaryotic community structure also significantly correlated with the dissolved oxygen concentration, pH, the total nitrogen concentration, and the PO4 (3-) concentration. Such correlations varied depending on the taxonomic level, demonstrating the importance of comprehensive correlation analyses at various taxonomic levels in evaluating the effects of environmental variable factors on prokaryotic community structures. Our findings clarify the distribution patterns of the prokaryotic community composition in plateau lakes at the levels of individual clades as well as whole communities along gradients of salinity and ionic concentrations.

Psychroflexus salis sp. nov. and Psychroflexus planctonicus sp. nov., isolated from a salt lake.

Two Gram-stain-negative, catalase- and oxidase-positive, strictly aerobic, non-motile, moderately halophilic bacteria (strains X15M-6T and X15M-8T) were isolated from Lake Xiaochaidan, a salt lake in Qaidam basin, Qinghai Province, China. Cells of X15M-6T were rod-like or coccoid, 0.5-0.9 µm wide and 0.9-1.5 µm long; cells of X15M-8T were rods, 0.3-0.6 µm wide and 1.2-2.2 µm long. Growth was observed in the presence of 0.5-14.0 % (w/v) NaCl (optimum, 3.0 %) and at pH 6.5-10.0 (optimum, pH 7.0-7.5) for both. X15M-6T and X15M-8T grew at 10-35 °C (optimum, 20-25 °C) and 4-35 °C (optimum, 25 °C), respectively. Both contained iso-C15 : 0, anteiso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids, phosphatidylethanolamine and an unknown lipid as the major polar lipids, and menaquinone MK-6 as the major respiratory quinone. The DNA G+C contents were 32.8 and 35.0 mol% for X15M-6T and X15M-8T, respectively. Phylogenetic trees based on 16S rRNA gene sequences showed that both strains belonged to the genus Psychroflexus and formed a separate lineage. In addition, strains X15M-6T and X15M-8T shared 96.8 % 16S rRNA gene sequence similarity and showed highest similarities to members of the genus Psychroflexus (92.7-93.5 and 91.8-93.1 %, respectively). Based on the above data, it is concluded that strains X15M-6T and X15M-8T represent two novel species of the genus Psychroflexus, for which the names Psychroflexus salis sp. nov. (type strain X15M-6T = CGMCC 1.12925T = JCM 30615T) and Psychroflexus planctonicus sp. nov. (type strain X15M-8T = CGMCC 1.12931T = JCM 30616T) are proposed.

Planktosalinus lacus gen. nov., sp. nov., a member of the family Flavobacteriaceae isolated from a salt lake.

A Gram-staining-negative bacterium, strain X14M-14T, was isolated from a salt lake (Lake Xiaochaidan) in Qaidam basin, Qinghai Province, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain X14M-14T were non-spore-forming, non-motile rods. Strain X14M-14T was strictly heterotrophic and aerobic, catalase-positive and oxidase-negative. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain X14M-14T belonged to the family Flavobacteriaceae and formed a distinct lineage that was independent of the most closely related genera: Aequorivita (16S rRNA gene sequence similarities, 91.8-93.1 %) and Salinimicrobium (91.5-92.4 %). Strain X14M-14T contained MK-6 as the major respiratory quinone, and phosphatidylethanolamine and two unknown lipids as the major polar lipids. The major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. The presence of iso-C15 : 1 G as a predominant fatty acid could distinguish this strain clearly from the most closely related genera in the family Flavobacteriaceae. The DNA G+C content was 36.6 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain X14M-14T represents a novel genus and species of the family Flavobacteriaceae, for which the name Planktosalinus lacus gen. nov., sp. nov. is proposed. The type strain is X14M-14T ( = CGMCC 1.12924T = KCTC 42675T).

Aquisalinus flavus gen. nov., sp. nov., a member of the family Parvularculaceae isolated from a saline lake.

A Gram-stain-negative bacterium, strain D11M-2T, was isolated from a saline lake (Lake Dasugan) in Qaidam basin, Qinghai Province, China. Its taxonomic position was determined by using a polyphasic approach. Cells were non-spore-forming rods, 0.5-0.7 µm wide and 1.2-1.6 µm long, and motile by means of a single subpolar or lateral flagellum. Strain D11M-2T was strictly heterotrophic and aerobic, and catalase- and oxidase-positive. Growth was observed in the presence of 0-14.0% (w/v) NaCl (optimum, 2.0%), and at 10-35 °C (optimum, 30 °C) and pH 6.0-10.5 (optimum, pH 8.0). Strain D11M-2T contained Q-10 and Q-11 as the respiratory quinones and three unknown glycolipids as the major polar lipids. The major cellular fatty acids (>10.0%) were summed feature 8 (C18:1ω7c and/or C18:1ω6c) and C16:0. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain D11M-2T belonged to the family Parvularculaceae and formed a separate lineage that was independent of the two genera within the family Parvularculaceae. Strain D11M-2T exhibited 92.8-93.4% 16S rRNA gene sequence similarity to members of the genus Parvularcula (highest to Parvularcula bermudensis HTCC 2503T), and 90.2% to a member of the genus Amphiplicatus. The DNA G+C content was 59 mol% (Tm). Based on the phenotypic, chemotaxonomic and phylogenetic data, strain D11M-2T is considered to represent a novel species of a new genus in the family Parvularculaceae, for which the name Aquisalinus flavus gen. nov., sp. nov. is proposed. The type strain of Aquisalinus flavus is D11M-2T (=CGMCC 1.12921T=KCTC 42673T).

Lacimicrobium alkaliphilum gen. nov., sp. nov., a member of the family Alteromonadaceae isolated from a salt lake.

A Gram-stain-negative, facultatively aerobic bacterium, strain X13M-12T, was isolated from a salt lake (Lake Xiaochaidan) in the Qaidam basin, Qinghai Province, PR China. Cells of strain X13M-12T were slightly curved, rod-shaped, 0.5-0.8 µm wide and 1.2-2.3 µm long, and motile by means of a polar flagellum. Strain X13M-12T was catalase- and oxidase-positive. Growth was observed in the presence of 0-15.0 % (w/v) NaCl (optimum 3.0-5.0 %), and at 4-40 °C (optimum 25-30 °C) and pH 6.0-11.0 (optimum pH 8.5). Strain X13M-12T contained Q-8 as the sole respiratory quinone, and phosphatidylglycerol and phosphatidylethanolamine as the major polar lipids. The major cellular fatty acids (>10 % of totals) were C16 : 0, C16 : 1ω7c and/or C16 : 1ω6c, and C18 : 1ω7c and/or C18 : 1ω6c. Phylogenetic analysis, based on 16S rRNA gene sequences, showed that strain X13M-12T belonged to the family Alteromonadaceae and formed a distinct lineage, showing low gene sequence similarities to closely related genera: Bowmanella, Aestuariibacter and Salinimonas (16S rRNA gene sequence similarities, 93.0-93.1 %, 92.3-93.1 % and 92.6-92.7 %, respectively). In addition, strain X13M-12T showed < 92.7 % gene sequence similarities to other species of the family Alteromonadaceae. The DNA G+C content of strain X13M-12T was 49 mol% (Tm). Based on the data presented above, strain X13M-12T is considered to represent a novel genus and species of the family Alteromonadaceae, for which the name Lacimicrobium alkaliphilum gen. nov., sp. nov. is proposed. The type strain is X13M-12T ( = CGMCC 1.12923T = KCTC 42674T).

[Bacterial community characterization of rearing water of marine recirculating aquaculture systems for yellow grouper (Epinephelus awoara)].

OBJECTIVE: This study was aimed to reveal the bacterial community characteristics of rearing water of marine recirculating aquaculture system for yellow grouper (Epinephelus awoara), and compare the differences between bacterial community structure of healthy rearing water and sick rearing water in order to elucidate the relationship between bacterial community and fish disease. METHODS: The next generation sequencing method was used, and the bacterial community structure and α-diversity indices (species richness, species evenness and phylogenetic diversity) between the rearing water of healthy and diseased groups were studied and compared. In addition, the traditional cultivation method was used to isolate suspected pathogens from the niduses of diseased yellow groupers. RESULTS: There was no significant difference between the α-diversities of healthy and diseased rearing water bodies, however, the results of principal coordinates analysis (PCoA) and the sample clustering of heatmap showed that the bacterial communities of healthy and diseased rearing water bodies were quite different. Although phyla Proteobacteria, Verrucomicrobia and Bacteroidetes were all the predominant ones in both communities, their relative abundance varied greatly. In diseased community, the relative abundances of α-Proteobacteria (25.07%) and γ-Protebacteria (22.74%) were similar, whereas the proportion of γ-Protebacteria (40.49%) was much higher than α-Proteobacteria (10.87%) in the healthy community. The differences of Verrucomicrobia and Bacteroidetes between the healthy and the diseased rearing water were also significant with relative abundances of 10.9% and 26.4%, and 20.9% and 12.3%, respectively. The significantly different families were Rhodobacteraceae and Rhodospirillaceae within class α-Proteobacteria; Alteromonadaceae and HTCC2188 within class γ-Protebacteria; Verrucomicrobiaceae within Verrucomicrobia; Cryomorphaceae within Bacteroidetes. The healthy and the diseased communities owned specific core microbes themselves. Glaciecola, HTCC, Sediminicola and Prevotella were the core genera in healthy rearing water, and Vibrio, Rubritalea and Oleibacter in diseased rearing water. Twenty strains of Vibrio spp. and one of Acinetobacter haemolyticus were isolated from skin, liver and spleen of diseased yellow grouper. CONCLUSION: The shift of bacterial community structure and relative abundance of rearing water will help monitor the healthy status of recirculating aquaculture system. Our study provides theory and experimental basis to diagnosis and monitor of Vibrio disease for yellow grouper recirculating aquaculture system.

Maritimibacter lacisalsi sp. nov., isolated from a salt lake, and emended description of the genus Maritimibacter Lee et al. 2007.

A Gram-staining-negative, non-motile, strictly aerobic bacterium, strain X12M-4T, was isolated from Xiaochaidan Lake, a salt lake (salinity 9.9 %, w/w) in Qaidam basin, Qinghai Province, China. Its taxonomic position was determined by using a polyphasic approach. Strain X12M-4T was catalase- and oxidase-positive. Cells were rod-shaped, 0.5­0.8 µm wide and 1.1­1.6 µm long. Growth was observed in the presence of 0­11.0 % (w/v) NaCl (optimum, 5.0­6.0 %) and at 15­40 °C (optimum, 25 °C) and pH 6.5­9.5 (optimum, pH 7.0). No growth occurred at 10 °C or 45 °C. Strain X12M-4T contained C18 : 1ω7c, C19 : 0 cyclo ω8c and C16 : 0 as the major fatty acids (>10.0 %). The predominant respiratory quinone was Q-10.The major polar lipids were phosphatidylcholine, phosphatidylglycerol, diphosphatidglycerol, an unknown aminolipid and an unidentified lipid. The DNA G+C content was 65.7 mol% (determined using T m). Strain X12M-4T showed highest 16S rRNA gene sequence similarities to Maritimibacter alkaliphilus HTCC2654T (96.7 %), Roseibacterium elongatum DSM 19469T (96.4 %), Tropicimonas aquimaris DPG-21T (95.6 %), 'Roseibacterium beibuensis' JLT1202r (95.6 %) and Tropicimonas sediminicola M97T (95.5 %) and < 95.5 % to others. Phylogenetic trees based on 16S rRNA gene sequences indicated that strain X12M-4T formed a robust cluster with M. alkaliphilus HTCC2654T. On the basis of the data, it is concluded that strain X12M-4T represents a novel species of the genus Maritimibacter, for which the name Maritimibacter lacisalsi sp. nov. is proposed. The type strain is X12M-4T ( = CGMCC 1.12922T = JCM 30555T). To accommodate the novel species, the description of the genus Maritimibacter was emended.

Thalassotalea marina sp. nov., isolated from a marine recirculating aquaculture system, reclassification of Thalassomonas eurytherma as Thalassotalea eurytherma comb. nov. and emended description of the genus Thalassotalea.

A Gram-stain-negative, facultatively anaerobic bacterium, strain QBLM2T, was isolated from rearing water of a marine recirculating aquaculture system in Tianjin, China. Its taxonomic position was investigated through a polyphasic approach. Cells of strain QBLM2T were non-spore-forming rods, motile by means of a single polar flagellum. Positive for oxidase and catalase. Growth occurred at 15-40 °C (optimum 30 °C), at pH 6.5-10.5 (optimum pH 7.5-8.5) and in the presence of 0-5.0 % (w/v) NaCl (optimum 3 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain QBLM2T formed a distinct lineage within the genus Thalassotalea and exhibited sequence similarities of 94.5-96.3 % to members of the genus Thalassotalea. The predominant fatty acids (>10 %) were C17 : 1ω8c and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The major polar lipids were phosphatidylglycerol and phosphatidylethanolamine. Ubiquinone 8 (Q-8) was the major ubiquinone. The DNA G+C content was 37.1 mol%. Based on the data above, strain QBLM2T is considered to represent a novel species of the genus Thalassotalea, for which the name Thalassotalea marina sp. nov. is proposed. The type strain is QBLM2T ( = CGMCC 1.12814T = KCTC 42731T). Phylogenetic analyses indicated that Thalassomonas eurytherma Za6a-12T fell within the genus Thalassotalea, so it is reclassified as Thalassotalea eurytherma comb. nov. and the description of the genus Thalassotalea is emended.

Lacimonas salitolerans gen. nov., sp. nov., isolated from surface water of a saline lake.

A Gram-stain-negative bacterium, strain TS-T30T, was isolated from a saline lake (Lake Tuosu) in Qaidam basin, Qinghai province, China, and its taxonomic position was determined by using a polyphasic approach. Cells were non-spore-forming rods, non-motile, 0.8-1.4 µm wide and 1.9-4.0 µm long. Strain TS-T30T was strictly heterotrophic and aerobic. Catalase- and oxidase-positive. Growth was observed in the presence of 0.5-11.0 % (w/v) NaCl (optimum 3.0 %), and at 10-35 °C (optimum 25 °C) and pH 6.5-10.0 (optimum pH 8.5). Strain TS-T30T contained C18 : 1ω7c as the only predominant fatty acid. The major respiratory quinone was Q-10. The DNA G+C content was 62 mol% (Tm). Phylogenetic trees based on 16S rRNA gene sequences showed that strain TS-T30T formed a distinct lineage that was independent of other most closely related genera: Lutimaribacter (95.2-95.9 % 16S rRNA gene sequence similarities), Poseidonocella (95.4 %), Ruegeria (92.8-94.9 %), Marivita (93.6-94.9 %), Seohaeicola (94.7 %), Sediminimonas (94.7 %), Shimia (93.9-94.7 %), Oceanicola (92.6-94.5 %) and Roseicyclus (94.5 %). The major polar lipids were phosphatidylglycerol, one unidentified phospholipid and an unknown aminolipid; phosphatidylcholine was not detected. These data demonstrated that strain TS-T30T represents a novel species of a new genus in the family Rhodobacteraceae, for which the name Lacimonas salitolerans gen. nov., sp. nov. is proposed. The type strain of the type species is TS-T30T ( = CGMCC 1.12477T = NBRC 110969T).

Marinobacter halophilus sp. nov., a halophilic bacterium isolated from a salt lake.

A Gram-staining-negative bacterium, strain XCD-X12(T), was isolated from Xiaochaidan Lake, a salt lake (salinity 9.9%, w/w) in Qaidam basin, Qinghai Province, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain XCD-X12(T) were non-spore-forming rods, 0.4-0.7 µm wide, 2.1-3.2 µm long and motile with a single polar flagellum. Strain XCD-X12(T) was strictly aerobic and catalase- and oxidase-positive. Growth was observed in the presence of 0-20.0% (w/v) NaCl (optimum, 4.0-8.0%), at 4-35 °C (optimum, 30 °C) and at pH 6.5-10.5 (optimum, pH 8.5). It contained Q-9 as the predominant respiratory quinone. The major fatty acids (>10.0%) were C16 : 0, C16 : 1ω9c and C18 : 1ω9c. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two unknown phospholipids and an uncharacterized aminophospholipid. The DNA G+C content was 55.6 mol% (Tm). Phylogenetic trees based on 16S rRNA gene sequences showed that strain XCD-X12(T) was associated with the genus Marinobacter, and showed the highest 16S rRNA gene sequence similarity to Marinobacter hydrocarbonoclasticus ATCC 49840(T) (97.4%), M. vinifirmus FB1(T) (96.8%), M. excellens KMM 3809(T) (96.8%) and M. antarcticus ZS2-30(T) (96.7%). DNA-DNA relatedness of strain XCD-X12(T) to M. hydrocarbonoclasticus CGMCC 1.7683(T) was 34 ± 5%. Based on these data, it is concluded that strain XCD-X12(T) represents a novel species of the genus Marinobacter, for which the name Marinobacter halophilus sp. nov. is proposed. The type strain is XCD-X12(T) ( = CGMCC 1.12481(T)= JCM 30472(T)).

Belliella aquatica sp. nov., isolated from a saline lake.

A Gram-staining-negative bacterium, strain TS-T86(T), was isolated from Lake Tuosu, a saline lake (salinity 5.4%, w/w) in Qaidam basin, China. Its taxonomic position was determined by using a polyphasic approach. Strain TS-T86(T) was strictly heterotrophic, aerobic and catalase- and oxidase-positive. Cells were non-spore-forming, non-motile rods, 0.4-0.6 µm wide and 1.2-2.3 µm long. Growth was observed in the presence of 0-9.0% (w/v) NaCl (optimum, 2.0%), at 4-35 °C (optimum, 25 °C) and at pH 7.0-10.5 (optimum, pH 8.5-9.0). Strain TS-T86(T) contained MK-7 as the predominant respiratory quinone. The major fatty acids (>10%) were iso-C15 : 1 G, iso-C15 : 0, iso-C17 : 1ω9c, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The polar lipids consisted of phosphatidylethanolamine, an unknown phospholipid, six unidentified aminolipids and two uncharacterized lipids. The DNA G+C content was 35 mol% (T m). Phylogenetic trees based on 16S rRNA gene sequences showed that strain TS-T86(T) was associated with the genus Belliella, and showed the highest sequence similarity to Belliella baltica BA134(T) (98.5 %) and then to Belliella kenyensis No.164(T) (95.7%) and Belliella pelovolcani CC-SAL-25(T) (95.3 %). DNA-DNA relatedness of strain TS-T86(T) to Belliella baltica DSM 15883(T) was 32 ± 3%. It is concluded that strain TS-T86(T) represents a novel species of the genus Belliella, for which the name Belliella aquatica sp. nov. is proposed. The type strain is TS-T86(T) ( = CGMCC 1.12479(T) = JCM 19468(T)).

Vibrio salilacus sp. nov., a new member of the Anguillarum clade with six alleles of the 16S rRNA gene from a saline lake.

A Gram-stain-negative, catalase- and oxidase-positive, facultatively aerobic bacterium, strain DSG-S6T, was isolated from Dasugan Lake (salinity 3.1%, w/w), China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain DSG-S6T were non-spore-forming, slightly bent rods, and motile by means of a single polar flagellum. Growth occurred in the presence of 0-7.0% (w/v) NaCl (optimum, 2.0%), at 4-35 °C (optimum, 30 °C) and at pH 6.0-10.5 (optimum, pH 8.0-8.5). C16 : 0, C18 : 1ω7c and C16 : 1ω7c and/or C16 : 1ω6c were the major fatty acids. Six alleles of the 16S rRNA gene sharing 98.9-99.9  % similarity were detected in strain DSG-S6T, which showed highest 16S rRNA gene sequence similarity to Vibrio aestuarianus ATCC 35048T (97.7 %), then to Vibrio pacinii LMG 19999T (97.6%) and Vibrio metschnikovii CIP 69.14T (96.8%). Multilocus sequence analysis of four housekeeping genes and 16S rRNA genes clearly clustered it as a member of the Anguillarum clade. Mean DNA-DNA relatedness between strain DSG-S6T and V. aestuarianus NBRC 15629T, V. pacinii CGMCC 1.12557T and V. metschnikovii JCM 21189T was 20.6 ± 2.3, 38.1 ± 3.5 and 24.2 ± 2.8%, respectively. The DNA G+C content was 46.8 mol% (Tm). Based on the data, it is concluded that strain DSG-S6T represents a novel species of the genus Vibrio, for which the name Vibrio salilacus sp. nov. is proposed. The type strain is DSG-S6T ( = CGMCC 1.12427T = JCM 19265T).

Pseudomonas salina sp. nov., isolated from a salt lake.

A Gram-staining-negative, facultatively aerobic bacterium, strain XCD-X85(T), was isolated from Xiaochaidan Lake, a salt lake (salinity 9.9%, w/v) in Qaidam basin, Qinghai province, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain XCD-X85(T) were non-endospore-forming rods, 0.4-0.6 µm wide and 1.0-1.6 µm long, and motile by means of a single polar flagellum. Strain XCD-X85(T) was catalase- and oxidase-positive. Growth was observed in the presence of 0-12.0% (w/v) NaCl (optimum, 1.0-2.0%) and at 4-35 °C (optimum, 25-30 °C) and pH 6.5-10.5 (optimum, pH 8.0-8.5). Strain XCD-X85(T) contained (>10%) summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C12 : 0, C16 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the predominant fatty acids. The major respiratory quinone was ubiquinone 9 (Q-9). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 57.4 mol%. Phylogenetic trees based on 16S rRNA gene sequences showed that strain XCD-X85(T) was associated with the genus Pseudomonas, and showed highest 16S rRNA gene sequence similarities to Pseudomonas pelagia CL-AP6(T) (99.0%) and Pseudomonas bauzanensis BZ93(T) (96.8%). DNA-DNA relatedness of strain XCD-X85T to P. pelagia JCM 15562(T) was 19 ± 1%. On the basis of the data presented above, it is concluded that strain XCD-X85(T) represents a novel species of the genus Pseudomonas, for which the name Pseudomonas salina sp. nov. is proposed. The type strain is XCD-X85(T) ( = CGMCC 1.12482(T) = JCM 19469(T)).

Marivita lacus sp. nov., isolated from a saline lake.

A Gram-staining-negative, strictly heterotrophic and aerobic bacterium, strain TS-T44T, was isolated from a saline lake, Tuosu Lake in Qaidam basin, Qinghai province, China. Its taxonomic position was investigated using a polyphasic approach. Cells of strain TS-T44T were non-endospore-forming, non-motile rods, 0.8-1.2 µm wide and 1.2-3.0 µm long. Catalase- and oxidase-positive. Growth occurred in the presence of up to 8 % (w/v) NaCl (optimum, 3.0 %) and at 15-35 °C (optimum, 25 °C) and pH 7.0-10.0 (optimum, pH 7.5-8.5). C18 : 1ω7c was the predominant fatty acid. The major respiratory quinone was Q-10. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid and an unknown lipid. The DNA G+C content was 65.5 mol% [determined from the melting temperature (Tm)]. Phylogenetic trees based on 16S rRNA gene sequences showed that strain TS-T44T was associated with the genus Marivita and showed highest sequence similarity to Marivita cryptomonadis CL-SK44T (97.7 %), Marivita litorea CL-JM1T (97.5 %) and Marivita geojedonensis DPG-138T (97.3 %), and < 97 % to other species. DNA-DNA relatedness of strain TS-T44T to M. cryptomonadis JCM 15447T, M. litorea JCM 15446T and M. geojedonensis KCTC 23882T was 23 ± 3 %, 33 ± 4 % and 35 ± 2 %, respectively. Based on the data presented, it is concluded that strain TS-T44T represents a novel species of the genus Marivita, for which the name Marivita lacus sp. nov. is proposed. The type strain is TS-T44T ( = CGMCC 1.12478T = JCM 19516T).

Cribrihabitans marinus gen. nov., sp. nov., isolated from a biological filter in a marine recirculating aquaculture system.

A Gram-negative bacterium, strain CZ-AM5(T), was isolated from an aerated biological filter in a marine recirculating aquaculture system in Tianjin, China. Its taxonomic position was investigated by using a polyphasic approach. Cells of strain CZ-AM5(T) were non-spore-forming rods, 0.5-0.8 µm wide and 1.2-2.0 µm long, and motile by means of one or two polar or lateral flagella. Strain CZ-AM5(T) was strictly aerobic, heterotrophic, oxidase-negative and catalase-positive. Growth occurred at 15-40 °C (optimum, 30-35 °C), at pH 6.5-10.5 (optimum, pH 7.0-7.5) and in the presence of 0-12.0 % (w/v) NaCl (optimum, 4.0 %). The predominant fatty acid was C18 : 1ω7c (80.3 %). Ubiquinone 10 (Q-10) was the sole respiratory quinone. The polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, an unknown aminolipid, an unknown phospholipid and three unknown lipids. The DNA G+C content was 60.4 mol%. Strain CZ-AM5(T) showed the highest 16S rRNA gene sequence similarity (96.5 %) to Phaeobacter caeruleus LMG 24369(T); it exhibited 16S rRNA gene sequence similarity of 95.0-96.5, 95.2-96.3, 96.2, 94.6-95.7 and 94.8-95.8 % to members of the genera Phaeobacter, Ruegeria, Citreimonas, Leisingera and Donghicola, respectively. However, phylogenetic trees based on 16S rRNA gene sequences showed that strain CZ-AM5(T) did not join any of the above genera, but formed a distinct lineage in the trees. On the basis of phenotypic, chemotaxonomic and phylogenetic analyses, strain CZ-AM5(T) is considered to represent a novel genus and species of the family Rhodobacteraceae, for which the name Cribrihabitans marinus gen. nov., sp. nov. is proposed. The type strain of Cribrihabitans marinus is CZ-AM5(T) ( = CGMCC 1.13219(T) = JCM 19401(T)).