A hyperstable, low-salt adapted protease from halophilic archaeon with potential applications in salt-fermented foods.

Salt-tolerant proteases with remarkable stability are highly desirable biocatalysts in the salt-fermented food industry. In this study, the undigested autocleavage product of HlyA (halolysin A), a low-salt adapted halolysin from halophilic archaeon Halococcus salifodinae, was investigated. HlyA underwent autocleavage of its C-terminal extension (CTE) at temperatures over 40 °C or NaCl concentrations below 2 M to yield HlyAΔCTE. HlyAΔCTE demonstrated robust stability over a wide range of -20-60 °C, 0.5-4 M NaCl, and pH 6.0-10.0 for at least 72 h. Notably, HlyAΔCTE is the first reported halolysin with such exceptional stability. Compared with HlyA, HlyAΔCTE preferred high temperatures (50-75 °C), low salinities (0.5-2.5 M NaCl), and near-neutral (pH 6.5-8.0) conditions to achieve high activity, consistently with its production conditions. HlyAΔCTE displayed a higher Vmax value against azocasein than HlyA. During fish sauce fermentation, HlyAΔCTE significantly enhanced fish protein hydrolysis, indicating its potential as a robust biocatalyst in the salt-fermented food industry.

Halobacterium yunchengense sp. nov., Natronomonas amylolytica sp. nov., Halorientalis halophila sp. nov., Halobellus salinisoli sp. nov., halophilic archaea isolated from a saline lake and inland saline soil.

Four halophilic archaeal strains YCN1T, YCN58T, LT38T, and LT62T were isolated from Yuncheng Salt Lake (Shanxi, China) and Tarim Basin (Xinjiang, China), respectively. Phylogenetic and phylogenomic analyses showed that these four strains tightly cluster with related species of Halobacterium, Natronomonas, Halorientalis, and Halobellus, respectively. The AAI, ANI, and dDDH values between these four strains and their related species of respective genera were lower than the proposed threshold values for species delineation. Strains YCN1T, YCN58T, LT38T, and LT62T could be differentiated from the current species of Halobacterium, Natronomonas, Halorientalis, and Halobellus, respectively, based on the comparison of diverse phenotypic characteristics. The polar lipid profiles of these four strains were closely similar to those of respective relatives within the genera Halobacterium, Natronomonas, Halorientalis, and Halobellus, respectively. The phenotypic, phylogenetic, and genome-based analyses indicated that strains YCN1T, YCN58T, LT38T, and LT62T represent respective novel species within the genera Halobacterium, Natronomonas, Halorentalis, and Halobellus, for which the names Halobacterium yunchengense sp. nov., Natronomonas amylolytica sp. nov., Halorientalis halophila sp. nov., and Halobellus salinisoli sp. nov. are proposed, respectively.

Predicting CD27 expression and clinical prognosis in serous ovarian cancer using CT-based radiomics.

BACKGROUND: This study aimed to develop and evaluate radiomics models to predict CD27 expression and clinical prognosis before surgery in patients with serous ovarian cancer (SOC). METHODS: We used transcriptome sequencing data and contrast-enhanced computed tomography images of patients with SOC from The Cancer Genome Atlas (n = 339) and The Cancer Imaging Archive (n = 57) and evaluated the clinical significance and prognostic value of CD27 expression. Radiomics features were selected to create a recursive feature elimination-logistic regression (RFE-LR) model and a least absolute shrinkage and selection operator logistic regression (LASSO-LR) model for CD27 expression prediction. RESULTS: CD27 expression was upregulated in tumor samples, and a high expression level was determined to be an independent protective factor for survival. A set of three and six radiomics features were extracted to develop RFE-LR and LASSO-LR radiomics models, respectively. Both models demonstrated good calibration and clinical benefits, as determined by the receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis. The LASSO-LR model performed better than the RFE-LR model, owing to the area under the curve (AUC) values of the ROC curves (0.829 vs. 0.736). Furthermore, the AUC value of the radiomics score that predicted the overall survival of patients with SOC diagnosed after 60 months was 0.788 using the LASSO-LR model. CONCLUSION: The radiomics models we developed are promising noninvasive tools for predicting CD27 expression status and SOC prognosis. The LASSO-LR model is highly recommended for evaluating the preoperative risk stratification for SOCs in clinical applications.

Niraparib maintenance therapy using an individualised starting dose in patients with platinum-sensitive recurrent ovarian cancer (NORA): final overall survival analysis of a phase 3 randomised, placebo-controlled trial.

Background: Niraparib significantly prolonged progression-free survival versus placebo in patients with platinum-sensitive, recurrent ovarian cancer (PSROC), regardless of germline BRCA mutation (gBRCAm) status, in NORA. This analysis reports final data on overall survival (OS). Methods: This randomised, double-blind, placebo-controlled, phase 3 trial enrolled patients across 30 centres in China between 26 September 2017 and 2 February 2019 (clinicaltrials.gov, NCT03705156). Eligible patients had histologically confirmed, recurrent, (predominantly) high-grade serous epithelial ovarian cancer, fallopian tube carcinoma, or primary peritoneal carcinoma (no histological restrictions for those with gBRCAm) and had received ≥2 prior lines of platinum-based chemotherapy. Patients were randomised (2:1) to receive niraparib or placebo, with stratification by gBRCAm status, time to recurrence following penultimate platinum-based chemotherapy, and response to last platinum-based chemotherapy. Following a protocol amendment, the starting dose was individualised: 200 mg/day for patients with bodyweight <77 kg and/or platelet count <150 × 103/µL at baseline and 300 mg/day otherwise. OS was a secondary endpoint. Findings: Totally, 265 patients were randomised to receive niraparib (n = 177) or placebo (n = 88), and 249 (94.0%) received an individualised starting dose. As of 14 August 2023, median follow-up for OS was 57.9 months (IQR, 54.8-61.6). Median OS (95% CI) with niraparib versus placebo was 51.5 (41.4-58.9) versus 47.6 (33.3-not evaluable [NE]) months, with hazard ratio [HR] of 0.86 (95% CI, 0.60-1.23), in the overall population; 56.0 (36.1-NE) versus 47.6 (31.6-NE) months, with HR of 0.86 (95% CI, 0.46-1.58), in patients with gBRCAm; and 46.5 (41.0-NE) versus 46.9 (31.8-NE) months, with HR of 0.87 (95% CI, 0.56-1.35), in those without. No new safety signals were identified, and myelodysplastic syndromes/acute myeloid leukaemia occurred in three (1.7%) niraparib-treated patients. Interpretation: Niraparib maintenance therapy with an individualised starting dose demonstrated a favourable OS trend versus placebo in PSROC patients, regardless of gBRCAm status. Funding: Zai Lab (Shanghai) Co., Ltd; National Major Scientific and Technological Special Project for "Significant New Drugs Development" in 2018, China [grant number 2018ZX09736019].

Halomarina litorea sp. nov., Halomarina pelagica sp. nov., Halomarina halobia sp. nov., and Halomarina ordinaria sp. nov., Halophilic Archaea Isolated from Coastal and Inland Saline Soil.

Four halophilic archaeal strains, BCD28T, BND7T, PSR21T, and PSRA2T, were isolated from coastal and inland saline soil, respectively. The 16S rRNA and rpoB' gene sequence similarities among these four strains and current species of Halomarina were 95.9-96.6% and 86.9-90.3%, respectively. Phylogenetic and phylogenomic analyses revealed that these four strains tightly cluster with the current species of the genus Halomarina. The AAI, ANI, and dDDH values among these four strains and current species of Halomarina were 65.3-68.4%, 75.8-77.7%, and 20.3-22.0%, respectively, clearly below the threshold values for species demarcation. Strains BCD28T, BND7T, PSR21T, and PSRA2T could be differentiated from the current species of Halomarina based on the comparison of diverse phenotypic characteristics. The major polar lipids of these four strains were phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), and four to five glycolipids. Phosphatidylglycerol sulfate (PGS) was only detected in strain BND7T. The phenotypic, phylogenetic, and genome-based analyses suggested that strains BCD28T (= CGMCC 1.18776T = JCM 34908T), BND7T (= CGMCC 1.18778T = JCM 34910T), PSR21T (= CGMCC 1.17027T = JCM 34147T), and PSRA2T (= CGMCC 1.17214T = JCM 34148T) represent four novel species of the genus Halomarina, for which the names Halomarina litorea sp. nov., Halomarina pelagica sp. nov., Halomarina halobia sp. nov., and Halomarina ordinaria sp. nov. are proposed.

Plasmodium vivax tryptophan-rich antigen reduces type I collagen secretion via the NF-κBp65 pathway in splenic fibroblasts.

BACKGROUND: The spleen plays a critical role in the immune response against malaria parasite infection, where splenic fibroblasts (SFs) are abundantly present and contribute to immune function by secreting type I collagen (collagen I). The protein family is characterized by Plasmodium vivax tryptophan-rich antigens (PvTRAgs), comprising 40 members. PvTRAg23 has been reported to bind to human SFs (HSFs) and affect collagen I levels. Given the role of type I collagen in splenic immune function, it is important to investigate the functions of the other members within the PvTRAg protein family. METHODS: Protein structural prediction was conducted utilizing bioinformatics analysis tools and software. A total of 23 PvTRAgs were successfully expressed and purified using an Escherichia coli prokaryotic expression system, and the purified proteins were used for co-culture with HSFs. The collagen I levels and collagen-related signaling pathway protein levels were detected by immunoblotting, and the relative expression levels of inflammatory factors were determined by quantitative real-time PCR. RESULTS: In silico analysis showed that P. vivax has 40 genes encoding the TRAg family. The C-terminal region of all PvTRAgs is characterized by the presence of a domain rich in tryptophan residues. A total of 23 recombinant PvTRAgs were successfully expressed and purified. Only five PvTRAgs (PvTRAg5, PvTRAg16, PvTRAg23, PvTRAg30, and PvTRAg32) mediated the activation of the NF-κBp65 signaling pathway, which resulted in the production of inflammatory molecules and ultimately a significant reduction in collagen I levels in HSFs. CONCLUSIONS: Our research contributes to the expansion of knowledge regarding the functional role of PvTRAgs, while it also enhances our understanding of the immune evasion mechanisms utilized by parasites.

Novel Archaeal Histamine Oxidase from Natronobeatus ordinarius: Insights into Histamine Degradation for Enhancing Food Safety.

Histamine, found abundantly in salt-fermented foods, poses a risk of food poisoning. Natronobeatus ordinarius, a halophilic archaeon isolated from a salt lake, displayed a strong histamine degradation ability. Its histamine oxidase (HOD) gene was identified (hodNbs). This is the first report of an archaeal HOD. The HODNbs protein was determined to be a tetramer with a molecular weight of 307 kDa. HODNbs displayed optimum activity at 60-65 °C, 1.5-2.0 M NaCl, and pH 6.5. Notably, within the broad NaCl range between 0.5 and 2.5 M, HODNbs retained above 50% of its maximum activity. HODNbs exhibited good thermal stability, pH stability, and salinity tolerance. HODNbs was able to degrade various biogenic amines. The Vmax of HODNbs for histamine was 0.29 µmol/min/mg, and the Km was 0.56 mM. HODNbs exhibited high efficiency in histamine removal from fish sauce, namely, 100 µg of HODNbs degraded 5.63 mg of histamine (37.9%) in 10 g of fish sauce within 24 h at 50 °C. This study showed that HODNbs with excellent enzymatic properties has promising application potentials to degrade histamine in high-salt foods.

Effect of laser beam incidence angle on weld formation mechanism and corrosion resistance of T2 copper/304 stainless steel.

Over the last 20 years, industry interest in copper has increased. Its application in the petrochemical, automotive, and nuclear power industries highlights the need for new research directions especially in the joining of copper to other metals. In this work, lap joint of 304 stainless steel and T2 copper precoated with Cu-Mn-Ni filler metal was performed by laser brazing. The aim of this study is to characterize the influence of laser beam incidence angle on the welded joint forming mode, microstructure, elements diffusion and corrosion resistance. According to the findings, the joint is classified as a welded joint when the laser beam incidence angle is 80°, and as a welded-brazed joint when it's 90°, 70°, or 60°. The microstructure is mainly composed of Cu-rich and Fe-rich phases, Mn in the Cu-rich phase aggregation and Cr in the Fe-rich phase aggregation. In the fusion zone (FZ) the content of less than 50% of the liquid will be in the form of supersaturated droplets in the matrix of the other side. The local corrosion pair that the copper steel matrix and liquid drop produce in the FZ speeds up the dissolution of the Cu-rich phase, which effected corrosion resistance of the joint.

Proposed minimal standards for description of new taxa of the class Halobacteria.

Halophilic archaea of the class Halobacteria are the most salt-requiring prokaryotes within the domain Archaea. In 1997, minimal standards for the description of new taxa in the order Halobacteriales were proposed. From then on, the taxonomy of the class Halobacteria provides an excellent example of how changing concepts on prokaryote taxonomy and the development of new methods were implemented. The last decades have witnessed a rapid expansion of the number of described taxa within the class Halobacteria coinciding with the era of genome sequencing development. The current members of the International Committee on Systematics of Prokaryotes Subcommittee on the Taxonomy of Halobacteria propose these revisions to the recommended minimal standards and encourage the use of advanced technologies in the taxonomic description of members of the Halobacteria. Most previously required and some recommended minimal standards for the description of new taxa in the class Halobacteria were retained in the present revision, but changes have been proposed in line with the new methodologies. In addition to the 16S rRNA gene, the rpoB' gene is an important molecular marker for the identification of members of the Halobacteria. Phylogenomic analysis based on concatenated conserved, single-copy marker genes is required to infer the taxonomic status of new taxa. The overall genome relatedness indexes have proven to be determinative in the classification of the taxa within the class Halobacteria. Average nucleotide identity, digital DNA-DNA hybridization, and average amino acid identity values should be calculated for rigorous comparison among close relatives.

Postmenopausal endometrial non-benign lesion risk classification through a clinical parameter-based machine learning model.

OBJECTIVE: This study aimed to develop and evaluate a machine learning model utilizing non-invasive clinical parameters for the classification of endometrial non-benign lesions, specifically atypical hyperplasia (AH) and endometrioid carcinoma (EC), in postmenopausal women. METHODS: Our study collected clinical parameters from a cohort of 999 patients with postmenopausal endometrial lesions and conducted preprocessing to identify 57 relevant characteristics from these irregular clinical data. To predict the presence of postmenopausal endometrial non-benign lesions, including atypical hyperplasia and endometrial cancer, we employed various models such as eXtreme Gradient Boosting (XGBoost), Random Forest (RF), Logistic Regression (LR), Support Vector Machine (SVM), Back Propagation Neural Network (BPNN), as well as two ensemble models. Additionally, a test set was performed on an independent dataset consisting of 152 patients. The performance evaluation of all models was based on metrics including the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, precision, and F1 score. RESULTS: The RF model demonstrated superior recognition capabilities for patients with non-benign lesions compared to other models. In the test set, it attained a sensitivity of 88.1% and an AUC of 0.93, surpassing all alternative models evaluated in this study. Furthermore, we have integrated this model into our hospital's Clinical Decision Support System (CDSS) and implemented it within the outpatient electronic medical record system to continuously validate and optimize its performance. CONCLUSIONS: We have trained a model and deployed a system with high discriminatory power that may provide a novel approach to identify patients at higher risk of postmenopausal endometrial non-benign lesions who may benefit from more tailored screening and clinical intervention.

Genome-based classification of the family Haloferacaceae and description of five novel species of Halobaculum.

The taxonomic status of some species of Halobellus, Haloferax, Halogranum, and Haloplanus within the family Haloferacaceae was elucidated by phylogenetic, phylogenomic, and comparative genomic analyses. The relative species of each genus should constitute a single species based on the overall genome-related indexes proposed for species demarcation. The cutoff values of AAI (72.1%), ANI (82.2%), and rpoB' gene similarity (90.7%) were proposed to differentiate genera within the family Haloferacaceae. According to these standards, a novel genus related to the genus Halobaculum was proposed to accommodate Halobaculum halophilum Gai3-2 T and Halobaculum salinum NJ-3-1 T. Five halophilic archaeal strains, DT31T, DT55T, DT92T, SYNS20T, and YSMS11T, isolated from a tidal flat and a marine solar saltern in China, were subjected to polyphasic classification. The phenotypic, phylogenetic, phylogenomic, and comparative genomic analyses revealed that strains DT31T (= CGMCC 1.18923 T = JCM 35417 T), DT55T (= CGMCC 1.19048 T = JCM 36147 T), DT92T (= CGMCC 1.19057 T = JCM 36148 T), SYNS20T (= CGMCC 1.62628 T = JCM 36154 T), and YSMS11T (= CGMCC 1.18927 T = JCM 34912 T) represent five novel species of the genus Halobaculum, for which the names, Halobaculum lipolyticum sp. nov., Halobaculum marinum sp. nov., Halobaculum litoreum sp. nov., Halobaculum halobium sp. nov., and Halobaculum limi sp. nov., are proposed.

Genome-based classification of genera Halosegnis and Salella, and description of four novel halophilic archaea isolated from a tidal flat.

The current species of Halosegnis and Salella within the class Halobacteria are closely related based on phylogenetic, phylogenomic, and comparative genomic analyses. The Halosegnis species showed 99.8-100.0% 16S rRNA and 96.6-99.6% rpoB' gene similarities to the Salella species, respectively. Phylogenetic and phylogenomic analyses showed that Salella cibi CBA1133T, the sole species of Salella, formed a single tight cluster with Halosegnis longus F12-1T, then with Halosegnis rubeus F17-44T. The average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), and average amino acid identity (AAI) values between Salella cibi CBA1133T and Halosegnis longus F12-1T were 99.2, 94.2, and 98.6%, respectively, much higher than the thresholds for species demarcation. This genome-based classification revealed that the genus Salella should be merged with Halosegnis, and Salella cibi should be a later heterotypic synonym of Halosegnis longus. Halophilic archaeal strains DT72T, DT80T, DT85T, and DT116T, isolated from the saline soil of a tidal flat in China, were subjected to polyphasic taxonomic characterization. The phenotypic, chemotaxonomic, phylogenetic, and phylogenomic features indicated that strains DT72T (= CGMCC 1.18925T = JCM 35418T), DT80T (= CGMCC 1.18926T = JCM 35419T), DT85T (= CGMCC 1.19049T = JCM 35605T), and DT116T (= CGMCC 1.19045T = JCM 35606T) represent four novel species of the genera Halorussus, Halosegnis and Haloglomus, respectively, for which the names, Halorussus caseinilyticus sp. nov., Halorussus lipolyticus sp. nov., Halosegnis marinus sp. nov., and Haloglomus litoreum sp. nov., are proposed.

Halomontanus rarus gen. nov., sp. nov., a novel halophilic archaeon of the family Natrialbaceae from salt lakes on the Qinghai-Xizang Plateau.

Two halophilic archaeal strains TS33T and KZCA124 were isolated from two distant salt lakes on the Qinghai-Xizang Plateau, respectively. Culture-independent analysis indicated that these two strains were original inhabitants but low abundant taxa in respective salt lakes. Strains TS33T and KZCA124 were able to grow at 20-60 °C (optimum were 42 and 35 °C, respectively), with 0.9-4.8 M NaCl (optimum were 3.0 and 2.6 M, respectively), with 0-0.7 M MgCl2 (optimum, 0.3 M) and at pH 5.0-9.5 (optimum were pH 7.5 and pH 7, respectively). The 16S rRNA and rpoB' gene similarities between these two strains were 99.7% and 99.4%, and these two similarities among strains TS33T, KZCA124, and existing species of the family Natrialbaceae were 90.6-95.5% and 84.4-89.3%, respectively. Phylogenetic and phylogenomic analyses indicated that strains TS33T and KZCA124 formed an independent branch separated from neighboring genera, Saliphagus, Natronosalvus, and Natronobiforma. The averagenucleotideidentity (ANI), digital DNA-DNAhybridization (dDDH), and average amino acid identity (AAI) values between strains TS33T and KZCA124 were 96.4%, 73.1%, and 96.7%, respectively, higher than the thresholds for species demarcation. The overall genome-related indexes between these two strains and existing species of family Natrialbaceae were 73-77%, 21-25%, and 63-70%, respectively, significantly lower than the species boundary thresholds. Strains TS33T and KZCA124 may represent a novel species of a new genus within the family Natrialbaceae judged by the cutoff value of AAI (≤76%) proposed to differentiate genera within the family Natrialbaceae. The major polar lipids of strains TS33T and KZCA124 were phosphatidic acid, phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, sulfated mannosyl glucosyl diether, and sulfated galactosyl mannosyl glucosyl diether. These two strains could be distinguished from the related genera according to differential phenotypic characteristics. These phenotypic, phylogenetic, and genomic analyses revealed that strains TS33T (=KCTC 4310T = MCCC 4K00132T) and KZCA124 (=CGMCC 1.17432 = JCM 34316) represent a novel species of a new genus of the family Natrialbaceae and were named Halomontanus rarus gen. nov., sp. nov.

Prognostic value of left ventricular trabeculae fractal analysis in patients with dilated cardiomyopathy.

BACKGROUND: The prognostic value of left ventricular (LV) myocardial trabecular complexity on cardiovascular magnetic resonance (CMR) in dilated cardiomyopathy (DCM) remains unknown. This study aimed to evaluate the prognostic value of LV myocardial trabecular complexity using fractal analysis in patients with DCM. METHODS: Consecutive patients with DCM who underwent CMR between March 2017 and November 2021 at two hospitals were prospectively enrolled. The primary endpoints were defined as the combination of all-cause death and heart failure hospitalization. The events of cardiac death alone were defined as the secondary endpoints.LV trabeculae complexity was quantified by measuring the fractal dimension (FD) of the endocardial border based on fractal geometry on CMR. Cox proportional hazards regression and Kaplan-Meier survival analysis were used to examine the association between variables and outcomes. The incremental prognostic value of FD was assessed in nested models. RESULTS: A total of 403 patients with DCM (49.31 ± 14.68 years, 69% male) were recruited. After a median follow-up of 43 months (interquartile range, 28-55 months), 87 and 24 patients reached the primary and secondary endpoints, respectively. Age, heart rate, New York Heart Association functional class >II, N-terminal pro-B-type natriuretic peptide, LV ejection fraction, LV end-diastolic volume index, LV end-systolic volume index, LV mass index, presence of late gadolinium enhancement, global FD, LV mean apical FD, and LV maximal apical FD were univariably associated with the outcomes (all P < 0.05). After multivariate adjustment, LV maximal apical FD remained a significant independent predictor of outcome [hazard ratio = 1.179 (1.116, 1.246), P < 0.001]. The addition of LV maximal apical FD in the nested models added incremental prognostic value to other common clinical and imaging risk factors (all <0.001; C-statistic: 0.84-0.88, P < 0.001). CONCLUSION: LV maximal apical FD was an independent predictor of the adverse clinical outcomes in patients with DCM and provided incremental prognostic value over conventional clinical and imaging risk factors.

Genome-based taxonomy of genera Haloarcula and Halomicroarcula, and description of six novel species of Haloarcula.

The genera Haloarcula and Halomicroarcula are the most closely related genera within the family Haloarculaceae (class Halobacteria). The respective 16S rRNA genes of type strains from the genus Haloarcula showed 94.7-96.5% similarities to their homologous genes of type strains from the genus Halomicroarcula. The Haloarcula species showed 89.3-92.8% rpoB' gene similarities to Halomicroarcula species. These similarities were higher than the proposed genus boundary. Phylogenomic analysis revealed that these two genera formed a tight cluster separated from Halomicrobium with high bootstrap confidence. The average amino acid identity (AAI) values among Haloarcula and Halomicroarcula were 70.1-74.5%, higher than the cutoff value (67.0%) to differentiate the genera Haloarcula and Halomicroarcula from Halomicrobium. These results indicated that the genus Halomicroarcula should be merged with Haloarcula. Then, six novel species are described based on strains DFY41T, GDY20T, SHR3T, XH51T, YJ-61-ST, and ZS-22-S1T isolated from coarse sea salt, marine solar saltern, and salt lake (China). These six strains formed separate clades (90.1-99.3% 16S rRNA and 89.0-94.9% rpoB' gene similarities) and then clustered with current Haloarcula and Halomicroarcula species (89.4-99.1% 16S rRNA and 87.6-95.0% rpoB' gene similarities), as revealed by phylogenetic analyses. The average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), and AAI values among these six strains and current Haloarcula and Halomicroarcula species were 76.2-89.8%, 25.3-46.0%, and 70.3-89.7%, respectively, clearly below the species demarcation threshold. These six strains were distinguished from current Haloarcula and Halomicroarcula species according to differential phenotypic characteristics. Six novel species, Haloarcula halophila sp. nov., Haloarcula litorea sp. nov., Haloarcula rara sp. nov., Haloarcula halobia sp. nov., Haloarcula pelagica sp. nov., and Haloarcula ordinaria sp. nov., are proposed to accommodate strains DFY41T, GDY20T, SHR3T, XH51T, YJ-61-ST, and ZS-22-S1T, respectively.

Halospeciosus flavus gen. nov., sp. nov. and Haladaptatus caseinilyticus sp. nov., halophilic archaea isolated from saline soil of an inland solar saltern and offshore sediment.

Two novel halophilic archaeal strains (XZGYJ-43T and ZJ1T) were isolated from Mangkang ancient solar saltern (Tibet, PR China) and Zhujiang river inlet (Guangdong, PR China), respectively. The comparison of the 16S rRNA gene sequences revealed that strain XZGYJ-43T is related to the current species of the family Halobacteriaceae (89.2-91.7% similarity) and strain ZJ1T showed 94.7-98.3% similarity to the current species of the genus Haladaptatus. Phylogenetic analyses based on 16S rRNA genes, rpoB' genes and genomes indicated that strain XZGYJ-43T is separate from the related genera, Halocalculus, Salarchaeum and Halarchaeum of the family Halobacteriaceae, and strain ZJ1T tightly clusters with the current species of the genus Haladaptatus. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values between strain XZGYJ-43T and the current species of the family Halobacteriaceae were 71-75, 20-25 and 59-68 %, and these values between strain ZJ1T and the current species of the genus Haladaptatus were 77-81, 27-32 and 76-82 %, respectively, clearly below the thresholds for prokaryotic species demarcation. These two strains could be distinguished from their relatives according to differential phenotypic characteristics. The major polar lipids of strain XZGYJ-43T were phosphatidic acid (PA), phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), mannosyl glucosyl diether (DGD-1; DGD-PA) and sulphated mannosyl glucosyl diether (S-DGD-1; S-DGD-PA), and those of strain ZJ1T were PA, PG, PGP-Me, DGD-PA, S-DGD-1 (S-DGD-PA) and sulphated galactosyl mannosyl glucosyl diether. Based on phenotypic, phylogenetic and genomic data, strain XZGYJ-43T (=CGMCC 1.13890T=JCM 33735T) represents a novel species of a new genus within the family Halobacteriaceae, and strain ZJ1T (=CGMCC 1.18785T=JCM 34917T) represents a novel species of the genus Haladaptatus, for which the names Halospeciosus flavus gen. nov., sp. nov. and Haladaptatus caseinilyticus sp. nov. are proposed, respectively.

Halomicrococcus gelatinilyticus sp. nov. and Halosimplex aquaticum sp. nov., halophilic archaea isolated from saline soil and an inland solar saltern.

Two extremely halophilic archaeal strains, GSLN9T and XZYJT29T, were isolated from the saline soil in different regions of western China. Both strains GSLN9T and XZYJT29T have two 16S rRNA genes with similarities of 95.1 and 94.8 %, respectively. Strain GSLN9T was mostly related to the genus Halomicrococcus based on 16S rRNA (showing 91.0-96.0 % identities) and rpoB' genes (showing 92.0 % identity). Strain XZYJT29T showed 92.1-97.6 % (16S rRNA gene) and 91.4-93.1 % (rpoB' gene) sequence similarities to its relatives in the genus Halosimplex, respectively. The polar lipid profile of strain GSLN9T included phosphatidic acid (PA), phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), phosphatidylglycerol sulphate (PGS), sulphated mannosyl glucosyl diether (S-DGD-1) and sulphated galactosyl mannosyl glucosyl diether (S-TGD-1), mostly similar to that of Halomicrococcus hydrotolerans H22T. PA, PG, PGP-Me, S-DGD-1 (S-DGD-PA), S2-DGD, S-TGD-1 and an unidentified glycolipid were detected in strain XZYJT29T; this polar lipid composition is similar to those of members of the genus Halosimplex. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values between these two strains and their relatives of the genera Halomicrococcus and Halosimplex were no more than 82, 27 and 80 %, respectively, much lower than the thresholds for species demarcation. Other phenotypic characterization results indicated that strains GSLN9T and XZYJT29T can be differentiated from the current species of the genera Halomicrococcus and Halosimplex, respectively. These results revealed that strains GSLN9T (=CGMCC 1.15215T=JCM 30842T) and XZYJT29T (=CGMCC 1.15828T=JCM 31853T) represent novel species of Halomicrococcus and Halosimplex, for which the names Halomicrococcus gelatinilyticus sp. nov. and Halosimplex aquaticum sp. nov. are proposed.