Pathophysiological Relevance and Therapeutic Outlook of GPR43 in Atherosclerosis.

Atherosclerosis (AS) is an inflammatory arterial disorder that occurs due to the deposition of the excessive lipoprotein under the artery intima, mainly including low-density lipoprotein (LDL) and other apolipoprotein B-containing lipoproteins. G protein-coupled receptors (GPCRs) play a crucial role in transmitting signals in physiological and pathophysiological conditions. GPCRs recognize inflammatory mediators, thereby serving as important players during chronic inflammatory processes. It has been demonstrated that free fatty acids can function as ligands for various GPCRs, such as free fatty acid receptor (FFAR)1/GPR40, FFAR2/GPR43, FFAR3/GPR41, FFAR4/GPR120, and the lipid metabolite binding glucose-dependent insulinotropic receptor (GPR119). This review discusses GPR43 and its ligands in the pathogenesis of AS, especially focusing on its distinct role in regulating chronic vascular inflammation, inhibiting oxidative stress, ameliorating endothelial dysfunction and improving dyslipidemia. It is hoped that this review may provide guidance for further studies aimed at GPR43 as a promising target for drug development in the prevention and therapy of AS.

[A new sesquiterpene from Syringa oblata].

In this study, the chemical components of ethanol extract from the aromatic parts of Syringa oblata were systematically separated and purified by silica gel column chromatography, thin layer plate preparation and liquid phase preparation. Combined with ultraviolet analyzer(UV), infrared analyzer(IR), nuclear magnetic resonance analyzer(NMR), high resolution mass spectrometer(HR-ESI-MS), X-ray diffraction and other spectrum technology as well as literature physicochemical data comparison methods for structural identification, a total of 10 compounds were identified. They were identified as oblatanoid D(1),(-)-T-muurolol(2), oblatanoid E-G(3-5), 14-noreudesma-3-hydroxy-3-en-2,9-dione(6), 1-isopropyl-2,7-dimethylnaphthalene(7), isocoradiol(8), α-calacorene(9), cadin-4-en-1-ß-ol(10). Compound 1 is a new sesquiterpene compound that has not been reported, and the other 9 compounds are isolated from S. oblata for the first time. The compound 1 has a significant protective effect on the LPS-induced inflammatory injury model of RAW264.7 cells.

Surface Lattice Modulation through Chemical Delithiation toward a Stable Nickel-Rich Layered Oxide Cathode.

Nickel-rich layered oxides (NLOs) are considered as one of the most promising cathode materials for next-generation high-energy lithium-ion batteries (LIBs), yet their practical applications are currently challenged by the unsatisfactory cyclability and reliability owing to their inherent interfacial and structural instability. Herein, we demonstrate an approach to reverse the unstable nature of NLOs through surface solid reaction, by which the reconstructed surface lattice turns stable and robust against both side reactions and chemophysical breakdown, resulting in improved cycling performance. Specifically, conformal La(OH)3 nanoshells are built with their thicknesses controlled at nanometer accuracy, which act as a Li+ capturer and induce controlled reaction with the NLO surface lattices, thereby transforming the particle crust into an epitaxial layer with localized Ni/Li disordering, where lithium deficiency and nickel stabilization are both achieved by transforming oxidative Ni3+ into stable Ni2+. An optimized balance between surface stabilization and charge transfer is demonstrated by a representative NLO material, namely, LiNi0.83Co0.07Mn0.1O2, whose surface engineering leads to a highly improved capacity retention and excellent rate capability with a strong capability to inhibit the crack of NLO particles. Our study highlights the importance of surface chemistry in determining chemical and structural behaviors and paves a research avenue in controlling the surface lattice for the stabilization of NLOs toward reliable high-energy LIBs.

Point-of-Care Diagnosis on Selenium Nutrition Based on Time-Resolved Fluorometric Glycoaffinity Chromatography.

Given the lack of timely evaluation of the well-received selenium fortification, a neat lateral-flow chromatographic solution was constructed here by using the recently identified urinary selenosugar (Sel) as a strongly indicative marker. As there are no ready-made receptors for this synthetic standard, phenylboronic acid (PBA) esterification and Dolichos biflorus agglutinin (DBA) affinity joined up to pinch and pin down the analyte into a sandwich-type glycol complex. Pilot lectin screening on homemade glycan microarrays verified such a new pairing between dual recognizers as PBA-Sel-DBA with a firm monosaccharide-binding constant. To quell the sample autofluorescence, europium nanoparticles with efficient long-life afterglow were employed as conjugating probes under 1 µs excitation. After systematic process optimizations, the prepared Sel-dipstick achieved swift and sensitive fluorometry over the physiological level of the target from 0.1 to 10 µM with a detection limit down to 0.06 µM. Further efforts were made to eliminate matrix effects from both temperature and pH via an approximate formula. Upon completion, the test strips managed to quantify the presence of Sel in not just imitated but real human urine, with comparable results to those in the references. As far as we know, this would be the first in-house prototype for user-friendly and facile diagnosis of Se nutrition with fair accuracy as well as selectivity. Future endeavors will be invested to model a more traceable Se-supplementary plan based on the rhythmic feedback of Sel excretion.

High-Intensity Focused Ultrasound (Sonablate®) for Prostate Cancer: Preliminary Outcomes in Taiwan.

PURPOSE: We reported preliminary outcomes of high-intensity focused ultrasound (HIFU) [Sonablate®] in the combination of transurethral resection of the prostate for localized prostate cancer in Taiwan. METHODS: Seventy-seven patients using Sonablate® HIFU for localized prostate cancer were enrolled in this study from April 2021 to December 2022. Prostate-specific antigen biochemical recurrence, International Index of Erectile Function (IIEF)-5 scores, International Prostate Symptom Score (IPSS), quality of life (QoL) scores, and postoperative complications were recorded during follow-up. RESULTS: Overall, 19.5% of patients were low-risk, 36.4% were intermediate-risk, and 44.1% were high-risk according to the D'Amico risk classification. The median follow-up was 12.09 ± 5.85 months, and the biochemical-free survival rates for the low-, intermediate-, and high-risk groups were 100% (15/15), 96.4% (27/28), and 79.4% (27/34), respectively. Four patients (5.2%) received salvage radiotherapy and all maintained biochemical-free survival. The mean IPSS and QoL scores before versus after HIFU were 10.4 versus 6.8 (p = 0.003) and 3.2 versus 3.0 (p = 0.096), respectively. There was no statistically significant change in preoperative and postoperative IIEF scores (20.6 vs. 19; p = 0.062) in patients who had an IIEF score of >15 at baseline and received nerve-sparing procedures (subtotal ablation). CONCLUSIONS: The results of Sonablate® HIFU in Taiwan indicated adequate short-term cancer control, excellent potency, and continence preservation. HIFU can achieve improvement of IPSS with low complication rates.

ASO Author Reflections: High-Intensity Focused Ultrasound will Become the Routine Practice for Treatment of Localized Prostate Cancer.

PAST: Most prostate cancers are slow growing and are often diagnosed at an old age, which may result in treatment never being needed. However, definitive treatments such as radical prostatectomy and radiation therapy are often associated with many serious adverse effects, harming the physical and mental health of patients. PRESENT: In recent years, different types of minimally invasive therapy have been developed to achieve cancer control, continence, and even potency preservation, such as high-intensity focused ultrasound (HIFU). HIFU has been proposed for prostate cancer patients to provide an equivalent oncologic result to definitive treatment, with a reduced adverse effect profile, thus increasing the interest in HIFU for the treatment of localized prostate cancer. FUTURE: Sonablate® HIFU performed an outstanding cancer control in treating localized prostate cancer, with low biochemical recurrence and complication rates. As further long-term follow-up data mature, we anticipate the routine application of HIFU for localized prostate cancer within the next few years.

IRE1α: from the function to the potential therapeutic target in atherosclerosis.

Inositol requiring enzyme 1 (IRE1) is generally thought to control the most conserved pathway in the unfolded protein response (UPR). Two isoforms of IRE1, IRE1α and IRE1ß, have been reported in mammals. IRE1α is a ubiquitously expressed protein whose knockout shows marked lethality. In contrast, the expression of IRE1ß is exclusively restricted in the epithelial cells of the respiratory and gastrointestinal tracts, and IRE1ß-knockout mice are phenotypically normal. As research continues to deepen, IRE1α was showed to be tightly linked to inflammation, lipid metabolism regulation, cell death and so on. Growing evidence also suggests an important role for IRE1α in promoting atherosclerosis (AS) progression and acute cardiovascular events through disrupting lipid metabolism balance, facilitating cells apoptosis, accelerating inflammatory responses and promoting foam cell formation. In addition, IRE1α was recognized as novel potential therapeutic target in AS prevention. This review provides some clues about the relationship between IRE1α and AS, hoping to contribute to further understanding roles of IRE1α in atherogenesis and to be helpful for the design of novel efficacious therapeutics agents targeting IRE1α-related pathways.

H2S aids osmotic stress resistance by S-sulfhydration of melatonin production-related enzymes in Arabidopsis thaliana.

KEY MESSAGE: Hydrogen sulfide closed Arabidopsis thaliana stomata by increasing the transcription of melatonin-producing enzymes and the post-translational modification levels to combat osmotic stress. Hydrogen sulfide (H2S) and melatonin (MEL) reportedly have similar functions in many aspects of plant growth, development and stress response. They regulate stomatal movement and enhance drought resistance. However, their physiological relationship is not well understood. Here, their crosstalk involved in osmotic stress resistance in Arabidopsis thaliana was studied. Exogenous H2S and MEL closed stomata under normal or osmotic stress conditions and increased the relative water contents of plants under osmotic stress conditions. At the same time, exogenous H2S and MEL responded to osmotic stress by increasing the content of proline and soluble sugar, and reducing malondialdehyde (MDA) content and relative conductivity. Using mutants in the MEL-associated production of serotonin N-acetyltransferase (snat), caffeic acid O-methyltransferase (comt1) and N-acetylserotonin methyltransferase (asmt), we determined that H2S was partially dependent on MEL to close stomata. Additionally, the overexpression of ASMT promoted stomatal closure. Exogenous H2S increased the transcription levels of SNAT, ASMT and COMT1. Furthermore, exogenous H2S treatments increased the endogenous MEL content significantly. At the post-translational level, H2S sulfhydrated the SNAT and ASMT, but not COMT1, enzymes associated with MEL production. Thus, H2S appeared to promote stomatal closure in response to osmotic stress by increasing the transcription levels of MEL synthesis-related genes and the sulfhydryl modification of the encoded enzymes. These results increased our understanding of H2S and MEL functions and interactions under osmotic stress conditions.

Prognostic value of PD-L1 combined positive score in patients with upper tract urothelial carcinoma.

PURPOSE: Upper tract urothelial carcinoma (UTUC) is relatively rare in Western countries. The impact of programmed death-ligand 1 (PD-L1) expression on UTUC remains unclear because previous studies have focused on bladder UC. We investigated the association of PD-L1 expression with clinicopathological features and prognosis in patients with UTUC. METHODS: We retrospectively reviewed the patients with UTUC that we treated at our institute from 2013 to 2018. In total, 105 patients with UTUC undergoing radical nephroureterectomy were analyzed to evaluate the PD-L1 expression on representative whole-tissue sections using the Combined Positive Score (CPS; Dako 22C3 pharmDx assay). A PD-L1 CPS ≥ 10 was considered positive. RESULTS: Among the 105 UTUC cases, 17.1% exhibited positive PD-L1 expression. A CPS ≥ 10 was significantly associated with higher tumor stage (≥ T2, p = 0.034) and lymph node invasion at diagnosis (p = 0.021). A multivariable analysis indicated that a CPS ≥ 10 was an independent prognostic predictor of shorter cancer-specific survival (hazard ratio [HR] = 4.59, 95% confidence interval [CI] = 1.66 - 12.7, p = 0.003) and overall survival (HR = 2.51, 95% CI = 1.19 - 5.27, p = 0.015). CONCLUSIONS: A PD-L1 CPS ≥ 10 in UTUC was associated with adverse pathological features and independently predicted worse cancer-specific and overall survival.

Bioinformatics Analyses of Potential miRNA-mRNA Regulatory Axis in HBV-related Hepatocellular Carcinoma.

Aims: We aimed to explore the crucial miRNA-mRNA axis through bioinformatics analysis and provide evidences for the development of pathophysiological mechanisms and new therapies for HBV-related HCC. Methods: MiRNA (GSE76903) and mRNA (GSE77509) dataset were used to screen differentially expressed miRNAs (DE-miRNAs) and differentially expressed mRNAs (DE-mRNAs) using R software. Overlapping genes between DE-mRNAs and target genes of DE-miRNAs were identified as candidate genes. Hub genes were obtained via cytohubba analysis. The expression at protein and mRNA levels and prognostic value of hub genes were evaluated based on The Cancer Genome Atlas (TCGA) data. Key miRNA-mRNA axes were constructed according to predicted miRNA-mRNA pairs. MiRNA expression and prognostic role were respectively identified using starBase v3.0 and Kaplan-Meier plotter database. Real-time PCR was performed to verify the expression of crucial miRNAs and mRNAs. Coexpression of crucial miRNA and mRNA were analyzed using starBase v3.0. Results: CDK1, CCNB1, CKS2 and CCNE1 were screened as hub genes, which were significantly upregulated at protein and mRNA levels. These up-regulated hub genes were also significantly associated with poor prognosis. Hsa-mir-195-5p/CDK1, hsa-mir-5589-3p/CCNB1 and hsa-let-7c-3p/CKS2 were screened as critical miRNA-mRNA axes. Critical miRNAs were decreased in HCC, which indicates unfavourable prognosis. QPCR results showed that crucial miRNAs were decreased, whereas critical mRNAs were increased in HBV-related HCC. A reverse relationship between miRNA and mRNA in crucial axis was further verified. Conclusion: This study identified several miRNA-mRNA axes in HBV-related HCC. Hsa-mir-195-5p/CDK1, hsa-mir-5589-3p/CCNB1 and hsa-let-7c-3p/CKS2 might serve as potential prognostic biomarkers and therapeutic targets for HBV-related HCC.

Chemometric QSAR modeling of acute oral toxicity of Polycyclic Aromatic Hydrocarbons (PAHs) to rat using simple 2D descriptors and interspecies toxicity modeling with mouse.

The information of the acute oral toxicity for most polycyclic aromatic hydrocarbons (PAHs) in mammals are lacking due to limited experimental resources, leading to a need to develop reliable in silico methods to evaluate the toxicity endpoint. In this study, we developed the quantitative structure-activity relationship (QSAR) models by genetic algorithm (GA) and multiple linear regression (MLR) for the rat acute oral toxicity (LD50) of PAHs following the strict validation principles of QSAR modeling recommended by OECD. The best QSAR model comprised eight simple 2D descriptors with definite physicochemical meaning, which showed that maximum atom-type electrotopological state, van der Waals surface area, mean atomic van der Waals volume, and total number of bonds are main influencing factors for the toxicity endpoint. A true external set (554 compounds) without rat acute oral toxicity values, and 22 limit test compounds, were firstly predicted along with reliability assessment. We also compared our proposed model with the OPERA predictions and recently published literature to prove the prediction reliability. Furthermore, the interspecies toxicity (iST) models of PAHs between rat and mouse were also established, validated and employed for filling data gap. Overall, our developed models should be applicable to new or untested or not yet synthesized PAHs falling within the applicability domain (AD) of the models for rapid acute oral toxicity prediction, thus being important for environmental or personal exposure risk assessment under regulatory frameworks.

CPF impedes cell cycle re-entry of quiescent lung cancer cells through transcriptional suppression of FACT and c-MYC.

Blockade of cell cycle re-entry in quiescent cancer cells is a strategy to prevent cancer progression and recurrence. We investigated the action and mode of action of CPF mixture (Coptis chinensis, Pinellia ternata and Fructus trichosanthis) in impeding a proliferative switch in quiescent lung cancer cells. The results indicated that CPF impeded cell cycle re-entry in quiescent lung cancer cells by reduction of FACT and c-MYC mRNA and protein levels, with concomitant decrease in H3K4 tri-methylation and RNA polymerase II occupancy at FACT and c-MYC promoter regions. Animals implanted with quiescent cancer cells that had been exposed to CPF had reduced tumour volume/weight. Thus, CPF suppresses proliferative switching through transcriptional suppression of FACT and the c-MYC, providing a new insight into therapeutic target and intervention method in impeding cancer recurrence.

IGRNet: A Deep Learning Model for Non-Invasive, Real-Time Diagnosis of Prediabetes through Electrocardiograms.

The clinical symptoms of prediabetes are mild and easy to overlook, but prediabetes may develop into diabetes if early intervention is not performed. In this study, a deep learning model-referred to as IGRNet-is developed to effectively detect and diagnose prediabetes in a non-invasive, real-time manner using a 12-lead electrocardiogram (ECG) lasting 5 s. After searching for an appropriate activation function, we compared two mainstream deep neural networks (AlexNet and GoogLeNet) and three traditional machine learning algorithms to verify the superiority of our method. The diagnostic accuracy of IGRNet is 0.781, and the area under the receiver operating characteristic curve (AUC) is 0.777 after testing on the independent test set including mixed group. Furthermore, the accuracy and AUC are 0.856 and 0.825, respectively, in the normal-weight-range test set. The experimental results indicate that IGRNet diagnoses prediabetes with high accuracy using ECGs, outperforming existing other machine learning methods; this suggests its potential for application in clinical practice as a non-invasive, prediabetes diagnosis technology.

[Cloning and expression analysis of 5-phosphomevalonate kinase gene (CcPMK) in Cinnamomum camphora].

The 5-phosphomevalonate kinase(PMK) is a key enzyme in mevalonate(MVA) pathway which reversibly catalyzes the phosphorylation of mevalonate 5-phosphate(MVAP) to form mevalonate-5-diphosphate(MVAPP) in the presence of ATP and divalent metal ion such as Mg~(2+). In this research, on the basis of the transciptome database of Cinnamomum camphora, the PMK was cloned by cDNA from C. camphora, and was named CcPMK(GenBank number KU886266). The ORF of CcPMK was composed of 1 545 bp, encoding 514 amino acids. The bioinformatics analysis of CcPMK indicated that the molecular weight of the encoded protein was 56.14 kDa, with a theoretically isoelectric point of 7.64, and there was no signal peptide and transmembrane structure in putative protein. By multiple sequence alignment and phylogenetic tree analysis, we found that similarity between CcPMK and PMK amino acid sequence of other plants was as high as 75%. Among the similar sequences, 45% of them belonged to the alpha helix, while 16% belonged to the beta strand. CcPMK obtained 3 PMK protein family motifs and 1 ATP binding site Gly-Leu-Gly-Ser-Ser-Ala-Ala, and its 3 D structure contained a catalytic pocket structure, proving CcPMK as a member of PMK gene family. The result of phylogenetic tree showed that CcPMK was closely related to monocotyledon plants such as Phonenix dactylifera. The results of the Real-time PCR indicated that the expression level of CcPMK in borneol type was higher than that in linalool type, cineol type, iso-nerolidol type and camphor type. CcPMK expressed highest in roots and lowest in branches. Our results revealed that the expression level of CcPMK was different among five chemical types and different plant tissues, and the research provides foundation for further study of the terpenoids biosynthetic pathway in C. camphora.

Pseudaminobacter arsenicus sp. nov., an arsenic-resistant bacterium isolated from arsenic-rich aquifers.

An arsenic-resistant strain, CB3T, was isolated from arsenic-rich aquifers at the Jianghan Plain in Hubei, China. Phylogenetic and biochemical analysis suggested that it should represent a new species of the genus Pseudaminobacter in the family Phyllobacteriaceae. The 16S rRNA gene of CB3T shared the highest sequence similarities to those of the type strains Pseudaminobacter defluvii THI 051T (97.8 % identity) and Pseudaminobacter salicylatoxidans BN12T (97.4 %). The DNA-DNA relatedness values of CB3T with respect to strains belonging to the genus Pseudaminobacter were less than 70 %. The fatty acid profile of CB3T consisted of C16 : 0, cyclo-C19 : 0ω8c and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) as major components. The major polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylethanolamine and diphosphatidylglycerol. The DNA G+C content was 61.4 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain CB3T was distinct from previously described Pseudaminobacter species. Therefore, we propose that strain CB3T represents a novel species of the genus Pseudaminobacter, Pseudaminobacterarsenicus sp. nov., strain CB3T (=CCTCC AB2016116T=KCTC 52625T) is designated as the type strain.

Removal of toxic metals using ferrate(VI): a review.

Heavy metal contamination of water resources is a critical issue which adversely affects humans. Ferrate(VI) (FeVIO4 2-, Fe(VI)), as a new type of green multifunctional water treatment agent, has shown promising potential for environmental decontamination. A complete understanding of the interactions between ferrate(VI) and toxic metals can be conducive to the further development of ferrate(VI) technology for application to wastewater treatment. This review first introduces the purification of ferrate(VI) technology for toxic metals including free heavy metals and metal complexes briefly. The effective parameters are then analyzed and discussed in detail. Subsequently, the reactivity and mechanisms of ferrate(VI) with toxic metals are emphatically described. Finally, possible research challenges and directions for ferrate(VI) technology applied to wastewater treatment in the future are summarized.

Transmission electron microscopy artifacts in characterization of the nanomaterial-cell interactions.

We investigated transmission electron microscopy artifacts obtained using standard sample preparation protocols applied to the investigation of Escherichia coli cells exposed to common nanomaterials, such as TiO2, Ag, ZnO, and MgO. While the common protocols for some nanomaterials result only in known issues of nanomaterial-independent generation of anomalous deposits due to fixation and staining, for others, there are reactions between the nanomaterial and chemicals used for post-fixation or staining. Only in the case of TiO2 do we observe only the known issues of nanomaterial-independent generation of anomalous deposits due to exceptional chemical stability of this material. For the other three nanomaterials, different artifacts are observed. For each of those, we identify causes of the observed problems and suggest alternative sample preparation protocols to avoid artifacts arising from the sample preparation, which is essential for correct interpretation of the obtained images and drawing correct conclusions on cell-nanomaterial interactions. Finally, we propose modified sample preparation and characterization protocols for comprehensive and conclusive investigations of nanomaterial-cell interactions using electron microscopy and for obtaining clear and unambiguous revelation whether the nanomaterials studied penetrate the cells or accumulate at the cell membranes. In only the case of MgO and ZnO, the unambiguous presence of Zn and Mg could be observed inside the cells.

Functional genes and thermophilic microorganisms responsible for arsenite oxidation from the shallow sediment of an untraversed hot spring outlet.

Hot Springs have unique geochemical features. Microorganisms-mediated arsenite oxidation is one of the major biogeochemical processes occurred in some hot springs. This study aimed to understand the diversities of genes and microorganisms involved in arsenite oxidation from the outlet of an untraversed hot spring located at an altitude of 4226 m. Microcosm assay indicated that the microbial community from the hot spring was able to efficiently oxidize As(III) using glucose, lactic acid, yeast extract or sodium bicarbonate as the sole carbon source. The microbial community contained 7 phyla of microorganisms, of which Proteobacteria and Firmicutes are largely dominant; this composition is unique and differs significantly from those of other described hot springs. Twenty one novel arsenite oxidase genes were identified from the samples, which are affiliated with the arsenite oxidase families of α-Proteobacteria, ß-Proteobacteria or Archaea; this highlights the high diversity of the arsenite-oxidizing microorganisms from the hot spring. A cultivable arsenite-oxidizer Chelatococcu sp. GHS311 was also isolated from the sample using enrichment technique. It can completely convert 75.0 mg/L As(III) into As(V) in 18 days at 45 °C. The arsenite oxidase of GHS311 shares the maximal sequence identity (84.7%) to that of Hydrogenophaga sp. CL3, a non-thermotolerant bacterium. At the temperature lower than 30 °C or higher than 65 °C, the growth of this strain was completely inhibited. These data help us to better understand the diversity and functional features of the thermophilic arsenite-oxidizing microorganisms from hot springs.

Functions and Unique Diversity of Genes and Microorganisms Involved in Arsenite Oxidation from the Tailings of a Realgar Mine.

The tailings of the Shimen realgar mine have unique geochemical features. Arsenite oxidation is one of the major biogeochemical processes that occurs in the tailings. However, little is known about the functional and molecular aspects of the microbial community involved in arsenite oxidation. Here, we fully explored the functional and molecular features of the microbial communities from the tailings of the Shimen realgar mine. We collected six samples of tailings from sites A, B, C, D, E, and F. Microcosm assays indicated that all of the six sites contain both chemoautotrophic and heterotrophic arsenite-oxidizing microorganisms; their activities differed considerably from each other. The microbial arsenite-oxidizing activities show a positive correlation with soluble arsenic concentrations. The microbial communities of the six sites contain 40 phyla of bacteria and 2 phyla of archaea that show extremely high diversity. Soluble arsenic, sulfate, pH, and total organic carbon (TOC) are the key environmental factors that shape the microbial communities. We further identified 114 unique arsenite oxidase genes from the samples; all of them code for new or new-type arsenite oxidases. We also isolated 10 novel arsenite oxidizers from the samples, of which 4 are chemoautotrophic and 6 are heterotrophic. These data highlight the unique diversities of the arsenite-oxidizing microorganisms and their oxidase genes from the tailings of the Shimen realgar mine. To the best of our knowledge, this is the first report describing the functional and molecular features of microbial communities from the tailings of a realgar mine. IMPORTANCE: This study focused on the functional and molecular characterizations of microbial communities from the tailings of the Shimen realgar mine. We fully explored, for the first time, the arsenite-oxidizing activities and the functional gene diversities of microorganisms from the tailings, as well as the correlation of the microbial activities/diversities with environmental factors. The findings of this study help us to better understand the diversities of the arsenite-oxidizing bacteria and the geochemical cycle of arsenic in the tailings of the Shimen realgar mine and gain insights into the microbial mechanisms by which the secondary minerals of the tailings were formed. This work also offers a set of unique arsenite-oxidizing bacteria for basic research of the molecular regulation of arsenite oxidation in bacterial cells and for the environmentally friendly bioremediation of arsenic-contaminated groundwater.

Luteimonas arsenica sp. nov., an arsenic-tolerant bacterium isolated from arsenic-contaminated soil.

A Gram-stain-negative, rod-shaped bacterium that formed yellow and viscous colonies was isolated from arsenic-contaminated soil of the Jianghan plain, Hubei Province, China, and it was designated 26-35T. This strain was capable of resisting arsenate and arsenite with MICs of 40 and 20 mM, respectively. The 16S rRNA gene of the novel isolate displayed 96.7-94.2 % sequence similarities to those of other known species of the genus Luteimonas. The respiratory quinone was ubiquinone-8 (Q-8). The DNA G+C content was 71.4 mol%. The predominant cellular fatty acids were iso-C15 : 0, iso-C16 : 0, iso-C17 : 0, iso-C11 : 0, iso-C11 : 0 3-OH and iso-C17 : 1ω9c. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Phylogenetic and physiological analysis indicated that the isolate represents a novel species of the genus Luteimonas, for which the name Luteimonas arsenica sp. nov. is proposed. The type strain is 26-35T (=KCTC 42824T=CCTCC AB 2014326T).