Gut bacteria, host immunity, and colorectal cancer: From pathogenesis to therapy.

The emergence of 16S rRNA and metagenomic sequencing has gradually revealed the close relationship between dysbiosis and colorectal cancer (CRC). Recent studies have confirmed that intestinal dysbiosis plays various roles in the occurrence, development, and therapeutic response of CRC. Perturbation of host immunity is one of the key mechanisms involved. The intestinal microbiota, or specific bacteria and their metabolites, can modulate the progression of CRC through pathogen recognition receptor signaling or via the recruitment, polarization, and activation of both innate and adaptive immune cells to reshape the protumor/antitumor microenvironment. Therefore, the administration of gut bacteria to enhance immune homeostasis represents a new strategy for the treatment of CRC. In this review, we cover recent studies that illuminate the role of gut bacteria in the progression and treatment of CRC through orchestrating the immune response, which potentially offers insights for subsequent transformative research.

Saikosaponin d protects pancreatic acinar cells against cerulein-induced pyroptosis through alleviating mitochondrial damage and inhibiting cGAS-STING pathway.

Acute pancreatitis represents an inflammatory disease featuring pancreatic necrosis and inflammation. Inflammatory injury of pancreatic acinar cells (PACs) is critically involved in the initiation and progression of acute pancreatitis. Pyroptosis, a new kind of programmed cell death concomitant with a low-grade inflammatory reaction, plays a function in acute pancreatitis pathology. It is unclear whether saikosaponin d (SSd), a pharmacologically active natural product, could protect PACs by regulating pyroptosis. Here, we established a PAC injury model in vitro using cerulein to treat AR42J cells. SSd restored viability and proliferation and lowered the release of pancreatic enzymes and inflammatory interleukins in cerulein-treated AR42J cells. Cerulein-induced pyroptosis was evidenced by typical ultrastructural changes and NLRP3/caspase-1 activation in AR42J cells, but SSd attenuated cerulein-induced pyroptosis and inhibited NLRP3/caspase-1 pathway. Mechanically, SSd reduced mitochondrial damage and mtDNA release, and blocked cGAS-STING signaling in AR42J cells treated with cerulein, contributing to the inhibition of NLRP3-mediated pyroptosis. Furthermore, SSd abolished cerulein-elevated oxidative stress in AR42J cells, leading to the mitigation of mitochondrial damage and inhibition of cGAS-STING signaling and pyroptosis. In conclusion, SSd protected PACs against cerulein-induced pyroptosis by alleviating mitochondrial damage and inhibiting the cGAS-STING pathway, and it could be a therapeutic candidate for acute pancreatitis.

Partial substitution of manure increases N2O emissions in the alkaline soil but not acidic soils.

The fertilization regimes of combining manure with synthetic fertilizer are benefits for crop yields and soil fertility in cropping systems as compared to sole synthetic fertilization, but the responses of nitrous oxide (N2O) emissions to these practices are inconsistent in the literatures. We hypothesized that it is caused by different proportions of nitrogen (N) applied as manure and various soil properties. Here, we conducted a microcosm experiment, and measured the N2O emissions from control (no N) and five manure substitution treatments (supplied 100 mg N kg-1 using the combination of urea with manure) with a range of proportions of N applied as manure (0, 25%, 50%, 75%, and 100%) in three different soil types (fluvo-aquic soil, black soil, and latosol) under aerobic condition. The stimulated effect on N2O emissions was more pronounced after manure application in an alkaline soil with high nitrification rate, due to relatively rapid soil DOC depletion and N mineralization of manure. N2O emissions from partial substitution of urea with manure were significantly higher than manure-only addition under high soil pH due to abundant labile C from manure. However, there was no difference between manure substitution treatments under acid soils. Nitrification inhibitor substantially decreased N2O emissions with increasing soil pH, but it was less effective in mitigating N2O emissions with larger proportion of manure. This is likely due to the slow nitrification under low soil pH, and denitrification derived N2O increased with increasing manure application rate. Collectively, our study shows that the application of manure substitution to alkaline soils requires careful consideration, which might have rapid nitrification potential and hence trigger significant N2O emissions. The knowledge gained in this work will help the decision-makers in optimizing a sound N fertilization regime interacted with soil properties for sustainable crop production and N2O mitigation.

Once-middle amount of straw interlayer enhances saline soil quality and sunflower yield in semi-arid regions of China: Evidence from a four-year experiment.

Straw deep returning as an interlayer is a novel practice to enhance soil carbon and nutrients. However, the impact of applying various amounts of straw as an interlayer on soil quality still remain unclear in the saline soil. Therefore, a field experiment was carried out over four years (2015-2018) in Hetao Irrigation District, China. The aim was to evaluate the impact of four straw interlayer rates (i.e., 0, 6, 12, and 18 Mg ha-1) applied at 40 cm depth on soil quality index (SQI) and its relationship to sunflower yield in saline soil. Our results showed that, in comparison to no straw interlayer (CK), straw interlayers applied at rates of 6, 12, and 18 Mg ha-1 improved SQI on average by 2.0, 2.7, and 3.0 times in four years, respectively (p < 0.05). This suggested that straw deep returning as an interlayer improved SQI, especially for middle and high amounts (12 and 18 Mg ha-1). Partial least squares path model (PLSPM) illustrated that the improvement of SQI was due to the high-moisture and low-salt environment created by straw interlayer in the early two years (2015-2016), while the higher soil nutrients released from straw decomposition in the subsequent years (2017-2018). The improvement of SQI contributed to sunflower yield, which was related to the decrease of soil salinity, the increase of soil moisture, soil organic carbon (SOC), total nitrogen (TN), and available nutrients under straw interlayers. The sunflower yield was increased by 8.7-13.4% under straw interlayers (p < 0.05), following the order of 18 = 12 > 6 >0 Mg ha-1. The greater increment of yield was detected during the initial phase of burying straw interlayers, which indicated that straw as an interlayer played a more important role than nutrient supply from straw decomposition. The findings highlighted that appropriate straw return amount (i.e., 12 Mg ha-1) as an interlayer is an economic practice to benefit soil quality and crop yield synchronously in salt-affected soils.

Lymphoid-specific helicase in epigenetics, DNA repair and cancer.

Lymphoid-specific helicase (LSH) is a member of the SNF2 helicase family of chromatin-remodelling proteins. Dysfunctions or mutations in LSH causes an autosomal recessive disease known as immunodeficiency-centromeric instability-facial anomaly (ICF) syndrome. Interestingly, LSH participates in various aspects of epigenetic regulation, including nucleosome remodelling, DNA methylation, histone modifications and heterochromatin formation. Further, LSH plays a crucial role during DNA-damage repair, specifically during double-strand break (DSB) repair, since murine LSH was shown to be essential for non-homologous end joining (NHEJ) and homologous recombination (HR). Accordingly, overexpression of LSH drives tumorigenesis and malignancy. On the other hand, LSH homologs stabilise the genome. Thus, LSH might be implemented as a biomarker for various cancer types and potential target molecule to develop therapeutic strategies against them. In this review, we focus on the role of LSH in orchestrating chromatin rearrangements, such as DNA methylation and histone modifications, as well as in DNA-damage repair. Changes in chromatin structure may facilitate gene expression signatures that cause malignant transformation. We summarise recent findings of LSH in cancers and raise critical open questions for further studies.

Improvement of multicatalytic properties of nitrilase from Paraburkholderia graminis for efficient biosynthesis of 2-chloronicotinic acid.

Nitrilases are promising biocatalysts to produce high-value-added carboxylic acids through hydrolysis of nitriles. However, since the enzymes always show low activity and sometimes with poor reaction specificity toward 2-chloronicotinonitrile (2-CN), very few robust nitrilases have been reported for efficient production of 2-chloronicotinic acid (2-CA) from 2-CN. Herein, a nitrilase from Paraburkholderia graminis (PgNIT) was engineered to improve its catalytic properties. We identified the beneficial residues via computational analysis and constructed the mutant library. The positive mutants were obtained and the activity of the "best" mutant F164G/I130L/N167Y/A55S/Q260C/T133I/R199Q toward 2-CN was increased from 0.14 × 10-3  to 4.22 U/mg. Its reaction specificity was improved with elimination of hydration activity. Molecular docking and molecular dynamics simulation revealed that the conformational flexibility, the nucleophilic attack distance, as well as the interaction forces between the enzyme and substrate were the main reason alternating the catalytic properties of PgNIT. With the best mutant as biocatalyst, 150 g/L 2-CN was completely converted, resulting in 2-CA accumulated to 169.7 g/L. When the substrate concentration was increased to 200 g/L, 203.1 g/L 2-CA was obtained with yield of 85.7%. The results laid the foundation for industrial production of 2-CA with the nitrilase-catalyzed route.

Sutcliffiella deserti sp. nov., isolated from desert soil.

A Gram-stain-positive, facultative anaerobic, motile and rod-shaped bacterial strain, DG-18T, was isolated from desert soil sampled at the Kubuqi Desert in Inner Mongolia, China. Strain DG-18T grew at 4-40 °C (optimum, 25-30 °C), at pH 8.0-10.0 (optimum, pH 9.0) and with 0-8.0 % (w/v) NaCl (optimum 2.0%). 16S rRNA gene sequence analysis placed strain DG-18T within the genus Sutcliffiella of the family Bacillaceae with Sutcliffiella halmapala DSM 8723T (98.2%), Sutcliffiella zhanjiangensis JSM 099021T (97.6%), Sutcliffiella horikoshii DSM 8719T (97.4%), Sutcliffiella catenulata 18CT (96.6 %) and Sutcliffiella cohnii NBRC 15565T (96.5%) as its closest relatives. The major respiratory quinone of strain DG-18T was MK-7 and the major polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Its major fatty acids were iso-C15 : 0 and iso-C17 : 1 ω10c. The genomic DNA G+C content of strain DG-18T was 38.7 mol% based on total genome calculations. The average nucleotide identity score between the genomic sequence of strain DG-18T and that of S. halmapala DSM 8723T was 76.7 %. The Genome-to-Genome Distance Calculator showed that the DNA-DNA hybridization value for strain DG-18T and S. halmapala DSM 8723T was 21.8%. Based on the polyphasic taxonomic data, strain DG-18T represents a novel species of the genus Sutcliffiella, for which the name Sutcliffiella deserti sp. nov. is proposed. The type strain is DG-18T (=GDMCC 1.17773T=KCTC 43170T).

Description and genome analysis of Luteimonas viscosa sp. nov., a novel bacterium isolated from soil of a sunflower field.

Strain XBU10T was isolated from a soil sample of a sunflower plot in Inner Mongolia, China. The isolate was a Gram-stain-negative, aerobic, non-motile, rod-shaped bacterium, and its colonies were bright yellow in colour. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain XBU10T belonged to the genus Luteimonas of the family Lysobacteraceae and was most closely related to Luteimonas panaciterrae Gsoil 068T (97.8%), Luteimonas marina FR1330T (97.6%), Luteimonas aquatica RIB1-20T (97.4%) and Luteimonas huabeiensis HB2T (97.2%). Growth occurred at 4-40 °C (optimum, 28-30 °C), with 0-5.0% (w/v) NaCl (optimum, 0.5%) and at pH 6.0-10.0 (optimum, pH 7.0 - 8.0). The chemotaxonomic characteristics of strain XBU10T, which had Q-8 as its predominant quinone and iso-C17:1 ω9c, iso-C15:0, iso-C17:0 and iso-C16:0 as its major fatty acids, were consistent with classification in the genus Luteimonas. The polar lipid profile of strain XBU10T comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, two unidentified aminophospholipids and three unidentified polar lipids. The genome of strain XBU10T was 4.17 Mbp with a G + C content of 69.9%. Its genome sequence showed genes encoding alkaline phosphatase and catalase. Protein-coding genes related to carbohydrate-active enzymes were also observed. Average nucleotide identity (ANI) values between XBU10T and other species of the genus Luteimonas were found to be low (ANIm < 88.0%, ANIb < 85.0% and OrthoANIu < 85.0%). Furthermore, digital DNA-DNA hybridization (dDDH) and average amino acid identity (AAI) values between strain XBU10T and the closely related species ranged from 20.3 to 28.9% and from 64.2 to 82.3%, respectively. Based on the results of our phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain XBU10T represents a novel species within the genus Luteimonas, for which the name Luteimonas viscosa sp. nov. is proposed. The type strain is XBU10T (= CGMCC 1.12158T = KCTC 23878T).

In Situ Protease Secretion Visualization and Metastatic Lymph Nodes Imaging via a Cell Membrane-Anchored Upconversion Nanoprobe.

Matrix metalloproteinase (MMP) secretion is highly associated with tumor invasion and metastasis; therefore, monitoring MMP secretion is important for disease progression study and therapy choosing. Though working well for intracellular MMP imaging, the performance of current MMP detection probes is impaired in secretion monitoring due to the diffusion of MMP in an extracellular environment after secretion and low secreted amount. Here, we design a cell membrane-anchored ratiometric upconversion nanoprobe (UCNPs-Cy3/Pep-QSY7/Ab) for in situ MMP secretion visualization. Anti-EGFR is functionalized on the nanoprobe to provide specific recognition to tumor cells and guarantee fast response to MMP2 in the local place of secretion. MMP-responsive cleavage of Pep-QSY7 results in Cy3 luminescence recovery at 580 nm, which is ratioed over an internal standard of UCNP emission at 654 nm for MMP2 detection. The presented cell membrane-anchored ratiometric upconversion nanoprobe demonstrated that satisfactory results for in situ monitoring of MMP2 secretion from MDA-MB-231 cells and MCF-7 cells, as well as in vivo imaging of metastatic lymph nodes, would provide a universal platform for protease secretion study and contribute to tumor invasiveness assessment.

Gains in insurance coverage following the affordable care act and change in preventive services use among non-elderly US immigrants.

Immigrants have lower and disproportionate use of preventive care. We use longitudinal panel data to examine how the 2014 full implementation of the ACA mandates affected change in preventive services (PS) use among immigrants that gained insurance. We used data on Foreign-Born (FB) and US-Born (USB) adults, ages 26-64 years, from the 2013/16 Medical Expenditures Panel Survey longitudinal files to examine within-person change in yearly utilization of age/sex specific United States Preventive Services Task Force (USPSTF) recommended services. We included five primary care (e.g., influenza immunization), three behavioral (e.g., diet), and seven cancer screening (e.g., mammography) measures. We used generalized estimating equations and difference-in-differences tests to assess the effects of insurance gain on: (1) change in PS utilization, and (2) reduction in utilization disparities between USB and FB adults, adjusting for predisposing, health enabling, and health needs factors. Our results showed that newly-insured FB adults substantially increased their use of all primary care checks, and exercise and diet advice. We also found improvements in use of endoscopies, two modalities of colon cancer screening, and prostate cancer screening, but not in receipt of mammography and clinical breast exams. Newly-insured FB PS use remained lower than use among continuously-insured USB adults, but some of the differences were explained by adjustment to enabling and health needs factors. Briefly, health insurance gains among immigrants translated into substantial improvements in use of recommended PS. Still, notable disparities persist among the newly-insured FB, and more so among the 1 in 5 that remain continuously uninsured.

Inhibition of NF-κB is required for oleanolic acid to downregulate PD-L1 by promoting DNA demethylation in gastric cancer cells.

Gastric cancer is one of the most common causes of cancer-related death worldwide. Immunotherapy via programmed cell death protein 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) blockade has shown benefits for gastric cancer. Epigenetic DNA methylation critically regulates cancer immune checkpoints. We investigated how the natural compound oleanolic acid (OA) affected PD-L1 expression in gastric cancer cells. Interleukin-1ß (IL-1ß) at 20 ng/mL was used to stimulate human gastric cancer MKN-45 cells. IL-1ß significantly increased PD-L1 expression, which was abolished by OA. Next, OA-treated MKN-45 cells were co-cultured with activated and PD-1-overexpressing Jurkat T cells. OA restored IL-2 levels in the co-culture system and increased T cell killing toward MKN-45 cells. Overexpression of PD-L1 eliminated OA-enhanced T cell killing capacity; however, PD-1 blocking antibody abrogated the cytotoxicity of T cells. Moreover, OA abolished IL-1ß-increased DNA demethylase activity in MKN-45 cells. DNA methyltransferase inhibitor 5-azacytidine rescued OA-reduced PD-L1 expression; whereas DNA demethylation inhibitor gemcitabine inhibited PD-L1 expression, and, in combination with OA, provided more potent inhibitory effects. Furthermore, OA selectively reduced the expression of DNA demethylase TET3 in IL-1ß-treated MKN-45 cells, and overexpression of TET3 restored OA-reduced PD-L1 expression. Finally, OA disrupted nuclear factor κB (NF-κB) signaling IL-1ß-treated MKN-45 cells, and overexpression of NF-κB restored OA downregulation of TET3 and PD-L1. The cytotoxicity of T cells toward MKN-45 cells was also weakened by NF-κB overexpression. Altogether, OA blocked the IL-1ß/NF-κB/TET3 axis in gastric cancer cells, leading to DNA hypomethylation and downregulation of PD-L1. Our discoveries suggested OA as an epigenetic modulator for immunotherapy or an adjuvant therapy against gastric cancer.

Chitinophaga solisilvae sp. nov., isolated from forest soil.

A Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacterial strain, O9T, was isolated from a forest soil sample collected at Dai, Xishuangbanna, Yunnan Province, PR China. Strain O9T grew optimally at pH 7.0, at 28‒30 °C and in the absence of NaCl. 16S rRNA gene sequence analysis placed strain O9T within the genus Chitinophaga of the family Chitinophagaceae, with Chitinophaga terrae KP01T (97.8 %), Chitinophaga jiangningensis JN53T (97.7 %), Chitinophaga niastensis JS16-4T (97.4 %), Chitinophaga qingshengii JN246T (97.3 %) and Chitinophaga dinghuensis DHOC24T (97.3 %) as its closest relatives. Strain O9T hydrolysed casein, gelatin and Tween 80. It could not assimilate l-arabinose, l-rhamnose, sucrose, melibiose, gentiobiose or d-fructose as a carbon source. It was negative for esterase lipase (C8) and ß-glucosidase. Phosphatidylethanolamine was the predominant polar lipid. The major respiratory quinone of strain O9T was MK-7. Its major fatty acids were iso-C15:0 (34.2 %), C16:1 ω5c (20.9 %) and iso-C17:0 3-OH (12.6 %). The genomic DNA G+C content of strain O9T was 49.0 mol% based on total genome calculations. The average nucleotide identity score between the genomic sequence of strain O9T and that of Chitinophaga terrae KP01T was 72.9%. The Genome-to-Genome Distance Calculator showed that DNA‒DNA hybridization values for strain O9T and Chitinophaga terrae KP01T were 13.6, 21.1 and 14.4%, respectively. Based on the polyphasic taxonomic data, strain O9T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga solisilvae sp. nov. is proposed. The type strain is O9T (=CGMCC 1.12462T=KCTC 32404T).

Identifying disparities in patient-centered care experiences between non-Latino white and black men: results from the 2008-2016 Medical Expenditure Panel Survey.

BACKGROUND: Patient-centered healthcare in the context of a medical home (PCMH) is an important pathway to reducing healthcare inequities. To date, no work has examined the prevalence of care experiences associated with PCMH among non-elderly Black males. METHODS: We analyzed data, on 22 indicators representative of six healthcare domains associated with PCMH experiences, from non-Latino White (NLW) and Black males aged 18-64 from the 2008-2016 Medical Expenditure Panel Survey (n = 47,405). We used generalized linear models to test whether Behavioral Model factors attenuate any differences in access to these domains between NLW and Black males, and decomposition techniques to examine the contribution of these factors to reported differences. RESULTS: Black males reported 1) lower access to personal primary care providers, 2) poorer quality communication with providers, and 3) lower levels of care comprehensiveness (all p < 0.05). Differences between groups were attenuated but not eliminated by accounting for the Behavioral Model factors particularly through enabling and predisposing factors. Group health characteristics were not a primary driver of racial differences in care experiences across all the considered domains. CONCLUSIONS: Black men, in the U.S, continue to face barriers to accessing high quality, patient-centered care, specifically as it relates to accessing specialty care, medical tests, and patient-provider communication.

Paenibacillus luteus sp. nov., isolated from soil.

A novel Gram-stain-positive, strictly aerobic, motile, spore-forming and rod-shaped bacterial strain, designated R-3T, was isolated from a soil sample obtained from the shore of Lake Panyang, Sichuan Province, PR China. Strain R-3T hydrolysed starch and casein. It could not assimilate d-glucose as a carbon source, or produce acid from d-glucose and l-arabinose. Phylogenetic, phenotypic, chemotaxonomic and molecular studies were performed on the new isolate. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain R-3T was a member of the genus Paenibacillus, exhibiting the highest sequence similarity to Paenibacillus sinopodophylli TEGR-3T (98.4 %). The organism grew at 4-38 °C (optimum, 28-30 °C), at pH 6.0-10.0 (pH 7.0-7.5) and with 0-2.5 % (w/v) NaCl (1 %). The predominant menaquinone was MK-7. Anteiso-C15 : 0 (60.7 %) and C16 : 0 (15.5 %) were the major fatty acids. The cellular polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, three unidentified aminophospholipids and one unidentified phospholipid. The DNA G+C content of strain R-3T was determined to be 47.0 mol%. The DNA-DNA relatedness between strain R-3T and P. sinopodophylli TEGR-3T was 21.2 %. Based on the results obtained in this study, strain R-3T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillusluteus sp. nov. is proposed. The type strain is R-3T (=CGMCC 1.16135T=KCTC 33912T).

Design, synthesis and biological activity of deuterium-based FFA1 agonists with improved pharmacokinetic profiles.

The free fatty acid receptor 1 (FFA1) is considered as a promising anti-diabetic target based on its function of glucose-stimulated insulin secretion. The previously reported compound 2 is a highly potent FFA1 agonist, but it might be suffered from poor pharmacokinetic properties because the phenylpropanoic acid is vulnerable to ß-oxidation. To identify orally available analogs, we tried to block the route of ß-oxidation by incorporating deuterium at phenylpropionic acid moiety. As expected, the deuterium-based analogs 3 and 4 exhibited better pharmacokinetic properties than parent compound 2. Although the difference of potency between compound 2 and 3 is quite small, the glucose-lowering effect of deuterium analog 3 was better than that of compound 2. Meanwhile, compound 3 docked well into the same binding pocket of TAK-875, and formed almost identical interactions of TAK-875 in binding site. Different from glibenclamide, a lower risk of hypoglycemia was observed in compound 3 even at the high dose of 60 mg/kg.

Boosting Luminance Energy Transfer Efficiency in Upconversion Nanoparticles with an Energy-Concentrating Zone.

Despite the successful application of upconversion nanoparticles (UCNPs), their low energy transfer efficiency is still a bottleneck to further applications. Here we design UCNPs with a multilayer structure, including an inert NaYF4 :Gd core and an energy-concentrating zone (ECZ), for efficient energy concentration. The ECZ is composed of an emitting layer of NaYF4 :Yb,Er and an absorption layer of NaYF4 :Nd,Yb with antenna IRDye 800CW to manipulate the energy transfer. The stable and tight packing of 800CW linked originally with a bisphosphonate ligand improves greatly the transfer efficiency. The proximity of the emitting layer to both surface antenna and accepter also decreases energy depletion. Compared to classical UCNPs, the ECZ UCNPs show 3600 times higher luminescence intensity with an energy transfer efficiency near 60 %. In proof-of-concept applications, this type of structure was employed for Hg2+ detection and for photodynamic therapy under hypoxic conditions.

Rhizobium helianthi sp. nov., isolated from the rhizosphere of sunflower.

A Gram-stain-negative, non-spore-forming, rod-shaped and aerobic bacterium, designated Xi19T, was isolated from a soil sample collected from the rhizosphere of sunflower (Helianthus annuus) in Wuyuan county of Inner Mongolia, China and was characterized taxonomically by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolate was related to species of the genus Rhizobium, sharing the greatest 16S rRNA gene sequence similarity with Rhizobium rhizoryzae J3-AN59T (98.4 %), followed by Rhizobium pseudoryzae J3-A127T (97.4 %). There were low similarities ( < 91 %) between the atpD, recA and glnII gene sequences of the novel strain and those of members of the genus Rhizobium. DNA-DNA hybridization values between strain Xi19T and the most related strain Rhizobium rhizoryzae J3-AN59T were low. The major cellular fatty acids of strain Xi19T were C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C19 : 0 cyclo ω8c. Q-10 was identified as the predominant ubiquinone and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The DNA G+C content of strain Xi19T was 60.2 mol%. On the basis of physiological and biochemical characteristics, coupled with genotypic data obtained in this work, strain Xi19T represents a novel species of the genus Rhizobium, for which the name Rhizobium helianthi is proposed. The type strain is Xi19T ( = CGMCC 1.12192T = KCTC 23879T).

[Chemical Constituents from Dalbergia cochinchinensis].

OBJECTIVE: To investigate the chemical constituents from the heartwood of Dalbergia cochinchinensis. METHODS: Isolate and purify compounds by various column chromatographic methods. Spectral analysis were taken to identify the structures. RESULTS: Elev- en compounds were isolated and identified as dibutyl terephthalate (1), medicarpin (2), pterostilbene (3), 6-hydroxy-2-(2-hydroxy-4- methoxyphenyl)-benzofuran (4), pterocarpol (5), butyl isobutyl phthalate (6), pterolinus B (7), methyl 4-hydroxybenzoate (8), ethyl 4- hydroxybenzoate (9),2-(2'-methoxy-4'-hydroxy)-aryl-3-methyl-6-hydroxy-benzofuran (10) and 6α-hydroxycyclonerolidol (11). CONCLUSION: Compounds 1 and 6~10 are isolated from Dalbergia genus for the first time, and compounds 2, 4 and 11 are isolated from this plant for the first time.

Spectroscopic properties and continuous-wave laser operation of Yb:LuPO4 crystal.

For the first time, and to the best of our knowledge, we report a continuous-wave (cw) laser operation of Yb:LuPO4 crystal, demonstrated at room temperature in a compact plano-concave resonator end pumped by a diode laser. 1.61 W of cw output power around 1039 nm were generated with 2.40 W of pump power at 976 nm absorbed in a 0.3 mm thick crystal, leading to an optical-to-optical efficiency of 67%, whereas the slope efficiency was 75%. Polarized absorption and emission cross-section spectra are also presented and discussed in detail.

Pseudoxanthomonas wuyuanensis sp. nov., isolated from saline-alkali soil.

A bacterium, designated XC21-2(T), was isolated from a saline-alkaline soil sample from China. Cells were Gram-stain-negative, rod-shaped and motile and grew optimally at 35-37 °C, pH 6.0-7.0 and in the presence of 0.5% (w/v) NaCl. Growth occurred in the range pH 5.5-9.0 and in the presence of up to 4 % (w/v) NaCl. The major cellular fatty acids were iso-C15 : 0, iso-C16 : 0 and iso-C17 : 1ω9c. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an uncharacterized amino-group-containing polar lipid. The major quinone was ubiquinone 8 (Q-8) and the G+C content of the genomic DNA was 66.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain XC21-2(T) formed a tight phylogenetic lineage with Pseudoxanthomonas dokdonensis KCTC 12543(T) within the genus Pseudoxanthomonas and was most closely related to P. dokdonensis KCTC 12543(T) and P. mexicana ATCC 700993(T), with 97.9 and 97.5 % 16S rRNA gene sequence similarity, respectively. On the basis of the unique physiological profile of the isolate and its phylogenetic divergence from known species, strain XC21-2(T) represents a novel species within the genus Pseudoxanthomonas, for which the name Pseudoxanthomonas wuyuanensis sp. nov. is proposed. The type strain is XC21-2(T) ( = CGMCC 1.10978(T) = KCTC 23877(T)).