Fabrication of Inorganic Coatings Incorporated with Functionalized Graphene Oxide Nanosheets for Improving Fire Retardancy of Wooden Substrates.

Flame-retardant chemicals are frequently used within consumer products and can even be employed as a treatment on the surface of different types of materials (e.g., wood, steel, and textiles) to prevent fire or limit the rapid spread of flames. Functionalized graphene oxide (FGO) nanosheets are a promising construction coating nanomaterial that can be blended with sodium metasilicate and gypsum to reduce the flammability of construction buildings. In this work, we designed and fabricated novel and halogen-free FGO sheets using the modified Hummers method; and subsequently functionalized them by pentaerythritol through a chemical impregnation process before dispersing them within the construction coating. Scanning electron microscopic images confirm that the FGO-filled coating was uniformly dispersed on the surface of wooden substrates. We identified that the FGO content is a critical factor affecting the fire retardancy. Thermogravimetric analysis of the FGO coating revealed that higher char residue can be obtained at 700 °C. Based on the differential scanning calorimetry, the exothermic peak contained a temperature delay in the presence of FGO sheets, primarily due to the formation of a thermal barrier. Such a significant improvement in the flame retardancy confirms that the FGO nanosheets are superior nanomaterials to be employed as a flame-retardant construction coating nanomaterial for improving thermal management within buildings.

Control of pathogenic fungi on Panax notoginseng by volatile oils from the food ingredients Allium sativum and Foeniculum vulgare.

To screen natural drugs with strong inhibitory effects against pathogenic fungi related to P. notoginseng, the antifungal activities of garlic and fennel EOs were studied by targeting P. notoginseng disease-associated fungi, and the possible action mechanisms of garlic and fennel EOs as plant fungicides were preliminarily discussed. At present, the antifungal mechanism of EOs has not been fully established. Therefore, understanding the antifungal mechanism of plant EOs is helpful to address P. notoginseng diseases continuous cropping disease-related obstacles and other agricultural cultivation problems. First, the Oxford cup method and chessboard were used to confirm that the EOs and oxamyl had a significant inhibitory effect on the growth of Fusarium oxysporum. F. oxysporum is the main pathogen causing root rot of P. notoginseng and the preliminary study on the antifungal mechanisms of the EOs against F. oxysporum showed that the inhibition of EOs mainly affects cell membrane permeability and cell processes and affects the enzyme activities of micro-organism, to achieve antifungal effects. Finally, an in vivo model verified that both two EOs could significantly inhibit the occurrence of root rot caused by F. oxysporum.

Chemical Constituents of the Essential oil from Cuminum cyminum L. and Its Antifungal Activity against Panax notoginseng Pathogens.

Cuminum cyminum L. (Cumin) is a flavoring agent that is commonly used worldwide, and is rich in essential oil. Essential oils (Eos) have been intensively investigated in regard to their potential for disease control in plants, which is provided a chance for the blossom of green pesticides. The chemical components of Cumin essential oil (CEO) were revealed by GC/MS, such as cuminaldehyde (44.53 %), p-cymene (12.14 %), (-)-ß-pinene (10.47 %) and γ-terpinene (8.40 %), and found they can inhibit the growth of P. notoginseng-associated pathogenic fungi in vitro and the inhibitory effect of cuminaldehyde was similar to that of hymexazol. SEM and TEM images demonstrated that cuminaldehyde and CEO increased cell permeability and disrupted membrane integrity. The expression of disease-related genes of Fusarium oxysporum showed that CEO induced the expression of most genes, which disrupted biosynthesis, metabolism and signaling pathways. These studies verified the potential of CEO as a plant fungicide that is environmentally friendly and provided ideas for developing new products for controlling root diseases that affect P. notoginseng.

Geographical traceability and multielement analysis of edible and medicinal fungi: Taking Wolfiporia cocos (F.A. Wolf) Ryvarden and Gilb. as an example.

Different geographical environment has a certain influence on the accumulation of fungi elements and chemical components. However, our knowledge is limited to elucidate the fungi elements in response to heterogeneous environmental and the quality differences among different habitats. Here, multielement analysis, FTIR spectrum, and feature-level fusion technique combined with chemometrics were used to study Wolfiporia cocos from different geographical areas, different sampling sites and different altitude sources. From the results, (1) there is significant difference in element content of samples from different sampling sites and no positive correlation with geographical ranges. (2) There is a correlation between elevation and elements, and relatively low elevation (<1,800 m) is conducive to the enrichment of elements. (3) From the perspective of elements, the W. cocos in Yuxi have relatively better quality. (4) FTIR and feature-level models can well realize origin identification. The SVM models are better than the PLS-DA models, and the feature-level model is better than the single FTIR models. In summary, this study demonstrated that the developed method was reliable and could realize the genuineness evaluation and origin identification of W. cocos. The results have implications for the establishment of the technology system of geographical traceability and the development of high-quality geographical indication products of W. cocos.

Application of Identification and Evaluation Techniques for Ethnobotanical Medicinal Plant of Genus Panax: A Review.

Genus Panax, as worldwide medicinal plants, has a medical history for thousands of years. Most of the entire genus are traditional ethnobotanical medicine in China, Myanmar, Thailand, Vietnam and Laos, which have given rise to international attention and use. This paper reviewed more than 210 articles and related books on the research of Panax medicinal plants and their Chinese patent medicines published in the last 30 years. The purpose was to review and summarize the species classification, geographical distribution, and ethnic minorities medicinal records of the genus Panax, and further to review the analytical tools and data analysis methods for the authentication and quality assessment of Panax medicinal materials and Chinese patent medicines. Five main technologies applied in the identification and evaluation of Panax have been introduced and summarized. Chromatography was the most widely used one. Further research and development of molecular identification technology had the potential to become a mainstream identification technology. In addition, some novel, controversial, and worthy methods including electronic noses, electronic eyes, and DNA barcoding were also introduced. At the same time, more than 80% of the researches were carried out by a combination of chemometric pattern-recognition technologies and multi-analysis technologies. All the technologies and methods applied can provide strong support and guarantee for the identification and evaluation of genus Panax, and also conduce to excellent reference value for the development and in-depth research of new technologies in Panax.

Comparison and quantitative analysis of wild and cultivated Macrohyporia cocos using attenuated total refection-Fourier transform infrared spectroscopy combined with ultra-fast liquid chromatography.

Dried sclerotium of Macrohyporia cocos is a well-known and widely-consumed traditional Chinese medicine and is also used as dietary supplement. According to the differential treatment between cultivation and wild habitats in the market, the comparison and quantitative analysis of wild and cultivated M. cocos were performed using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy and ultra-fast liquid chromatography combined with partial least squares discriminant analysis and partial least squares regression (PLSR). 636 samples were used for the spectral scan and chromatographic analysis. Results indicated that contents of dehydrotumulosic acid, poricoic acid A and dehydrotrametenolic acid in cultivated samples were significantly different from wild samples in two medicinal parts. Differences of dehydropachymic acid and pachymic acid just existed in inner part samples (P < 0.05). Wild M. cocos samples could be discriminated with cultivated samples with >95.14% efficiency using spectral data. ATR-FTIR combined with PLSR provided satisfactory performance for content predictions of poricoic acid A and dehydrotrametenolic acid. This study demonstrated that growth patterns could affect the quality of inner part and epidermis of M. cocos, and ATR-FTIR was a promising technique for the identification of wild and cultivated M. cocos and the rapid determination of triterpene acids contents.

Original plant traceability of Dendrobium species using multi-spectroscopy fusion and mathematical models.

Dendrobium is the largest genus of orchids most of which have excellent medicinal properties. Fresh stems of some species have been consumed in daily life by Asians for thousands of years. However, there are differences in flavour and clinical efficacy among different species. Therefore, it is necessary for a detector to establish an effective and rapid method controlling botanical origins of these crude materials. In our study, three spectroscopies including mid-infrared (MIR) (transmission and reflection mode) and near-infrared (NIR) spectra were investigated for authentication of 12 Dendrobium species. Generally, two fusion strategies, reflection MIR and NIR spectra, were combined with three mathematical models (random forest, support vector machine with grid search (SVM-GS) and partial least-squares discrimination analysis (PLS-DA)) for discrimination analysis. In conclusion, a low-level fusion strategy comprising two spectra after pretreated by the second derivative and multiplicative scatter correction was recommended for discrimination analysis because of its excellent performance in three models. Compared with MIR spectra, NIR spectra were more responsible for the discrimination according to a bi-plot analysis of PLS-DA. Moreover, SVM-GS and PLS-DA were suitable for accurate discrimination (100% accuracy rates) of calibration and validation sets. The protocol combined with low-level fusion strategy and chemometrics provides a rapid and effective reference for control of botanical origins in crude Dendrobium materials.

Geographical Authentication of Macrohyporia cocos by a Data Fusion Method Combining Ultra-Fast Liquid Chromatography and Fourier Transform Infrared Spectroscopy.

Macrohyporia cocos is a medicinal and edible fungi, which is consumed widely. The epidermis and inner part of its sclerotium are used separately. M. cocos quality is influenced by geographical origins, so an effective and accurate geographical authentication method is required. Liquid chromatograms at 242 nm and 210 nm (LC242 and LC210) and Fourier transform infrared (FTIR) spectra of two parts were applied to authenticate the geographical origin of cultivated M. cocos combined with low and mid-level data fusion strategies, and partial least squares discriminant analysis. Data pretreatment involved correlation optimized warping and second derivative. The results showed that the potential of the chromatographic fingerprint was greater than that of five triterpene acids contents. LC242-FTIR low-level fusion took full advantage of information synergy and showed good performance. Further, the predictive ability of the FTIR low-level fusion model of two parts was satisfactory. The performance of the low-level fusion strategy preceded those of the single technique and mid-level fusion strategy. The inner parts were more suitable for origin identification than the epidermis. This study proved the feasibility of the data fusion of chromatograms and spectra, and the data fusion of different parts for the accurate authentication of geographical origin. This method is meaningful for the quality control of food and the protection of geographical indication products.

Comprehensive quality assessment of Dendrubium officinale using ATR-FTIR spectroscopy combined with random forest and support vector machine regression.

Dendrobium officinale, as a tonic herb, has attracted more and more consumers to consume in daily life. In order to protect the wild resource, the herb has made great progress though cultivation in vitro. However, the quality is fluctuated in Chinese herbal medicine market due to influence such as cultivated areas and harvesting period. Therefore, the herbal samples from different cultivated locations were evaluated with high-performance liquid chromatography with diode array detector (HPLC-DAD) in terms of two chemical components, quercetin and erianin. In addition, two markers in leaf and stem also were used for support vector machine regression (SVMR) prediction. Samples from different harvesting periods were also classified using attenuated total reflectance mid-infrared spectroscopy coupled with random forest model. The results indicated that Pu'er and Menghai in Yunnan Province were suitable places for the herb cultivation and the leaf of the herb was also an exploitable resource just in light of the content of two components. What's more, combination of suitable spectra pretreatment and grid search method efficiently improved the prediction performance of the regression model. The results of random forest model indicated that important variables combination between stem and leaf was an effective tool to predict the harvesting time of the herb with 94.44% accuracy in calibration set and 97.92% classification correct rate in validation set. The results of combination were better than the models using individual stem and leaf spectra. In addition, the suitable harvesting time (December) could be classified efficiently. Our study provides a reference for quality control of raw materials from D. officinale herb.

Quantification and Discrimination of in Vitro Regeneration Swertia nervosa at Different Growth Periods using the UPLC/UV Coupled with Chemometric Method.

BACKGROUND: Swertia nervosa (Wall. ex G. Don) C. B. Clarke, a promising traditional herbal medicine for the treatment of liver disorders, is endangered due to its extensive collection and unsustainable harvesting practices. OBJECTIVE: The aim of this study is to discuss the diversity of metabolites (loganic acid, sweroside, swertiamarin, and gentiopicroside) at different growth stages and organs of Swertia nervosa using the ultra-high-performance LC (UPLC)/UV coupled with chemometric method. METHODS: UPLC data, UV data, and data fusion were treated separately to find more useful information by partial least-squares discriminant analysis (PLS-DA). Hierarchical cluster analysis (HCA), an unsupervised method, was then employed for validating the results from PLS-DA. RESULTS: Three strategies displayed different chemical information associated with the sample discrimination. UV information mainly contributed to the classification of different organs; UPLC information was prominently responsible for both organs and growth periods; the data fusion did not perform with apparent superiority compared with single data analysis, although it provided useful information to differentiate leaves that could not be recognized by UPLC. The quantification result showed that the content of swertiamarin was the highest compared with the other three metabolites, especially in leaves at the rooted stage (19.57 ± 5.34 mg/g). Therefore, we speculated that interactive transformations occurred among these four metabolites, facilitated by root formation. CONCLUSIONS: This work will contribute to exploitation of bioactive compounds of S. nervosa, as well as its large-scale propagation. HIGHLIGHTS: The roots formation may influence the distribution and accumulation of metabolites.

[Data fusion and multi-components quantitative analysis for identification and quality evaluation of Gentiana rigescens from different geographical origins].

The accumulation of secondary metabolites of traditional Chinese medicine (TCM) is closely related to its origins. The identification of origins and multi-components quantitative evaluation are of great significance to ensure the quality of medicinal materials. In this study, the identification of Gentiana rigescens from different geographical origins was conducted by data fusion of Fourier transform infrared (FTIR) spectroscopy and high performance liquid chromatography (HPLC) in combination of partial least squares discriminant analysis; meanwhile quantitative analysis of index components was conducted to provide an accurate and comprehensive identification and quality evaluation strategy for selecting the best production areas of G. rigescens. In this study, the FTIR and HPLC information of 169 G. rigescens samples from Yunnan, Sichuan, Guangxi and Guizhou Provinces were collected. The raw infrared spectra were pre-treated by multiplicative scatter correction, standard normal variate (SNV) and Savitzky-Golay (SG) derivative. Then the performances of FTIR, HPLC, and low-level data fusion and mid-level data fusion for identification were compared, and the contents of gentiopicroside, swertiamarin, loganic acid and sweroside were determined by HPLC. The results showed that the FTIR spectra of G. rigescens from different geographical origins were different, and the best pre-treatment method was SNV+SG-derivative (second derivative, 15 as the window parameter, and 2 as the polynomial order). The results showed that the accuracy rate of low- and mid-level data fusion (96.43%) in prediction set was higher than that of FTIR and HPLC (94.64%) in prediction set. In addition, the accuracy of low-level data fusion (100%) in the training set was higher than that of mid-level data fusion (99.12%) in training set. The contents of the iridoid glycosides in Yunnan were the highest among different provinces. The average content of gentiopicroside, as a bioactive marker in Chinese pharmacopoeia, was 47.40 mg·g⁻¹, and the maximum was 79.83 mg·g⁻¹. The contents of loganic acid, sweroside and gentiopicroside in Yunnan were significantly different from other provinces (P<0.05). In comparison of total content of iridoid glycosides in G. rigescens with different geographical origins in Yunnan, it was found that the amount of iridoid glycosides was higher in Eryuan Dali (68.59 mg·g⁻¹) and Yulong Lijiang (66.68 mg·g⁻¹), significantly higher than that in Wuding Chuxiong (52.99 mg·g⁻¹), Chengjiang Yuxi (52.29 mg·g⁻¹) and Xundian Kunming (46.71 mg·g⁻¹) (P<0.05), so these two places can be used as a reference region for screening cultivation and excellent germplasm resources of G. rigescens. A comprehensive and accurate method was established by data fusion of HPLC-FTIR and quantitative analysis of HPLC for identification and quality evaluation of G. rigescens, which could provide a support for the development and utilization of G. rigescens.

Phytochemistry and Pharmacological Activities of the Genus Swertia (Gentianaceae): A Review.

Swertia plants have been considered to be medicinal plants useful for the treatment of various ailments for thousands of years, especially in Asian countries. This is due to the broad variety of chemical compounds that provide multiple ligands for bonding to different endogenous biomacromolecules for patients. Chemical constituents and pharmacological activities of Swertia plants are summarized in this paper. Approximately 419 metabolites and 40 bioactive compounds have been reported from 30 Swertia species, including xanthones, flavonoids, seco-iridiods, iridiods, triterpenoids, alkaloids, volatiles, and other secondary metabolites. The bioactivities of Swertia plants include anticarcinogenic, hepatoprotective, anti-oxidant, hypoglycemic, anthelmintic, antibacterial, antifungal, anti-diabetic, gut, and airways modulatory, metabolizing isozymes inhibitory, neuroprotective, HIV-I reverse transcriptases inhibitory, anticholinergic, and CNS-depressant activities, etc. In addition, biosynthetic pathways of xanthones, and seco-iridiods, two most important secondary metabolites for Swertia, are elucidated. The xanthones biosynthetic pathway is a mixed biosynthetic pathway involved the shikimate and the malonate routes, and the seco-iridoid pathway starts with geraniol derived from IPP which is produced either via the MEP or the MVA pathway. This review will offer a reference for future researches on the protection of natural resources, the investigation of therapeutic basis, new drug development, and so forth. Metabolic pathways of some crucial active compounds were also discussed in this review.

Using UHPLC and UV-vis Fingerprint Method to Evaluate Substitutes for Swertia mileensis: An Endangered Medicinal Plant.

BACKGROUND: Millions of people are killed by viral hepatitis every year in the world, whereas many relevant medicines are too expensive to purchase. Swertia mileensis, a medicinal plant for hepatitis in the system of traditional Chinese medicine, has been vanishing gradually because of overexploitation. OBJECTIVE: To find substitutes of S. mileensis and reduce the cost of purchasing drugs for hepatitis patients, the similarity of phytochemical constituents between S. mileensis and other three Swertia species was compared. MATERIALS AND METHODS: Both ultra high performance liquid chromatographies and ultraviolet-vis fingerprints of four Swertia species were developed. Methanol extracts of the stems and leaves were used as samples to establish the fingerprint. The calibration curve was drawn for quantitative analysis of swertiamarin. The data of ultra high performance liquid chromatographies were evaluated statistically using similarity analysis and principal component analysis. RESULTS: The result shows a significant difference at area of 204-290 nm in the ultraviolet fingerprint. Swertiamarin, the only one common peak, was defined in chromatographic fingerprints of four Swertia species. The quantitative analysis suggested that the highest concentration of swertiamarin is in S. davidii. The similarity indexes between different samples were almost under 0.60. In the principal component analysis, separate points not only represent the distinction among different species, but also perform chemical discrepancies in content between stems and leaves of one same species. CONCLUSIONS: S. angustifolia, S. davidii, and S. punicea are not suitable as substitutes of S. mileensis because of their remarkable differences in entirety and local part. In order to address issues about substitutes and high cost of purchasing drugs, more studies need to undertake. SUMMARY: The UHPLC fingerprint method indicated the significant difference on chemical ingredients in four plants from Swertia.Swertiamarin is the unique common compounds for four plants, which exist are in leaves of S. davidii with the highest content.The obvious diversity in four plants was displayed from comprehensive point of view though similarity assay and PCA analysis.The UV fingerprint method offsets the defect that the UHPLC fingerprint reflected messages of secoiridoid glycosides only. Abbreviation used: UHPLC: Ultra high performance liquid chromatography, UV-vis: Ultraviolet-vis, HBV: Anti-hepatitis virus, DNA: Deoxyribonucleic acid, PCA: Principal component analysis, D-GaIN: D-Galactosamine, BCG: Bacille Calmette-Guerin, LPS: Lipopolysaccharide.

Comprehensive Quality Assessment Based Specific Chemical Profiles for Geographic and Tissue Variation in Gentiana rigescens Using HPLC and FTIR Method Combined with Principal Component Analysis.

Roots, stems, leaves, and flowers of Longdan (Gentiana rigescens Franch. ex Hemsl) were collected from six geographic origins of Yunnan Province (n = 240) to implement the quality assessment based on contents of gentiopicroside, loganic acid, sweroside and swertiamarin and chemical profile using HPLC-DAD and FTIR method combined with principal component analysis (PCA). The content of gentiopicroside (major iridoid glycoside) was the highest in G. rigescens, regardless of tissue and geographic origin. The level of swertiamarin was the lowest, even unable to be detected in samples from Kunming and Qujing. Significant correlations (p < 0.05) between gentiopicroside, loganic acid, sweroside, and swertiamarin were found at inter- or intra-tissues, which were highly depended on geographic origins, indicating the influence of environmental conditions on the conversion and transport of secondary metabolites in G. rigescens. Furthermore, samples were reasonably classified as three clusters along large producing areas where have similar climate conditions, characterized by carbohydrates, phenols, benzoates, terpenoids, aliphatic alcohols, aromatic hydrocarbons, and so forth. The present work provided global information on the chemical profile and contents of major iridoid glycosides in G. rigescens originated from six different origins, which is helpful for controlling quality of herbal medicines systematically.

[Studies on sexual organs and embryological development morphology of Pterocypsela formosana].

In this study, the embryological characters of Pterocypsela formosana (Asteraceae) were investigated with the traditional paraffin section methods. The anther has 4 sporangiates, the anther wall development follows the dicotyledonous type and comprises of an epidermis, endothelium, a middle layer and a single-layered tapetum, the tapetum belongs to glandular type. Meiosis of the microspore mother cells is of the simultaneous type, for the formation of mostly tetrahedral tetrad, the mature pollen grains are 2 celled. The ovary is bicarpellate, unilocular, one ovule and basal placenta, the ovule is unitegmic, tenuinucellate, inverted campylotropous and with developed endothelium, archesporial cell of megaspore differentiates immediately below the nucellar epidermis and functions as megasporocyte after development and belongs to tenuinucellate ovule type. The megasporocyte undergoes meitotic to form a liner tetrad, only one chalazal megaspore becomes the functional megaspore which forms female gametophyte including 7-celled and 8-nucleated after three successive mitosis, the female gametophyte is of the Polygonum type. Two polar nuclei melt into a secondary nuclei before fertilization, the chalazal antipodal cells are ephemeral and degenerate shortly after forming. Fertilization is porogamous and belongs to premitotic type of syngamy. The division of the primary endosperm nucleus is earlier than the zygote, the endosperm is of the nuclear type with the presence of haustoria, and the embryogeny belongs to asterad type chicory variant. The developed suspensor on early stage has important significance to the embryo development.

Investigation of metabolites accumulation in medical plant Gentiana rigescens during different growing stage using LC-MS/MS and FT-IR.

BACKGROUND: Gentiana rigescens, an important medicinal plant in China, has been widely cultivated in Yunnan province, China. Previous studies were focused on analysis and determination of the metabolites isolated from this species, the accumulation of these metabolites during growth period are not yet clear. In this study, samples for the experiments were obtained by tissue culture. FT-IR and LC-MS/MS method were performed to distinguish the variation on the major metabolites in G. rigescens during growing stage when combined with chemometrics. RESULTS: Methodology validations were all within the required limits. The metabolites were visually different in tissue culture samples and mature plants. The diversity of metabolites increased proportionally with plant growth. The quantitative analysis showed the content of gentiopicroside was significantly vary during different growing stage. The highest content of gentiopicroside (122.93 ± 7.01 mg/g) was detected in leaf of regenerated plantlet, whereas its content in root significantly increased along with underground parts growth. Moreover, flavonoids mainly distributed in aerial parts showed potential competitive relationship during plant growth. CONCLUSION: The distribution and accumulation of metabolites are associated with different parts and plant growth, which provide potential evidences for the rational application and exploitation of G. rigescens.

Halomonas zhanjiangensis sp. nov., a halophilic bacterium isolated from a sea urchin.

A novel Gram-negative, slightly halophilic, catalase-positive, oxidase-negative, obligately aerobic, non-sporulating rod-shaped bacterium, designated strain JSM 078169(T), was isolated from a sea urchin (Hemicentrotus pulcherrimus) collected from the South China Sea. Growth occurred with 1-20 % (w/v) total salts (optimum, 3-5 %), at pH 6.0-10.5 (optimum, pH 7.5) and at 4-40 degrees C (optimum, 25-30 degrees C). The major cellular fatty acids were C(18 : 1)omega7c, C(16 : 0) and C(12 : 0) 3-OH. The predominant respiratory quinone was Q-9 and the genomic DNA G+C content was 55.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain JSM 078169(T) should be assigned to the genus Halomonas. The sequence similarities between the isolate and the type strains of members of the genus Halomonas were in the range 92.4-97.0 %. The combination of phylogenetic analysis, DNA-DNA relatedness, phenotypic characteristics and chemotaxonomic data supported the view that strain JSM 078169(T) represents a novel species of the genus Halomonas, for which the name Halomonas zhanjiangensis sp. nov. is proposed, with JSM 078169(T) (=CCTCC AB 208031(T)=DSM 21076(T)=KCTC 22279(T)) as the type strain.

Halomonas sediminis sp. nov., a new halophilic bacterium isolated from salt-lake sediment in China.

A novel Gram-negative, slightly halophilic, catalase- and oxidase-positive, obligately aerobic bacterium, strain YIM-C248(T), was isolated from a sediment sample collected from a salt-lake in the Qaidam Basin in Qinghai, north-west China. Cells were non-sporulating short rods, occurring singly or as doublets, motile with peritrichous flagella. Growth occurred with 1-15% (w/v) NaCl [optimum 2-4% (w/v) NaCl], at pH 6.0-10.0 (optimum pH 7.5) and at 4-35 degrees C (optimum 25-30 degrees C). The major cellular fatty acids were C(18:1) omega 7c, C(12:0) 3-OH, cyclo C(19:0) omega 8c, C(16:0) and C(16:1). The predominant respiratory quinone was Q-9 and the genomic DNA G + C content was 58.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YIM-C248(T) should be assigned to the genus Halomonas. The sequence similarities between the isolate and the type strains of members of the genus Halomonas were in the range of 92.5-97.5%. The combination of phylogenetic analysis, DNA-DNA hybridization data, phenotypic characteristics and chemotaxonomic differences supported the view that strain YIM-C248(T) represents a new species of the genus Halomonas, for which the name Halomonas sediminis sp. nov. is proposed, with YIM-C248(T) (=CCTCC AA 207031 = KCTC 22167) as the type strain.