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1.
Pharm Biol ; 62(1): 621-633, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-39056547

RESUMEN

CONTEXT: Pyrus calleryana Decne (Rosaceae), renowned for its therapeutic properties, is known to moisturize the lungs (removing dryness; relieving cough), clear heat (acting as an antipyretic; febrifuge) and aid in detoxification (relieving pyogenic inflammation; eliminating toxins). However, scientific evidence supporting its efficacy in wound healing is lacking. OBJECTIVE: This study investigated P. calleryana samples collected over a year to explore metabolite variations and their impact on skin wound-healing activities. MATERIALS AND METHODS: P. calleryana (PC) twigs and leaves were collected from the Matsu Islands, Taiwan, spanning 2018-2020. Extracts were prepared using 95% ethanol or water, and we assessed the chemical composition, total phenolic/triterpenoid contents and antioxidant properties. Metabolites were analysed via LC-MS/MS and molecular networking. Wound healing potential was evaluated on WS-1 cells through MTT and migration assays, and gene expression analyses, with tests including control (DMSO), compounds 1 (3'-hydroxylbenzyl-4-hydroxybenzoate-4'-O-ß-glucopyranoside) and 2 (vanilloylcalleryanin) (100 µM), and a positive control (ascorbic acid, 100 µM) for 24 h. RESULTS: Significant variations in extract compositions were observed based on the solvent used, with distinct metabolomic profiles in extracts collected during different months. Notably, compounds 1 and 2 showed no cytotoxic effects on human dermal fibroblast cells and significantly accelerated wound closure at 100 µM. A gene expression analysis indicated upregulation of wound healing-associated genes, including MMP-1 (matrix metalloproteinase-1) and COL1A1 (collagen, type 1, alpha 1). CONCLUSIONS: This study reports the first evidence of PC compounds aiding wound healing. Utilizing Global Natural Products Social Molecular Networking (GNPS) and principal component analysis (PCA) approaches, we unveiled metabolomic profiles, suggesting the potential to expedite wound-healing.


Asunto(s)
Extractos Vegetales , Pyrus , Cicatrización de Heridas , Cicatrización de Heridas/efectos de los fármacos , Humanos , Extractos Vegetales/farmacología , Pyrus/química , Estaciones del Año , Taiwán , Antioxidantes/farmacología , Hojas de la Planta , Espectrometría de Masas en Tándem , Línea Celular , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Movimiento Celular/efectos de los fármacos , Piel/metabolismo , Piel/efectos de los fármacos
2.
Front Med (Lausanne) ; 10: 1289144, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38111697

RESUMEN

Osteoporosis (OP) is a systemic metabolic skeletal disorder characterized by a decline in bone mass, bone mineral density, and deterioration of bone microstructure. It is prevalent among the elderly, particularly postmenopausal women, and poses a substantial burden to patients and society due to the high incidence of fragility fractures. Kidney-tonifying Traditional Chinese medicine (TCM) has long been utilized for OP prevention and treatment. In contrast to conventional approaches such as hormone replacement therapy, TCM offers distinct advantages such as minimal side effects, low toxicity, excellent tolerability, and suitability for long-term administration. Extensive experimental evidence supports the efficacy of kidney-tonifying TCM, exemplified by formulations based on the renowned herb Cornus officinalis and its bioactive constituents, including morroniside, sweroside, flavonol kaempferol, Cornuside I, in OP treatment. In this review, we provide a comprehensive elucidation of the underlying pathological principles governing OP, with particular emphasis on bone marrow mesenchymal stem cells, the homeostasis of osteogenic and osteoclastic, and the regulation of vascular and immune systems, all of which critically influence bone homeostasis. Furthermore, the therapeutic mechanisms of Cornus officinalis-based TCM formulations and Cornus officinalis-derived active constituents are discussed. In conclusion, this review aims to enhance understanding of the pharmacological mechanisms responsible for the anti-OP effects of kidney-tonifying TCM, specifically focusing on Cornus officinalis, and seeks to explore more efficacious and safer treatment strategies for OP.

3.
J Agric Food Chem ; 67(8): 2245-2254, 2019 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-30721044

RESUMEN

Chlorpyrifos is one of the most used organophosphorus insecticides. It is commonly degraded to 3,5,6-trichloro-2-pyridinol (TCP), which is water-soluble and toxic. Bacteria can degrade chlorpyrifos and TCP, but the biodegradation mechanism has not been well-characterized. Recently isolated Cupriavidus nantongensis X1T can completely degrade 100 mg/L chlorpyrifos and 20 mg/L TCP with half-lives of 6 and 8 h, respectively. We annotated a complete gene cluster responsible for TCP degradation in recently sequenced strain X1T. Two key genes, tcpA and fre, were cloned from X1T and transferred and expressed in Escherichia coli BL21(DE3). Degradation of TCP by X1T whole cell was compared with that by the enzymes 2,4,6-trichlorophenol monooxygenase and NAD(P)H:flavin reductase expressed and purified from E. coli BL21(DE3). Novel metabolites of TCP were isolated and characterized, indicating stepwise dechlorination of TCP, which was confirmed by TCP disappearance, mass balance, and detection and formation kinetics of chloride ion from TCP.


Asunto(s)
Proteínas Bacterianas/química , Cloropirifos/metabolismo , Cupriavidus/enzimología , FMN Reductasa/química , Insecticidas/metabolismo , Oxigenasas de Función Mixta/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Biodegradación Ambiental , Cloropirifos/química , Cupriavidus/química , Cupriavidus/genética , Cupriavidus/metabolismo , FMN Reductasa/genética , FMN Reductasa/metabolismo , Halogenación , Insecticidas/química , Cinética , Oxigenasas de Función Mixta/genética , Oxigenasas de Función Mixta/metabolismo
4.
J Biotechnol ; 227: 1-2, 2016 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-27063140

RESUMEN

Cupriavidus nantongensis X1 is a chlorpyrifos degrading bacterium, which was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. It is the first time to report the complete genome sequence of C. nantongensis species, which has been reported as a novel species of Cupriavidus genus. It could provide further pathway information in chlorpyrifos degradation.


Asunto(s)
Cloropirifos/metabolismo , Cupriavidus/genética , Cupriavidus/metabolismo , Genoma Bacteriano , Secuencia de Bases , Biodegradación Ambiental , ADN de Plantas/genética
5.
Int J Syst Evol Microbiol ; 66(6): 2335-2341, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27001671

RESUMEN

A Gram-stain-negative, aerobic, coccoid to small rod-shaped bacterium, designated X1T, was isolated from sludge collected from the vicinity of a pesticide manufacturer in Nantong, Jiangsu Province, China. Based on 16S rRNA gene sequence analysis, strain X1T belonged to the genus Cupriavidus, and was most closely related to Cupriavidus taiwanensis LMG 19424T (99.1 % 16S rRNA gene sequence similarity) and Cupriavidus alkaliphilus LMG 26294T (98.9 %). Strain X1T showed 16S rRNA gene sequence similarities of 97.2-98.2 % with other species of the genus Cupriavidus. The major cellular fatty acids of strain X1T were C16 : 0, C16 : 1ω7c and/or iso-C15 : 0 2-OH (summed feature 3), C18 : 1ω7c and C17 : 0 cyclo, and the major respiratory quinone was ubiquinone Q-8. The major polar lipids of strain X1T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, aminophospholipid, phospholipid and hydroxyphosphatidylethanolamine. The DNA G+C content was 66.6 mol%. The DNA-DNA relatedness values of strain X1T with the five reference strains C. taiwanensis LMG 19424T, C. alkaliphilus LMG 26294T, Cupriavidus necator LMG 8453T, Cupriavidus gilardii LMG 5886T and 'Cupriavidus yeoncheonense' KCTC 42053 were lower than 70 %. The results obtained from phylogenetic analysis, phenotypic characterization and DNA-DNA hybridization indicated that strain X1T should be proposed to represent a novel species of the genus Cupriavidus, for which the name Cupriavidus nantongensis sp. nov. is proposed. The type strain is X1T (=KCTC 42909T=LMG 29218T).


Asunto(s)
Cloropirifos/metabolismo , Cupriavidus/clasificación , Filogenia , Aguas del Alcantarillado/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , China , Cupriavidus/genética , Cupriavidus/aislamiento & purificación , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Ubiquinona/química
6.
Int J Syst Evol Microbiol ; 65(12): 4374-4380, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26354335

RESUMEN

A Gram-stain-negative, aerobic, yellow-pigmented and rod-shaped bacterium with a single polar flagellum or a stalk, designated strain RHGG3T, was isolated from rhizosphere soil of cultivated watermelon (Citrullus lanatus) collected from Hefei, China. Optimal growth of strain RHGG3T was observed at pH 7.0 and 28-30 °C. Cells were catalase-positive and oxidase-negative. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain RHGG3T belonged to the genus Caulobacter and showed the highest 16S rRNA gene sequence similarities to Caulobacter segnis ATCC 21756T (98.6 %), Caulobacter vibrioides CB51T (98.3 %) and Caulobacter henricii ATCC 15253T (97.2 %). The G+C content of the genomic DNA was 70 mol%. Strain RHGG3T contained Q-10 as the sole ubiquinone and the major fatty acids (>8 %) were 11-methyl C18 : 1ω7c, C18 : 1ω7c, C16 : 0, C15 : 0 and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). The polar lipids were various unknown glycolipids, phosphatidylglycerol and phosphoglycolipids. DNA-DNA relatedness of strain RHGG3T to type strains of the most closely related species (Caulobacter segnis ATCC 21756T, Caulobacter vibrioides DSM 4738 and Caulobacter henricii ATCC 15253T) was 32.4-40.9 %. Based on polyphasic taxonomy analysis (phylogenetic, unique phenotypic traits, chemotaxonomic and DNA-DNA hybridizations), strain RHGG3T represents a novel species of the genus Caulobacter, for which the name Caulobacter flavus sp. nov. is proposed. The type strain is RHGG3T ( = CGMCC 1.15093T = KCTC 42581T = JCM 30763T).


Asunto(s)
Caulobacter/clasificación , Filogenia , Rizosfera , Microbiología del Suelo , Técnicas de Tipificación Bacteriana , Composición de Base , Caulobacter/genética , Caulobacter/aislamiento & purificación , China , ADN Bacteriano/genética , Ácidos Grasos/química , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Ubiquinona/química
7.
J Hazard Mater ; 297: 17-24, 2015 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-25938642

RESUMEN

Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial strain being capable of degrading O,O-dialkyl phosphorothioate and O,O-dialkyl phosphate insecticides, designated as G1, was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis suggested that strain G1 belongs to the genus Stenotrophomonas. At an initial concentration of 50 mg/L, strain G1 degraded 100% of methyl parathion, methyl paraoxon, diazinon, and phoxim, 95% of parathion, 63% of chlorpyrifos, 38% of profenofos, and 34% of triazophos in 24 h. Orthogonal experiments showed that the optimum conditions were an inoculum volume of 20% (v/v), a substrate concentration of 50 mg/L, and an incubation temperature in 40 °C. p-Nitrophenol was detected as the metabolite of methyl parathion, for which intracellular methyl parathion hydrolase was responsible. Strain G1 can efficiently degrade eight organophosphorus pesticides (OPs) and is a very excellent candidate for applications in OP pollution remediation.


Asunto(s)
Compuestos Organofosforados/análisis , Plaguicidas/análisis , Aguas del Alcantarillado/microbiología , Stenotrophomonas/aislamiento & purificación , Contaminantes Químicos del Agua/análisis , Biodegradación Ambiental , Compuestos Organofosforados/química , Plaguicidas/química , ARN Ribosómico 16S/genética , Aguas del Alcantarillado/química , Stenotrophomonas/crecimiento & desarrollo , Contaminantes Químicos del Agua/química
8.
J Basic Microbiol ; 55(2): 229-35, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25470743

RESUMEN

In this study, a highly effective chlorpyrifos (CP)-degrading bacterium (termed strain X1) was isolated from the sludge of drain outlet of a chlorpyrifos manufacturer. Strain X1 was identified as Cupriavidus taiwanensis based upon the analysis of the 16S rDNA gene and biochemical characteristics, which is capable of transforming CP into 3,5,6-trichloro-2-pyridinol (TCP), and the resulting TCP was further metabolized when performed in an aqueous medium. Degradation experiments were carried out under different conditions at the range of pH (5.0∼9.0) and temperature (22∼42 °C), and the optimized pH and temperature were 7.0 and 32 °C respectively. Biotransformation of high concentration of CP was also determined; 400 mg l(À1) of CP was completely transformed within 36 h; approximately 95% of CP was removed within 48 h when concentration of CP was up to 500 mg l(À1) . A genomic library was successfully constructed to clone the gene encoding the CP hydrolase, and a positive transformant with clear hydrolytic zones was obtained and analyzed. The insert gene sequence exhibited close relationship with 99% similar to opdB gene encoding parathion hydrolase, whereas, transformant failed in degrading the accumulated TCP. These results highlight the potential of this bacterium to be used in the cleanup of CP.


Asunto(s)
Cloropirifos/metabolismo , Cupriavidus/aislamiento & purificación , Cupriavidus/metabolismo , Hidrolasas/genética , Piridonas/metabolismo , Aguas del Alcantarillado/microbiología , Biodegradación Ambiental , Biotransformación , Cupriavidus/clasificación , Cupriavidus/genética , ADN Ribosómico , Biblioteca Genómica , Hidrólisis , Filogenia
9.
J Microbiol ; 52(12): 1020-4, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25467119

RESUMEN

Wheat germ agglutinin (WGA), which is secreted on the surface of wheat root, has been defined as a protein that reversibly and non-enzymatically binds to specific carbohydrates. However, little attention has been paid to the function of WGA in the attachment of bacteria to their host plants. The aim of this study was to investigate the role of WGA in the attachment of Pseudomonas sp. WS32 to wheat roots. Wheat roots were initially treated with double-distilled water, WGA-H (WGA solution that was heated at 100°C for 15 min) and WGA, independently. Subsequently, the roots were co-incubated with cell solutions (109 cells/ml). A dilution plate method using a solid nutrient medium was employed to determine the adsorption of WS32 to wheat roots. WGA was labeled with fluorescein isothiocyanate and detected using the fluorescent in situ hybridization (FISH) technique. The number of adsorptive WS32 cells on wheat roots was significantly increased when the wheat roots were pretreated with WGA, compared with the control treatment (p = 0.01). However, WGA-H failed to increase the amount of bacterial cells that attached to the wheat roots because of the loss of its physiological activity. The FISH assay also revealed that more cells adhered to WGA-treated wheat roots than to control or WGA-H-treated roots. The results indicated that WGA can mediate Pseudomonas strain WS32's adherence to wheat seedling roots. The findings of this study provide a better understanding of the processes involved in plant-microbe interactions.


Asunto(s)
Raíces de Plantas/microbiología , Pseudomonas/fisiología , Plantones/microbiología , Triticum/microbiología , Aglutininas del Germen de Trigo , Adhesión Bacteriana , Hibridación Fluorescente in Situ , Raíces de Plantas/ultraestructura , Aglutininas del Germen de Trigo/aislamiento & purificación , Aglutininas del Germen de Trigo/metabolismo
10.
World J Microbiol Biotechnol ; 30(2): 423-8, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23975694

RESUMEN

To obtain amino acid-analogue-resistant mutants the wild strain A9 of Arthrospira platensis was mutated by ethylmethane sulfonate (EMS). Mutagenic effects of strain A9 by EMS were studied. The experimental results indicated that the survival rate curve of strain A9 took a typical "exponential shape" with lethal dosage of EMS being 1%. The survival of A9 strain was 13.2% when treated with 0.4% of EMS, and the resistant mutation rates to two amino acid analogues, ρ-fluorophenylalanine (FPA) and L-canavanine sulphate (CS), were greatly increased with the highest rates being at 4.9 × 10(-4) and 3.24 × 10(-4), respectively. By repeated screening, two stable mutants resistant to amino acid analogues, A9f resistant to FPA and A9c resistant to CS, were obtained. Resistances of the two mutants to corresponding amino acid-analogues were both significantly increased. Compared with their parent strain A9, A9f appeared larger than A9 performance in filament diameter, spiral diameter, spiral pitch, filament length and spiral number, and A9c showed much longer length and spiral pitch than those of the initial strain. Analysis results on amino acids compositions and contents showed that both two mutants accumulated quite higher concentration of amino acids in cells. The two mutants might be excellent high amino acids producing strain. By this means two useful mutants with stable genetic makers for further genetic study of A. platensis were obtained, which laid a good foundation for further study on the transformation of A. platensis.


Asunto(s)
Antibacterianos/metabolismo , Canavanina/metabolismo , Cianobacterias/efectos de los fármacos , Cianobacterias/metabolismo , Farmacorresistencia Bacteriana , Mutación , p-Fluorofenilalanina/metabolismo , Cianobacterias/citología , Cianobacterias/aislamiento & purificación , Mutagénesis
11.
J Microbiol ; 50(2): 191-8, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22538646

RESUMEN

Thirty-two isolates were obtained from wheat rhizosphere by wheat germ agglutinin (WGA) labeled with fluorescein isothiocyanate (FITC). Most isolates were able to produce indole acetic acid (65.6%) and siderophores (59.3%), as well as exhibited phosphate solubilization (96.8%). Fourteen isolates displayed three plant growth-promoting traits. Among these strains, two phosphate-dissolving ones, WS29 and WS31, were evaluated for their beneficial effects on the early growth of wheat (Triticum aestivum Wan33). Strain WS29 and WS31 significantly promoted the development of lateral roots by 34.9% and 27.6%, as well as increased the root dry weight by 25.0% and 25.6%, respectively, compared to those of the control. Based on 16S rRNA gene sequence comparisons and phylogenetic positions, both isolates were determined to belong to the genus Bacillus. The proportion of isolates showing the properties of plant growth-promoting rhizobacteria (PGPR) was higher than in previous reports. The efficiency of the isolation of PGPR strains was also greatly increased by WGA labeled with FITC. The present study indicated that WGA could be used as an effective tool for isolating PGPR strains with high affinity to host plants from wheat roots. The proposed approach could facilitate research on biofertilizers or biocontrol agents.


Asunto(s)
Bacterias/aislamiento & purificación , Técnicas de Tipificación Bacteriana/métodos , Raíces de Plantas/microbiología , Rizosfera , Microbiología del Suelo , Triticum/microbiología , Bacterias/química , Bacterias/clasificación , Bacterias/genética , ADN Bacteriano/genética , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/química , Datos de Secuencia Molecular , Filogenia , Raíces de Plantas/crecimiento & desarrollo , ARN Ribosómico 16S/genética , Triticum/crecimiento & desarrollo , Aglutininas del Germen de Trigo/química
12.
J Chromatogr B Analyt Technol Biomed Life Sci ; 878(3-4): 371-4, 2010 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-20015711

RESUMEN

Kombucha is a health tonic. D-saccharic acid-1,4-lactone (DSL), a component of kombucha, inhibits the activity of glucuronidase, an enzyme indirectly related with cancers. To date, there is no efficient method to determine the content of DSL in kombucha samples. In this paper, we report a rapid and simple method for the separation and determination of DSL in kombucha samples, using the high-performance capillary electrophoresis (HPCE) method with diode array detection (DAD). With optimized conditions, DSL can be separated in a 50 cm length capillary at a separation voltage of 20 kV in 40 mmol/L borax buffer (pH 6.5) containing 30 mmol/L SDS and 15% methanol (v/v). Quantitative evaluation of DSL was determined by ultraviolet absorption at lambda=190 nm. The relationship between the peak areas and the DSL concentrations, in a specified working range with linear response, was determined by first-order polynomial regression over the range 50-1500 microg/mL with a detection limit of 17.5 microg/mL. Our method demonstrated excellent reproducibility and accuracy with relative standard deviations (RSD) of less than 5% DSL content (n=5). This is the first report to determine DSL by HPCE. We have successfully applied this method to determine DSL in kombucha samples in various fermented conditions.


Asunto(s)
Medicamentos Herbarios Chinos/química , Electroforesis Capilar/métodos , Lactonas/análisis , Tampones (Química) , Calibración , Lactonas/química , Lactonas/aislamiento & purificación , Estándares de Referencia , Reproducibilidad de los Resultados
13.
Wei Sheng Wu Xue Bao ; 47(4): 706-9, 2007 Aug.
Artículo en Chino | MEDLINE | ID: mdl-17944377

RESUMEN

Monascus pigment is a natural, safe pigment and preservative. Six inhibitors of key enzymes from three metabolic pathways were chosen according to databases, and were used in basic medium to study their effects on the pigment synthesis in Monascus anka strain M5034. Trimethylamine, inhibitor of shikimic acid pathways, and anthranilic acid and 3,4-dihydroxybenzoic acid, inhibitors of mevalonic acid pathways, had no effects on the pigment biosynthesis. Pigment biosynthesis was severely inhibited by three inhibitors of the key enzymes in the polyketide pathways at the concentrations with no effects for growth of the strain. lodiacetamide (lower than 0.5 mmol/L), specific inhibitor of beta-ketoacyl-acylcarrier protein (ACP) synthase, reduced remarkably the pigment synthesis by 64.7%; 1.0 mmol/L imidazole, being nonspecific inhibitor of ACP synthase, could strongly suppress the synthesis of pigment by 60%, and 0.5 mmol/L 2,4-dinitrofluorobenzene, inhibiting the activity of thioesterase, strongly limited the pigment production with inhibitory extent up to 91.5%. All data implied that Monascus pigments might be synthesized through polyketide pathway.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Monascus/efectos de los fármacos , Monascus/metabolismo , Pigmentos Biológicos/biosíntesis , Vías Biosintéticas/efectos de los fármacos , Proteínas Fúngicas/metabolismo , Monascus/enzimología
14.
Ying Yong Sheng Tai Xue Bao ; 17(3): 557-9, 2006 Mar.
Artículo en Chino | MEDLINE | ID: mdl-16724762

RESUMEN

The study showed that the relationships between the specific growth rate (up) of Heterosigma akashiwo and the concentrations of nutrients nitrogen and phosphorus in water body accorded with Monod equation. H. akashiwo started to grow when the concentration of NO3(-)-N was higher than 7.5 mg x L(-1), and the specific growth rate (micro) of the algae was proportional to the concentration of NO3(-)-N between 3.75 to approximately 75 mg x L(-1). The maximum growth rate of H. akashiwo (micro/m-n) was 0.3475 x d(-1), and the half saturated constant (Ks-n) was 18.91 mg x L(-1). The specific growth rate of the alga was proportional to the concentration of PO4-P between 0 to approximately 1.0 mg x L(-1).The maximum growth rate of H. akashiwo ( microm-p) was 0.3024 x d(-1), and Ks-n was 0.4086 mg x L(-1). The most suitable growth conditions for H. akashiwo were 37.5 to approximately 225.0 mg x L(-1) NO3(-)-N, 5.0 to approximately 50.0 mg x L(-1) PO4-P, and N/P 25.


Asunto(s)
Eucariontes/crecimiento & desarrollo , Nitrógeno/farmacología , Fósforo/farmacología , Agua de Mar , Eucariontes/efectos de los fármacos , Biología Marina
15.
Ying Yong Sheng Tai Xue Bao ; 15(11): 2137-41, 2004 Nov.
Artículo en Chino | MEDLINE | ID: mdl-15707329

RESUMEN

A combination of field plot experiment and simulated low dosage accumulation test was adopted to study the ecological effects of low dosage mixed rare earth elements (REE) accumulation on major soil microbial groups in a yellow cinnamon soil. The continuous accumulation of REE had the alternative effects of stimulation, inhibition and re-stimulation on soil bacteria and actinomycetes, and a continuous stimulation on soil fungi. The inhibitory intensity of REE on the three groups of soil microorganisms was in the order of bacteria > actinomycetes > fungi. At the accumulation of 150 mg x kg(-1) of REE, the population structure of three groups changed remarkably. The number of REE-tolerant microbes increased, with gram negative bacteria, white spore group and penicillium being predominant in bacteria, actinomycetes and fungi population, respectively. The median effect concentration (EC50) of REE was 24.1, 41.6-73.8 and 55.3-150.1 mg x kg(-1) for soil bacteria, actinomycetes and fungi, respectively. The EC50 value of 30 mg x kg(-1) might be taken as the critical value of mixed REE in yellow cinnamon soil.


Asunto(s)
Ecosistema , Fertilizantes , Metales de Tierras Raras/análisis , Microbiología del Suelo , Contaminantes del Suelo/análisis , Suelo/análisis
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