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1.
Nat Prod Res ; 25(7): 684-95, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20623423

RESUMO

To further understand the hepatoprotective activity of Antrodia camphorata in living systems and the possible mechanisms of this protection, the effects of fractions from A. camphorata in submerged culture on the liver and its antioxidative system in acute ethanol intoxicated rats were investigated. The results showed that the ethanolic extract (Fr-I) of A. camphorata was the most effective in the prevention of ethanol-induced acute liver injury and free radical generation in rats. The ethanolic extract administrated prior to ethanol significantly prevented the increase in serum levels of hepatic enzyme markers such as aspartate aminotransferase and alanine aminotransferase. It also normalised the increase of hepatic malondialdehyde concentration and the decrease of glutathione levels in the liver. Moreover, Fr-I improved the ethanol-induced decrease of hepatic glutathione peroxidase and reductase activities. On the basis of these results, the ethanolic extract of A. camphorata may exert its hepatoprotective activity by up-regulating GSH-dependent enzymes and inhibiting free radical formation in the liver.


Assuntos
Antrodia/química , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Hepatopatias Alcoólicas , Extratos Vegetais/farmacologia , Alanina Transaminase/sangue , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Aspartato Aminotransferases/sangue , Etanol/efeitos adversos , Sequestradores de Radicais Livres/farmacologia , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/enzimologia , Fígado/patologia , Hepatopatias Alcoólicas/tratamento farmacológico , Hepatopatias Alcoólicas/prevenção & controle , Masculino , Malondialdeído/metabolismo , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley
2.
Food Chem ; 127(2): 662-8, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23140716

RESUMO

In this work a headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry (GC-O) was developed to evaluate the profile of the volatile compounds that contribute to the aroma of Antrodia camphorata in submerged culture. For this purpose, the HS-SPME sampling method for the volatile compounds of A. camphorata in submerged culture was optimised by a D-optimal design. A HS extraction of the culture broth of A. camphorata followed by incubation on a carboxen/polydimethylsiloxane (CAR/PDMS) fibre during 31.8min at 54.6°C gave the most effective and accurate extraction of the volatile compounds. By the optimised method, a total of 49 volatile compounds were identified in culture broth of A. camphorata, while a total of 55 volatile compounds were identified in the mycelia. A series of C(8) aliphatic compounds (mushroom-like odour), several lactones (fruity odour) and l-linalool (citrus-like odour) were the most potent key odourant in both the mycelia and culture broth. This combined technique is fast, simple, sensitive, inexpensive and useful to monitor volatile compounds associated to A. camphorata.

3.
Appl Microbiol Biotechnol ; 83(2): 233-9, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19172266

RESUMO

The co-culture of the suspension cells of Taxus chinensis var. mairei and its endophytic fungi, Fusarium mairei, in a 20-L co-bioreactor was successfully established for paclitaxel production. The co-bioreactor consists of two-unit tanks (10 L each) with a repairable separate membrane in the center, culturing Taxus suspension cells in one tank and growing fungi in another. By optimizing the co-culture conditions, there was a desirable yield of paclitaxel in Taxus cell cultures. The Taxus cell cultures by co-culture produced 25.63 mg/L of paclitaxel within 15 days; it was equivalent to a productivity of 1.71 mg/L per day and 38-fold higher than that by uncoupled culture (0.68 mg/L within 15 days). The optimum conditions for co-culture in the co-bioreactor were: B5 medium, inoculating fungi when Taxus cells had grown for 5 days in the co-bioreactor, hydrophilic separate membrane in the center of the co-bioreactor, and air flow rate of 1:0.85 v/v/m in fungus cultures.


Assuntos
Antineoplásicos Fitogênicos/biossíntese , Reatores Biológicos , Técnicas de Cultura/métodos , Fungos/metabolismo , Paclitaxel/biossíntese , Taxus/metabolismo , Reatores Biológicos/microbiologia , Células Cultivadas , Técnicas de Cocultura , Meios de Cultura/metabolismo , Fungos/crescimento & desenvolvimento , Taxus/microbiologia
4.
Cell Biol Int ; 33(1): 106-12, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18996212

RESUMO

Endophytic fungi (Fusarium mairei) culture broth (EFCB) was added to cell suspension cultures of Taxus cuspidata. After 5 days, cultures of T. cuspidata given 4 ml of EFCB produced a maximal yield of 6.11 mg/l paclitaxel, with a release ratio of 75%, 2- and 6.8-fold, respectively, greater than the controls. The active element in EFCB is an exopolysaccharide of approximately 79 kD. Endophytic fungi produced 0.19 mg/l of paclitaxel in its producing medium. However, when the supernatant of Taxus cell suspension cultures from day 20 was added to the paclitaxel-producing medium, the biomass of fungi decreased by 24% and the yield of paclitaxel by 45%. In a co-culture system of plant and fungus, the yield of paclitaxel (12.8 mg/l) was >2-fold higher than that in the EFCB-treatment system.


Assuntos
Fungos/metabolismo , Paclitaxel/biossíntese , Taxus/microbiologia , Técnicas de Cultura de Células , Células Cultivadas , Fungos/crescimento & desenvolvimento , Paclitaxel/análise , Folhas de Planta , Taxus/crescimento & desenvolvimento , Fatores de Tempo
5.
Biotechnol Lett ; 30(2): 349-56, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17989927

RESUMO

A novel macrolide, isolated from the myxobacteria Sorangium cellulosum WXNXJ-C, was identified as 1,7,12,13-tetrahydroxy-14-methoxy-8,10-dimethyl-6-phenyl-5,15-dioxa-bicyclo[9.3.1]pentadecan-4-one, "Phoxalone". It had minimum IC(50) values of 0.24, 6.9, 10.3, 0.98 and 4 microg/ml, respectively, against tumour cell lines: B16, Bel7402, H446, MCF-7, and SGC7901. In addition, it had less cytotoxicity to normal human liver L02 cell lines (286 microg/ml, 24 h). A cytotoxic bioactivity study on H446 cell line in vitro suggested that Phoxalone arrested the mitosis in the G2/M phase.


Assuntos
Antineoplásicos/química , Macrolídeos/química , Myxococcales/química , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/isolamento & purificação , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Cromatografia Gasosa-Espectrometria de Massas , Hepatócitos/efeitos dos fármacos , Humanos , Macrolídeos/isolamento & purificação , Macrolídeos/uso terapêutico , Camundongos , Estrutura Molecular , Myxococcales/genética
6.
Huan Jing Ke Xue ; 29(12): 3439-44, 2008 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-19256382

RESUMO

Ozonation was applied to investigate the removal efficiency of 6 odorous organic compounds in eutrophic water from Taihu Lake (Wuxi). The results showed that the ozonation process could be described by first order kinetic model and the overall kinetic rates of the odorous compounds were determined by their chemical characteristic and structure, which could be ranked: beta-Ionone (3.3 x 10(-3) s(-1)) > beta-Cyclocitral (2.8 x 10(-3) s(-1)) > 2,4-Decadienal (2.7 x 10(-3) s(-1)) > Neryl Acetone (2.2 x 10(-3) s(-1)) > Geosmin (1.4 x 10(-3) s(-1)) > 2-Methylisoborneol (5.6 x 10(-4) s(-1)). Ozonation of eutrophic water led to the formation of a series of aldehydes, ketones, alcohols and esters. The influence of bicarbonate and natural organic carbon on odorous compounds ozonation were further investigated, results showed that the bicarbonate could restrain the effect of ozonation by cutting down the radical pathway and natural organic carbon in the water by competition with target compounds.


Assuntos
Eutrofização , Odorantes/análise , Compostos Orgânicos/química , Ozônio/química , Purificação da Água/métodos , China , Água Doce/análise , Cinética , Compostos Orgânicos/análise , Oxirredução , Poluição da Água/análise
7.
Nat Prod Res ; 21(14): 1256-65, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18075888

RESUMO

A myxobacterium strain AHB125 belonging to genus Sorangium cellulosum was isolated from Anhui area in China and identified with morphological analysis by electron microscopy and phase contrast microscope according to Bergey's manual of systematic bacteriology (8th Ed.). Its high-antitumor bioactivity metabolites was evaluated by bioassay-directed screening technique with B16 tumor cell line etc. Research results showed that it exhibited not only strong antitumor ability bioactivities and broad-spectrum antitumor abilities to B16, Bel7402, H446, SGC7901 cell lines, but also has selectivity and pertinence to B16 and SGC7901 cell lines. The compound was confirmed as epothilone B by HPLC and LC/MS analysis, compared to the epothilone B standard sample. Bioassay indicated that there were other high-bioactive substances in the metabolites.


Assuntos
Antineoplásicos/farmacologia , Epotilonas/farmacologia , Myxococcales/metabolismo , Animais , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida , Epotilonas/química , Epotilonas/isolamento & purificação , Humanos , Camundongos , Estrutura Molecular , Myxococcales/química , Espectrometria de Massas por Ionização por Electrospray
8.
Nat Prod Res ; 21(14): 1271-85, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18075890

RESUMO

A novel macrolide with dioxa and double ring pentadecanone, named as phoxalone, isolated from the culture broth of a myxobacterium Sorangium cellulosum WXNXJ-C, was well investigated. The chemical structure of Phoxalone was elucidated by spectroscopic analysis including UV, IR, (1)H NMR, MALDI-TOF-MS, and LC/MS spectra. The results of cytotoxic bioactivities on human non-small lung cancer H446, in vitro, showed that not only did phoxalone express higher antitumor bioactivity than many antitumor drugs, but it also displayed less cytotoxicity to normal human liver L02 cell lines (IC(50), 286 microg mL(-1)). Further cytotoxic bioactivity study indicated that phoxalone could induce H446 cell line apoptosis in vitro. More investigation results of flow-cytometric analysis suggested that phoxalone arrested the mitosis of H446 cell line at G2/M phase. Hence, phoxalone and its derivatives or analogs would reveal huge research value and fascinating foreground.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Macrolídeos/farmacologia , Relação Estrutura-Atividade , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Humanos , Macrolídeos/química , Macrolídeos/isolamento & purificação , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Microscopia Eletrônica de Varredura , Microscopia de Contraste de Fase , Estrutura Molecular , Myxococcales/química , Myxococcales/metabolismo , Estereoisomerismo
9.
Toxicol In Vitro ; 21(3): 417-27, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17150327

RESUMO

The biological function of GFPPS1b, a novel polysaccharide-peptide isolated from cultured mycelia of Grifola frondosa GF9801, was well investigated. GFPS1b has anti-tumor activity and can significantly inhibit the proliferation of SGC-7901 cells, whereas slightly influences the growth of human normal liver cell line L-02. When treated with GFPS1b, SGC-7901 cells showed typical apoptotic morphological features such as the loss of villus and appearance of apoptotic bodies on the cell surface, volume reduction, and chromatin condensation, by scanning electron microscopy (SEM) and fluorescent microscopy (Hoechst 33342). The results of flow cytometry analysis and annexin V-PI assay showed that the SGC-7901 cell cycle was arrested in the G(2)/M phase, the subdiploid peak of DNA characteristic of apoptotic was also observed, and the apoptosis ratio was about 15.08%. DNA isolated from SGC-7901 cells cultured with GFPS1b showed a typical DNA 'ladders' of apoptosis in agarose gel electrophoresis. Further investigation results showed that the apoptotic machinery of SGC-7901 induced by GFPS1b was associated with drop in mitochondrial trans-membrane potential, upregulation of Bax, downregulation of Bcl-2, and activation of caspase-3. Our finding suggests that GFPS1b could suppress SGC-7901 cell growth and reduce cell survival via arresting cell cycle and inducing apoptosis of tumor cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Grifola/química , Polissacarídeos/farmacologia , Proteoglicanas/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA , Ensaios de Seleção de Medicamentos Antitumorais , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Grifola/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/ultraestrutura , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Micélio/química , Extratos Vegetais/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
10.
Appl Microbiol Biotechnol ; 74(1): 239-43, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17086413

RESUMO

The strain Aspergillus fumigatus XC6 isolated from mildewing rice straw was evaluated for its ability to decolorize a dye industry effluent. The strain was capable of decolorizing dyes effluent over a pH range 3.0-8.0 with the dyes as sole carbon and nitrogen sources. The optimum pH was 3.0; however, supplemented with either appropriate nitrogen sources (0.2% NH(4)Cl or (NH(4))(2)SO(4) ) or carbon sources (1.0% sucrose or potato starch), the strain decolorized the effluent completely at the original pH of the dyes effluent. Therefore, A. fumigatus XC6 is an efficient strain for the decolorization of reactive textile dyes effluents, and it might be a practical alternative in dyeing wastewater treatment.


Assuntos
Aspergillus fumigatus/metabolismo , Corantes/metabolismo , Resíduos Industriais , Indústria Têxtil , Eliminação de Resíduos Líquidos/métodos , Aspergillus fumigatus/crescimento & desenvolvimento , Biodegradação Ambiental , Carbono/metabolismo , Concentração de Íons de Hidrogênio , Nitrogênio/metabolismo
11.
J Ethnopharmacol ; 110(1): 160-4, 2007 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-17092673

RESUMO

The hepatoprotective effects of the mycelia of Antrodia camphorata and Armillariella tabescens were evaluated in vivo using acute ethanol-intoxicated rats as an experimental model. Animals were orally treated with Antrodia camphorata (0.5 or 1.0 g/kg b.w.) or Armillariella tabescens (0.5 or 1.0 g/kg b.w.) for 10 days whereas controls received vehicle only. At the end of the experimental 10-day period, the animals were administered by gavage with an acute ethanol dose of 5.0 g/kg b.w. diluted in deionized water (6:4, v/v) and sacrificed at 18 h after ethanol administration. The degree of protection was measured by using biochemical parameters like serum transaminases (AST and ALT), alkaline phosphatase (ALP), bilirubin. Meanwhile, the histopathological studies were carried out to support the above parameters. Administration of Antrodia camphorata or Armillariella tabescens markedly prevented ethanol-induced elevation of levels of serum AST, ALT, ALP, and bilirubin comparable with standard drug silymarin.


Assuntos
Hepatopatias Alcoólicas/terapia , Micélio , Substâncias Protetoras/farmacologia , Animais , Terapia Biológica/métodos , Ensaios Enzimáticos Clínicos , Etanol/administração & dosagem , Etanol/farmacologia , Fungos , Hepatopatias Alcoólicas/prevenção & controle , Polyporales , Substâncias Protetoras/administração & dosagem , Ratos , Ratos Wistar
12.
Zhongguo Zhong Yao Za Zhi ; 31(17): 1457-60, 2006 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-17087091

RESUMO

OBJECTIVE: To study the growth inhibition of Weikangfu recipe on S180 tumor and its apoptotic induction. METHOD: S180-bearing mice were orally administrated with different dosages of Weikangfu recipe, and the growth inhibition was evaluated; apoptotic cells induced were detected by flow cytometry and DNA agarose gel electrophoresis. RESULT: Weikangfu recipe showed significant inhibition on the growth of S180 tumor in a dose-dependent manner, compared with the control group. From apoptotic analyses, Weikangfu recipe induced a dose-dependent apoptosis of S180 tumor cells and arrested the cell cycle distribution at G0-G1 phase. At the same time, the up-regulation of p53 and bax and down-regulation of bcl-2 were observed in S180 tumor cells of the treated groups. CONCLUSION: Our findings demonstrate that Weikangfu recipe can significantly inhibit the growth of S180 tumor and induce apoptosis through expression alteration of p53, bax and bcl-2.


Assuntos
Apoptose/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Plantas Medicinais , Sarcoma 180/patologia , Animais , Ciclo Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/isolamento & purificação , Feminino , Masculino , Camundongos , Transplante de Neoplasias , Plantas Medicinais/química , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Distribuição Aleatória , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo
13.
Zhong Yao Cai ; 29(7): 689-91, 2006 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-17059010

RESUMO

OBJECTIVE: To supply the scientific basis of research and development of the medicinal value of Polygonum cuspidatum. METHODS: One composition was isolated from the roots of Polygonum cuspidatum by cytotoxicity based fractionation and identified by HPLC-MS, UV scanning and IR. The inhibition and morphology of L-02, Hep G2, SHZ-888, MCF-7, MCF-7/ADM cells growth caused by this composition was determined by MTT assay and HE dyeing. RESULTS: This composition was identified as trans-and cis-resveratrol. It could specifically inhibit proliferation of many cancer cells but not human normal liver cell. We investigated the cytotoxicity of resveratrol to adriamycin-resistant MCF-7 cell in virtro. CONCLUSION: Resveratrol is a new anticancer composition which is less toxicity and higher efficiency in Polygonum cuspidatum.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Fallopia japonica/química , Plantas Medicinais/química , Estilbenos/farmacologia , Animais , Neoplasias da Mama/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Feminino , Humanos , Neoplasias Hepáticas/patologia , Ratos , Resveratrol , Rizoma/química , Estilbenos/administração & dosagem , Estilbenos/isolamento & purificação
14.
Acta Biochim Biophys Sin (Shanghai) ; 38(5): 342-8, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16680375

RESUMO

Resveratrol, a plant polyphenol, is found in significant amounts in the skin of grapes and in some traditional herbs. It is reported to exert different biological activities, such as inhibiting lipid peroxidation, scavenging free radicals, inhibiting platelet aggregation, and anticancer activity. In order to screen the resveratrol-binding proteins, we synthesized biotinylated resveratrol, purified by liquid chromatography and immobilized it into streptavidin-coated microplate wells. 3-(4,5-Demethylthiazol-)-2,5-diphenyl tetrazolium bromide assay showed little change in the anticancer activity of biotinylated resveratrol in vitro. A random library of phage-displayed peptides was screened for binding to immobilized resveratrol to isolate resveratrol-binding proteins. Several peptides were found to bind to resveratrol specifically, which was proven by enzyme-linked immunosorbent assay. Through amino acid sequence analysis of the selected peptides and human proteins using the BLAST program, the results showed that resveratrol has an affinity for various proteins such as breast cancer-associated antigen, breast cancer resistance protein, death-associated transcription factor, and human cyclin-dependent kinase. These results demonstrate that our study provides a feasible method for the study of binding proteins of natural compounds using a phage-displayed random peptide library.


Assuntos
Neoplasias da Mama/metabolismo , Mama/metabolismo , Glândulas Mamárias Humanas/metabolismo , Biblioteca de Peptídeos , Peptídeos/administração & dosagem , Peptídeos/metabolismo , Estilbenos/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/métodos , Humanos , Glândulas Mamárias Humanas/patologia , Resveratrol
15.
J Environ Sci (China) ; 18(1): 125-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-20050560

RESUMO

Effect of cerium (Ce3+) on the growth, photosynthesis and antioxidant enzyme system in rape seedlings (Brassica juncea L.) exposed to two levels of UV-B radiation (T1: 0.15 W/m2 and T2: 0.35 W/m2) was studied by hydroponics under laboratory conditions. After 5 d of UV-B treatment, the aboveground growth indices were obviously decreased by 13.2%-44.1% (T1) and 21.4%-49.3% (T2), compared to CK, and except active absorption area of roots, the belowground indices by 14.1%-35.6% (T1) and 20.3%-42.6% (T2). For Ce+UV-B treatments, the aboveground and belowground growth indices were decreased respectively by 4.1%-23.6%, 5.2% -23.3% (Ce+T1) and 10.8%-28.4%, 7.0%-27.8% (Ce+T2), lower than those of UV-B treatments. The decrease of growth indices appeared to be the result of changes of physiological processes. Two levels of UV-B radiation induced the decrease in chlorophyll content, net photosynthesis rate, transpiration rate, stomatal conductance and water use efficiency by 11.2%-25.9% (T1) and 20.9%-56.9% (T2), whereas increase in membrane permeability and activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) by 6.9%, 22.8%, 21.5%, 9.5% (T1) and 36.6%, 122.3%, 103.5%, 208.9% (T2), respectively. The reduction of the photosynthetic parameters in Ce+UV-B treatments was lessened to 3.2%-13.8% (Ce+T1) and 4.9%-27.6% (Ce+T2), and the increase of membrane permeability and activities of antioxidant enzymes except POD in the same treatments were lessened to 2.4%, 8.4%, 6.6% (Ce+T1) and 30.1%, 116.7%, 75.4% (Ce+T2). These results indicate that the regulative effect of Ce on photosynthesis and antioxidant enzymatic function is the ecophysiological basis of alleviating the suppression of UV-B radiation on growth of seedlings. Furthermore, the protective effect of Ce on seedlings exposed to T1 level of UV-B radiation is superior to T2 level.


Assuntos
Cério/farmacologia , Plantas/efeitos dos fármacos , Plantas/efeitos da radiação , Raios Ultravioleta , Fotossíntese/efeitos dos fármacos , Desenvolvimento Vegetal
16.
Sheng Wu Gong Cheng Xue Bao ; 21(3): 407-13, 2005 May.
Artigo em Chinês | MEDLINE | ID: mdl-16108365

RESUMO

Microbial xylanases have received a great deal of attention in the last two decades for their potential applications in food, paper making and animal feed industries. Bacillus pumilus WL-11 was identified as a producer of alkane xylanase free of cellulase after screening soil samples of paper-making factories. The xylanase A (XylA) was purified to homogeneity from the culture filtrate of Bacillus pumilus WL-11 by (NH4) 2SO4 precipitation, CM-Sephadex and Sephadex G-75 chromatographies. The molecular mass of XylA is estimated to be 26.0 kD by SDS-PAGE and its isoelectric point is 9.5. The apparent Km is 16.6 mg/mL and V(max) is 1263 micromol/(min x mg) towards oat spelt xylan. XylA is optimally active between pH 7.2 and 8.0, and stable at pH 6.0 to 10.4. The enzyme is optimally active at 45 degrees C - 55 degrees C and stable at temperature below 45 degrees C, with its half time of activity of 35 min and 15 min at 55 degrees C and 60 degrees C respectively. HPLC analysis revealed that hydrolysis patterns of xylans from oat spelt, birch wood and beech wood by purified XylA were different. The XylA is determined to be an endo-beta-1,4-xylanase, as it generated mainly xylotriose and no xylose was detected among the three hydrolysates. XylA has strong hydrolytic activity towards the pentose in the hydrolysates of beech wood and birch wood xylans, but was not active to the pentose in the hydrolysate of oat spelt xylan. The crude WL-11 enzyme can efficiently hydrolyze oat spelt xylan to a series of xylo-oligosaccharides, suggesting its potential application in nutraceutical industry.


Assuntos
Bacillus/enzimologia , Proteínas de Bactérias/metabolismo , Endo-1,4-beta-Xilanases/metabolismo , Bacillus/classificação , Meios de Cultura , Endo-1,4-beta-Xilanases/isolamento & purificação , Especificidade por Substrato
17.
Wei Sheng Wu Xue Bao ; 45(2): 258-63, 2005 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-15989272

RESUMO

The psychrotrophs SYP-A2-3 producing the cold-adapted protease has been isolated from the bacterial samples collected from the No. 1 Glacier of China and identified as Bacillus cereus according to its morphological and physiochemical characteristics and 16s rDNA gene sequence analysis. It could grow between 0 degree C and 38 degrees C while its optimal growth temperature was 25 degrees C and the optimal temperature for its protease production was 15 degrees C. The cold-adapted protease was identified as neutral metallo-protease, the molecular weight was 34.2 kD shown by SDS-PAGE, the optimal pH and temperature for activity was 7.0-8.5 and 42 degrees C, respectively. Various fermentation conditions of its protease production were also investigated. The results showed that casein was the best nitrogen source while glucose and starch were suitable carbon source for its protease production. The initial pH of fermentation broth ranged from 6.5 to 7.0 was optimal. Under optimized conditions, the protease activity produced by SYP-A2-3 could reach 3800 U/mL and 4800 U/mL conducted in shaking flask and 5 L stirred jar experiment, respectively.


Assuntos
Bacillus cereus/classificação , Bacillus cereus/enzimologia , Metaloproteases/biossíntese , Bacillus cereus/crescimento & desenvolvimento , Bacillus cereus/isolamento & purificação , Meios de Cultura , Estabilidade Enzimática , Fermentação , Concentração de Íons de Hidrogênio , Metaloproteases/química , Metaloproteases/metabolismo , Peso Molecular , Temperatura
18.
J Environ Sci (China) ; 17(6): 1038-41, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16465904

RESUMO

Effects of the simulated acid rain (AR) and ultraviolet-B (UV-B, 280-320 nm) radiation with a single or two ways simultaneously (AR + UV-B) on the antioxidant enzyme and photosynthesis of the rape seedlings were investigated by the hydroponic culture. The results of static experiment indicated that the tolerance of rape seedling to single stress (AR or UV-B) is stronger than that to dual stresses (AR + UV-B). Furthermore, the dual stresses had additive effect on catalase activity, and a synergistic effect on MDA content, net photosynthesis rate, water use efficiency as well as intercellular CO2 concentration. Meanwhile, it has an independent effect on chlorophyll content, stomatal conductance, and transpiration rate as well as membrane permeability. During 64 h restoration course, the dynamic change in the curves of physiological and biochemical indices were not identical, and none of them show a simple linear variation. According to the static and dynamic experiments, it was found that a responsive sequence of catalase activity, membrane permeability, MDA content and photosynthetic characteristics to the above-mentioned stresses was as follows: AR + UV-B > UV-B > AR.


Assuntos
Chuva Ácida/toxicidade , Catalase/metabolismo , Mostardeira , Fotossíntese/efeitos dos fármacos , Fotossíntese/efeitos da radiação , Raios Ultravioleta , Dióxido de Carbono/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos da radiação , China , Transpiração Vegetal/efeitos dos fármacos , Transpiração Vegetal/efeitos da radiação , Fatores de Tempo
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