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1.
Quant Imaging Med Surg ; 13(4): 2426-2440, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-37064370

RESUMEN

Background: The sensitivity and correlation of coronary computed tomography angiography (CTA) as compared with histopathology are unknown in evaluating coronary arterial calcification. In this study, we retrospectively evaluated qualitatively and quantitatively the sensitivity and correlation of coronary CTA compared with histopathology in assessing coronary arterial calcification. Methods: This study was conducted on 12 randomly selected cadavers aged over 40 years at the time of death, and 53 segments of coronary arteries from these 12 cadavers were obtained from the Human Anatomy Laboratory of Tianjin Medical University. The artery segments were scanned using contrasted-enhanced dual-source computed tomography (DSCT) with an axial slice thickness of 0.6 mm. Coronary artery calcification in a coronary segment was defined as the presence of 1 or more voxels with a CT density >130 Hounsfield units. According to the arc of calcification in the cross section of the coronary artery wall, calcified plaques were divided into three categories: mild, moderate, and severe calcification. The coronary artery stenosis caused by calcified plaque was observed and calculated with multiplanar reconstruction (MPR), maximum density projection, volume rendering (VR), and cross-sectional reconstruction. After CT enhancement scanning, the coronary artery specimens were cut into 4-mm long segments and embedded in paraffin for pathological staining. Pathological classification and coronary artery stenosis measured with pathological analysis were used as comparison criteria. Results: Histopathology detected 69 Vb-type plaques, while DSCT detected 57 calcified plaques. The sensitivity of CT for detecting mild, moderate, and severe calcified plaques were 88.3% [95% confidence interval (CI): 74.1-95.6%], 100% (95% CI: 69.8-100%), and 100% (95% CI: 73.2-100%), respectively. DSCT had a significant (P<0.001) correlation with histopathology in quantifying coronary artery stenosis caused by mild, moderate, and severe calcified plaques (R2=0.9278, R2=0.9158, R2=0.7923, respectively). Compared with histopathology, DSCT overestimated coronary artery stenosis caused by mild, moderate, and severe calcified plaques (3.2%±2.0%, 4.9%±4.7%, and 14.7%±8.2%, respectively; P<0.05). Conclusions: DSCT contrast enhancement scanning can detect and characterize coronary artery calcification with a good correlation with histopathologic quantification of coronary artery stenosis caused by different types of calcified plaques, even though coronary CTA may overestimate the stenosis.

2.
Front Microbiol ; 14: 1139406, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37032872

RESUMEN

Broad bean paste-meju was fermented by a mixture of broad bean koji and saline; koji fermentation is an essential process for the production of broad bean paste-meju. Aspergillus oryzae was the most widely used in sauce fermentation. The purpose of this study was to research the factory adaptability of the highly efficient A. oryzae PNM003 and further evaluate the effect of fermentation conditions and fermentation strains on koji. A. oryzae PNM003 was compared with the widely used strain HN 3.042 not only in the laboratory but also in factory conditions (large scale). Results showed that the koji made with the same starter in the factory had a greater amount of fungi than that in the laboratory. Bacteria and yeast levels in HN_L koji were higher than in PN_L koji. As for fungi constitution, almost only Aspergillus survived in the end through the microorganism self-purification process during koji fermentation. As for the bacterial constitution, koji was grouped by fermentation conditions instead of fermentation starter. PN koji had higher protease activity and a higher content of total acids, amino acid nitrogen, amino acids, and organic acids in the laboratory conditions. Nevertheless, in factory conditions, PN koji and HN koji had similar indexes. As for volatile flavor compounds, koji made with the two starters in the same condition was grouped together. As for the same starter, there were more flavor compounds metabolized in the factory condition than in the laboratory condition, especially esters and alcohols. The results showed PN was a highly efficient strain to ferment koji, but the advantages were expressed more remarkably in laboratory conditions. In brief, the fermented condition had a greater influence than the fermentation starter for broad bean koji.

4.
J Agric Food Chem ; 69(26): 7409-7419, 2021 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-34180240

RESUMEN

An increasing number of Bacillus strains have been identified, and the removal capacity of zearalenone (ZEN) was determined; however, they failed to reveal the detoxification mechanism and transformation product. Here, Bacillus subtilis Y816, which could transform 40 mg/L of ZEN within 7 h of fermentation, was identified and studied. First, the biotransformation products of ZEN and 17-ß-estradiol (E2) were identified as ZEN-14-phosphate and E2-3-phosphate by HPLC-TOF-MS and NMR, respectively. An intracellular zearalenone phosphotransferase (ZPH) was found through transcriptome sequencing analysis of B. subtilis Y816. The phosphorylated reaction conditions of ZEN by ZPH were further revealed in this work. Furthermore, the phosphorylated conjugates showed reduced estrogenic toxicity compared with their original substances (ZEN and α/ß-zearalenol) using an engineered yeast biosensor system. The first report on the phosphorylated conjugated mode of ZEN in B. subtilis Y816 will inspire new perspectives on the biotransformation of ZEN in Bacillus strains.


Asunto(s)
Bacillus , Zearalenona , Bacillus/metabolismo , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Biotransformación , Fermentación , Zearalenona/metabolismo
5.
J Biosci Bioeng ; 126(4): 470-477, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29805115

RESUMEN

trans-4-Hydroxy-l-proline (trans-4Hyp) is widely used as a valuable building block for the organic synthesis of many pharmaceuticals such as carbapenem antibiotics. The major limitation for industrial bioproduction of trans-4Hyp is the low titer and productivity by using the existing trans-proline 4-hydroxylases (trans-P4Hs). Herein, three new trans-P4Hs from Alteromonas mediterranea (AlP4H), Micromonospora sp. CNB394 (MiP4H) and Sorangium cellulosum (ScP4H) were discovered through genome mining and enzymatic determination. These trans-P4Hs were introduced into an l-proline-producing chassis cell, and the recombinant strain overexpressing AlP4H produced the highest concentration of trans-4Hyp (3.57 g/L) from glucose in a shake flask. In a fed-batch fermentation with a 5 L bioreactor, the best strain SEcH (pTc-B74A-alp4h) accumulated 45.83 g/L of trans-4Hyp within 36 h, with the highest productivity (1.27 g/L/h) in trans-4Hyp fermentation from glucose, to the best of our knowledge. This study provides a promising hydroxylase candidate for efficient industrial production of trans-4Hyp.


Asunto(s)
Proteínas Bacterianas/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Glucosa/metabolismo , Hidroxiprolina/biosíntesis , Oxigenasas de Función Mixta/genética , Alteromonas/enzimología , Proteínas Bacterianas/metabolismo , Reactores Biológicos , Fermentación , Ingeniería Metabólica , Micromonospora/enzimología , Oxigenasas de Función Mixta/metabolismo , Prolina/metabolismo
6.
Proteomics ; 17(17-18)2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28792668

RESUMEN

Medicinal mushroom Antrodia camphorata sporulate large numbers of arthroconidia in submerged fermentation, which is rarely reported in basidiomycetous fungi. Nevertheless, the molecular mechanisms underlying this asexual sporulation (conidiation) remain unclear. Here, we used comparative transcriptomic and proteomic approaches to elucidate possible signaling pathway relating to the asexual sporulation of A. camphorata. First, 104 differentially expressed proteins and 2586 differential cDNA sequences during the culture process of A. camphorata were identified by 2DE and RNA-seq, respectively. By applying bioinformatics analysis, a total of 67 genes which might play roles in the sporulation were obtained, and 18 of these genes, including fluG, sfgA, SfaD, flbA, flbB, flbC, flbD, nsdD, brlA, abaA, wetA, ganB, fadA, PkaA, veA, velB, vosA, and stuA might be involved in a potential FluG-mediated signaling pathway. Furthermore, the mRNA expression levels of the 18 genes in the proposed FluG-mediated signaling pathway were analyzed by quantitative real-time PCR. In summary, our study helps elucidate the molecular mechanisms underlying the asexual sporulation of A. camphorata, and provides also useful transcripts and proteome for further bioinformatics study of this valuable medicinal mushroom.


Asunto(s)
Antrodia/crecimiento & desarrollo , Antrodia/metabolismo , Proteínas Fúngicas/metabolismo , Proteoma/metabolismo , Transducción de Señal , Esporas Fúngicas/metabolismo , Antrodia/genética , Regulación Fúngica de la Expresión Génica , Proteómica/métodos , Reproducción Asexuada , Transcriptoma
7.
J Int Med Res ; 44(4): 865-74, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27278556

RESUMEN

OBJECTIVE: To investigate the possible association between plasma proprotein convertase subtilisin/kexin type 9 (PCSK9) and the incidence and severity of calcific aortic valve disease (CAVD). METHODS: This prospective, cross sectional study involved patients with and without (controls) aortic valve calcification diagnosed by transthoracic echocardiography and dual source computed tomography (DSCT) scan. Aortic valves calcification scores were calculated from DSCT scans and patients were graded: grade 1, no calcification; grade 2, mildly calcified; grade 3, moderately calcified; grade 4, heavily calcified. Plasma PCSK9 levels were measured using an enzyme-linked immunosorbent assay. RESULTS: Forty patients were grade 1 (controls), 32 were grade 2, 48 were grade 3 and 32 were grade 4. Plasma levels of PCSK9 were significantly different between the four groups and the highest value was observed in the patients with grade 2 calcification. Only low-density lipoprotein cholesterol and lipoprotein (Lp)(a) were associated with the severity of CAVD. Regression analysis showed that age, Lp(a) and PCSK9 were independent predictors of CAVD. CONCLUSION: Data from this cross sectional study in a small sample of patients showed that plasma PCSK9 was correlated with the presence of CAVD but not its severity.


Asunto(s)
Estenosis de la Válvula Aórtica/metabolismo , Válvula Aórtica/patología , Calcinosis/metabolismo , Proproteína Convertasa 9/metabolismo , Anciano , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/metabolismo , Estenosis de la Válvula Aórtica/sangre , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Calcinosis/sangre , Calcinosis/diagnóstico por imagen , Estudios Transversales , Femenino , Humanos , Modelos Logísticos , Masculino , Estudios Prospectivos , Factores de Riesgo , Tomografía Computarizada por Rayos X
8.
Bioresour Technol ; 194: 334-43, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26210148

RESUMEN

Large-scale submerged fermentation (SmF) of Antrodia camphorata (A. camphorata) usually encounters challenges including tedious preparation of mycelial inoculum, long fermentation period (10-14 d), and poor repeatability. Here we developed an asexual reproduction-based repeated batch fermentation (RBF) process for bioactive metabolites production by A. camphorata ATCC 200183. Compared with traditional batch fermentation, production time was shortened to 58 d from 80 d (overall time for eight cycles) using the RBF process established in this study, and accordingly, the productivities of bioactive metabolites (including antrodins) were improved by 40-60%. Kinetic parameters (α is 2.1-18.7 times as ß) indicated that the cell growth was the major contribution for bioactive metabolites production. The RBF shows excellent batch-repeatability (Pearson correlation coefficient of 0.998±0.001), together with advantages of energy-efficient, low cost, and labor-saving, RBF process can be implemented to SmF by other filamentous fungi.


Asunto(s)
Antrodia/metabolismo , Medios de Cultivo/química , Fermentación , Reproducción Asexuada , Biomasa , Concentración de Iones de Hidrógeno , Cinética , Reproducibilidad de los Resultados , Triterpenos/química
9.
Appl Microbiol Biotechnol ; 99(18): 7639-49, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25947242

RESUMEN

Haloarchaea is an important group of polyhydroxyalkanoate (PHA)-accumulating organisms. However, few promising haloarchaeal species for economical and efficient PHA production have been reported. Here, we first discovered that Halogranum amylolyticum TNN58 could efficiently accumulate poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with a high 3-hydroxyvalerate (3HV) fraction using glucose as carbon source. Briefly, transmission electron microscopy (TEM) analysis revealed the presence of a large number of PHA granules in the cells. Gas chromatography-mass spectrometry (GC-MS) and proton nuclear magnetic resonance ((1)H NMR) analyses showed that PHAs synthesized from glucose was PHBV. Moreover, the 3HV content reached 20.1 mol%, which is the highest 3HV fraction thus far reported, as for PHBV produced by the wild-type strains grown on unrelated carbon courses. Fermentation experiments suggested that nitrogen-limited MG medium was better than nutrient-rich NOMG and AS168 medium for PHBV production. Additionally, glucose was the most suitable carbon source among the tested carbon sources. Interestingly, PHBV accumulation was almost paralleled by cell growth and glucose consumption. By applying the fed-batch process in fermentor, the PHBV production and cell dry weight were increased by approximately eight and four times, respectively, as compared with those of the batch process in shaking flasks. The classical PHA synthase genes were successfully cloned via consensus-degenerate hybrid oligonucleotide primers (CODEHOPs) and high-efficiency thermal asymmetric interlaced (hiTAIL) PCR methods. This finding suggested that H. amylolyticum shows promising potential in the low-cost biotechnological production of PHBV after further process optimization.


Asunto(s)
Euryarchaeota/metabolismo , Poliésteres/metabolismo , Carbono/metabolismo , Medios de Cultivo/química , Gránulos Citoplasmáticos/ultraestructura , Cromatografía de Gases y Espectrometría de Masas , Glucosa/metabolismo , Espectroscopía de Resonancia Magnética , Microscopía Electrónica de Transmisión , Poliésteres/química
10.
BMC Biotechnol ; 14: 107, 2014 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-25511290

RESUMEN

BACKGROUND: Xylanase can replace chemical additives to improve the volume and sensory properties of bread in the baking. Suitable baking xylanase with improved yield will promote the application of xylanase in baking industry. The xylanase XYNZG from the Plectosphaerella cucumerina has been previously characterized by heterologous expression in Pichia pastoris. However, P. pastoris is not a suitable host for xylanase to be used in the baking process since P. pastoris does not have GRAS (Generally Regarded As Safe) status and requires large methanol supplement during the fermentation in most conditions, which is not allowed to be used in the food industry. Kluyveromyces lactis, as another yeast expression host, has a GRAS status, which has been successfully used in food and feed applications. No previous work has been reported concerning the heterologous expression of xylanase gene xynZG in K. lactis with an aim for application in baking. RESULTS: The xylanase gene xynZG from the P. cucumerina was heterologously expressed in K. lactis. The recombinant protein XYNZG in K. lactis presented an approximately 19 kDa band on SDS-PAGE and zymograms analysis. Transformant with the highest halo on the plate containing the RBB-xylan (Remazol Brilliant Blue-xylan) was selected for the flask fermentation in different media. The results indicated that the highest activity of 115 U/ml at 72 h was obtained with the YLPU medium. The mass spectrometry analysis suggested that the hydrolytic products of xylan by XYNZG were mainly xylobiose and xylotriose. The results of baking trials indicated that the addition of XYNZG could reduce the kneading time of dough, increase the volume of bread, improve the texture, and have more positive effects on the sensory properties of bread. CONCLUSIONS: Xylanase XYNZG is successfully expressed in K. lactis, which exhibits the highest activity among the published reports of the xylanase expression in K. lactis. The recombinant XYNZG can be used to improve the volume and sensory properties of bread. Therefore, the expression yield of recombinant XYNZG can be further improved through engineered strain containing high copy numbers of the XYNZG, and optimized fermentation condition, making bread-baking application possible.


Asunto(s)
Ascomicetos/enzimología , Pan/análisis , Proteínas Fúngicas/metabolismo , Kluyveromyces/genética , Xilosidasas/metabolismo , Ascomicetos/genética , Culinaria , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Expresión Génica , Humanos , Kluyveromyces/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Gusto , Xilosidasas/química , Xilosidasas/genética
11.
J Integr Plant Biol ; 54(6): 412-21, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22583823

RESUMEN

AaNhaD, a gene isolated from the soda lake alkaliphile Alkalimonas amylolytica, encodes a Na(+) /H(+) antiporter crucial for the bacterium's resistance to salt/alkali stresses. However, it remains unknown whether this type of bacterial gene may be able to increase the tolerance of flowering plants to salt/alkali stresses. To investigate the use of extremophile genetic resources in higher plants, transgenic tobacco BY-2 cells and plants harboring AaNhaD were generated and their stress tolerance was evaluated. Ectopic expression of AaNhaD enhanced the salt tolerance of the transgenic BY-2 cells in a pH-dependent manner. Compared to wild-type controls, the transgenic cells exhibited increased Na(+) concentrations and pH levels in the vacuoles. Subcellular localization analysis indicated that AaNhaD-GFP fusion proteins were primarily localized in the tonoplasts. Similar to the transgenic BY-2 cells, AaNhaD-overexpressing tobacco plants displayed enhanced stress tolerance when grown in saline-alkali soil. These results indicate that AaNhaD functions as a pH-dependent tonoplast Na(+) /H(+) antiporter in plant cells, thus presenting a new avenue for the genetic improvement of salinity/alkalinity tolerance.


Asunto(s)
Gammaproteobacteria/genética , Plantas Modificadas Genéticamente/metabolismo , Tolerancia a la Sal/genética , Intercambiadores de Sodio-Hidrógeno/genética , Sodio/metabolismo , Línea Celular , Citosol/metabolismo , Concentración de Iones de Hidrógeno , Intercambiadores de Sodio-Hidrógeno/metabolismo , Nicotiana/metabolismo , Vacuolas/metabolismo
12.
Microb Ecol ; 62(3): 599-608, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21611687

RESUMEN

The method of continuous thermophilic composting (CTC) remarkably shortened the active composting cycle and enhanced the compost stability. Effects of CTC on the quantities of bacteria, with a comparison to the traditional composting (TC) method, were explored by plate count with incubation at 30, 40 and 50°C, respectively, and by quantitative PCR targeting the universal bacterial 16S rRNA genes and the Bacillus 16S rRNA genes. The comparison of cultivatable or uncultivatable bacterial numbers indicated that CTC might have increased the biomass of bacteria, especially Bacillus spp., during the composting. Denaturing gradient gel electrophoresis (DGGE) analysis was employed to investigate the effects of CTC on bacterial diversity, and a community dominated by fewer species was detected in a typical CTC run. The analysis of sequence and phylogeny based on DGGE indicated that the continuously high temperature had changed the structure of bacterial community and strengthened the mainstay role of the thermophilic and spore-forming Bacillus spp. in CTC run.


Asunto(s)
Bacillus/crecimiento & desarrollo , Calor , Eliminación de Residuos/métodos , Microbiología del Suelo , Suelo , Bacillus/genética , Biomasa , Recuento de Colonia Microbiana , ADN Bacteriano/genética , Electroforesis en Gel de Gradiente Desnaturalizante , Filogenia , ARN Ribosómico 16S/genética
13.
Bioresour Technol ; 102(2): 1383-8, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20934325

RESUMEN

Actinomycetes degrade cellulose and solubilize lignin during composting. Changes in the diversity of the actinomycetal communities and the 16S rDNA copy numbers of actinomycetes were monitored by denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR), respectively, during continuous thermophilic composting (CTC) and traditional composting (TC). qPCR indicated that the copy numbers from the CTC samples were 25-80% higher than those from the TC samples during similar phases of active composting and they were lower than 3×10(9) gene copies/g (dry weight) in the mature compost from both runs. DGGE showed a more diverse actinomycetal community in the CTC than in TC, averaging 16 bands as compared to 12 bands, at the post peak temperature phase. The study suggested that temperatures higher than 50 °C in CTC benefited the growth of actinomycetes.


Asunto(s)
Actinobacteria/crecimiento & desarrollo , Actinobacteria/genética , Electroforesis en Gel de Gradiente Desnaturalizante/métodos , Reacción en Cadena de la Polimerasa/métodos , Microbiología del Suelo , Suelo , Temperatura , Genes Bacterianos/genética , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética
14.
Wei Sheng Wu Xue Bao ; 47(4): 634-8, 2007 Aug.
Artículo en Chino | MEDLINE | ID: mdl-17944363

RESUMEN

In the previous study we have isolated DNA fragment containing an alanine racemase gene (dadX) from Pseudomonas fluorescens TM5-2. Adjacent to dadX one ORF similar to a putative glycine/D-amino acid oxidase gene have been found. The same gene organization is found in several Pseudomonas species. Here, author would characterize this ORF to determine what kind of enzyme this gene encodes. DNA fragment containing gene encoding putative glycine/D-amino acid oxidase was cloned into the expression vector. Firstly oxidase activity in cell lysates prepared from the recombinant cells was measured, however, neither glycine nor D-alanine were oxidized judging from hydrogen peroxide formation. Secondly when the amino acid sequence deduced from the oxidase gene was compared to dye-linked D-amino acid dehydrogenases, all the important residues including FAD-binding motif were conserved. This gene was transformed and checked on TFC plate, it showed some activities of D-amino acid dehydrogenase. D-amino acid dehydrogenase activity was also detected when D-alanine and DCIP were used. The best substrate of this enzyme is D-histdine, which is different from some reports. Author will be in progress to purify the dehydrogenase and determine enzyme characteristics.


Asunto(s)
Proteínas Bacterianas/genética , D-Aminoácido Oxidasa/genética , Expresión Génica , Pseudomonas fluorescens/enzimología , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , D-Aminoácido Oxidasa/química , D-Aminoácido Oxidasa/metabolismo , Datos de Secuencia Molecular , Pseudomonas fluorescens/química , Pseudomonas fluorescens/genética , Alineación de Secuencia , Especificidad por Sustrato
15.
Huan Jing Ke Xue ; 28(5): 1095-101, 2007 May.
Artículo en Chino | MEDLINE | ID: mdl-17633185

RESUMEN

For studying the bacterial diversity and the mechanism of denitrification in sequencing bath biofilm reactor (SBBR) treating landfill leachate to provide microbial evidence for technique improvements, total microbial DNA was extracted from samples which were collected from natural landfill leachate and biofilm of a SBBR that could efficiently remove NH4+ -N and COD of high concentration. 16S rDNA fragments were amplified from the total DNA successfully using a pair of universal bacterial 16S rDNA primer, GC341F and 907R, and then were used for denaturing gradient gel electrophoresis (DGGE) analysis. The bands in the gel were analyzed by statistical methods and excided from the gel for sequencing, and the sequences were used for homology analysis and then two phylogenetic trees were constructed using DNAStar software. Results indicated that the bacterial diversity of the biofilm in SBBR and the landfill leachate was abundant, and no obvious change of community structure happened during running in the biofilm, in which most bacteria came from the landfill leachate. There may be three different modes of denitrification in the reactor because several different nitrifying bacteria, denitrifying bacteria and anaerobic ammonia oxidation bacteria coexisted in it. The results provided some valuable references for studying microbiological mechanism of denitrification in SBBR.


Asunto(s)
Bacterias/crecimiento & desarrollo , Biopelículas , Reactores Biológicos/microbiología , Aguas del Alcantarillado/microbiología , Eliminación de Residuos Líquidos/métodos , Bacterias/clasificación , Bacterias/genética , Biodiversidad , Electroforesis en Gel de Agar/métodos , Microbiología Ambiental , Variación Genética , Filogenia , Reacción en Cadena de la Polimerasa/métodos , ARN Ribosómico 16S/genética
16.
Wei Sheng Wu Xue Bao ; 47(2): 290-4, 2007 Apr.
Artículo en Chino | MEDLINE | ID: mdl-17552237

RESUMEN

Recent investigations on the microbial ecology of oil reservoirs in a variety of locales indicated that these habitats harbor various assemblages. In this study, a cultured-independent molecular technique, Terminal Restriction Fragment Length Polymorphism (T-RFLP), was used to analyze the microbial diversity of an injection well (S12-ZHU) and three related production wells (S12-4, S12-5 and S12-19) in the ShengLi oilfield (Shandong province, China). The 16S rRNA genes were amplified by PCR with the 5'carboxy-fluorescein (5-FAM)-labelled universal forward primers (27F for bacteria and 21F for archaea) and a universal reverse primer (1495R). Then the 16S rRNA genes were digested with restriction enzymes (Hae III and Hha I) and analyzed by using an automated DNA sequencer. The Shannon-Wiener Diversity index, based on the T-RFLP profiles, indicated that the bacterial and archaeal species richness in the injection well was higher than those of the production ones. The similarity coefficient showed the microbial community similarity among the four samples was 22.4%-30.8% (Bacteria) and 20.8%-34.5% (Archaea), respectively. According to the analysis by TAP T-RFLP program, species belonging to Pseudomonas, Marinobacter and Methanosarcina as well as some uncultured archaeon were supposed to be the dominant bacteria in all four samples. Thus, this study indicates that T-RFLP is useful for analysis of the microbial diversity in petroleum reservoirs.


Asunto(s)
Bacterias/clasificación , Ecología , Petróleo/microbiología , Polimorfismo de Longitud del Fragmento de Restricción , Bacterias/genética , ARN Ribosómico 16S/genética
17.
J Basic Microbiol ; 47(2): 132-7, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17440915

RESUMEN

The chaperonin molecular machine from hyperthermophilic archaeon Pyrococcus furiosus was studied in this paper. The Pyrococcus furiosus chaperonin gene (PfCPN) was amplified by PCR from the Pyrococcus furiosus genomic DNA, and expressed in Escherichia coli BL21-Codonplus(DE)(3)-RIL. The recombinant PfCPN was purified to homogeneity by using ion-exchange and size-exclusion chromatography. It was found that the ATPase activity of the PfCPN was highest at 88 degrees C, and there existed a nested cooperativity of the ATPase activity of the PfCPN. This result suggested that nested allosteric behavior may be common to chaperonin molecular machines from archaea. The half-life (t(1/2)) of the ATPase activity of the PfCPN at 100 degrees C was about 60 min. The PfCPN displayed chaperone activity in preventing lysozyme from thermal inactivation. This chaperone activity was in an ATP-dependent manner.


Asunto(s)
Proteínas Arqueales/genética , Chaperoninas/genética , Chaperoninas/metabolismo , Pyrococcus furiosus/química , Adenosina Trifosfatasas/química , Adenosina Trifosfatasas/genética , Adenosina Trifosfatasas/metabolismo , Chaperoninas/química , Chaperoninas/aislamiento & purificación , Clonación Molecular , Escherichia coli/genética , Muramidasa/química , Muramidasa/metabolismo , Reacción en Cadena de la Polimerasa , Pyrococcus furiosus/genética , Pyrococcus furiosus/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Temperatura
18.
Appl Microbiol Biotechnol ; 75(5): 1015-22, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17361429

RESUMEN

In this work, a 2(2) factorial design was employed combining with response surface methodology (RSM) to optimize the medium compositions for the production of alkaline beta-mannanase by alkaliphilic Bacillus sp. N16-5 isolated previously from sediment of Wudunur Soda Lake in Inner Mongolia, China. The central composite design (CCD) used for the analysis of treatment combinations showed that a second-order polynomial regression model was in good agreement with experimental results, with R (2) = 0.9829 (P < 0.05). The maximum activity was obtained at NaCl concentration (84.4 g l(-1)) and sodium glutamate (3.11 g l(-1)) and a high medium pH around 10.0. Under such conditions, the activity of alkaline beta-mannanase achieved 310.1 U/ml in the scale of 5-l fermenter, which was increased nearly twice compared with the original. Through optimization, the substrates shifted from the expensive substrates, such as locust bean gum and peptone, to the inexpensive ones such as konjac powder, soymeal, and sodium glutamate. The experiment results also suggested that the environmental conditions of high salinity and high alkalinity, as well as the inducer substrates, play very important roles in the production of the alkaline beta-mannanase by alkaliphilic Bacillus sp. N16-5.


Asunto(s)
Bacillus/enzimología , Medios de Cultivo , beta-Manosidasa/biosíntesis , Técnicas de Cultivo de Célula
19.
Wei Sheng Wu Xue Bao ; 46(2): 243-8, 2006 Apr.
Artículo en Chino | MEDLINE | ID: mdl-16736585

RESUMEN

According to analysis of proteomic profiling for Thermoanaerobacter tencongensis, TTE0090 could be a novel gene of glucokianse (GLK), though no GLK gene was annotated in the genomic data. With the methods of cloning and expression in vitro, the recombinant TTE0090 was successfully expressed and purified. The recombinant TTE0090 exhibited the catalysis of GLK, even at high temperatures. Detection of expression levels and catalysis of TTE0090 in vivo was furthermore carried out at different temperatures. The expression of TTE0090 was attenuated during the culture temperature elevated; however, the specific activity was positively correlated to temperature raised. This leads a possibility that the metabolic capacity of glycolysis in T. tencongensis is relatively constant at different temperatures. All the results herein demonstrate that TTE0090 is a novel gene of GLK. The studies on TTE0090 and its protein product, thus, may deepen our understanding of the adaptation mechanism of thermophilic bacteria living in harsh environment.


Asunto(s)
Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Expresión Génica , Glucoquinasa/química , Glucoquinasa/genética , Thermoanaerobacter/enzimología , Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Catálisis , Estabilidad de Enzimas , Escherichia coli/genética , Escherichia coli/metabolismo , Glucoquinasa/aislamiento & purificación , Glucoquinasa/metabolismo , Cinética , Temperatura , Thermoanaerobacter/química
20.
Wei Sheng Wu Xue Bao ; 46(2): 249-54, 2006 Apr.
Artículo en Chino | MEDLINE | ID: mdl-16736586

RESUMEN

The enzyme of 6-phosphofructokinase (PFK) is a key element in glycolysis, widely distributed in most eukaryote and prokaryote. Although the gene TTE1816 from Thermoanaerobacter tengcongenisis was annotated as a PFK based upon genomic analysis, its catalytic properties have to be examined experimentally. The cells of T. tengcongenisis were cultured at optimal temperature followed by the separation of the bacterial proteins with two-dimensional electrophoresis (2-DE). These 2-DE spots located around the theoretical values of pI and MW for TTE1816 were picked up and identified by mass spectrometry, suggesting that TTE1816 indeed expressed at such high temperature. Furthermore, TTE1816 was cloned into an expression vector and expressed soluble protein in E. coli BL-21 strain. The kinetic data revealed that the recombinant TTE1816 exhibited the catalysis to phosphorylate fructose-6-phosphate (F-6-P). Not only converting F-6-P to F-1,6-BP, does TTE1816 also catalyze the phosphorylation of glucose, fructose, mannose and glucose-6-phosphate(G-6-P) with optimal temperature at 60 degrees C . Interestingly, TTE1816 is capable to catalyze the reverse reaction as a bisphosphatase for dephosphorylation of F-1,6-BP under the reaction conditions with high concentrations of enzyme as well as substrates. The data reported herein demonstrate that a new member of PFK family has been identified in T. tengcongenisis.


Asunto(s)
Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Clonación Molecular , Expresión Génica , Fosfofructoquinasa-1/química , Fosfofructoquinasa-1/genética , Thermoanaerobacter/enzimología , Proteínas Bacterianas/metabolismo , Estabilidad de Enzimas , Escherichia coli/genética , Escherichia coli/metabolismo , Cinética , Fosfofructoquinasa-1/metabolismo , Especificidad por Sustrato , Thermoanaerobacter/química
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