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1.
Brain Sci ; 14(7)2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39061476

RESUMEN

Self-ambivalence, a prevalent phenomenon in daily life, has been increasingly substantiated by research. It refers to conflicting self-views and evaluations, primarily concerning self-worth and morality. Previous behavioral research has distinguished self-worth and moral ambivalence, but it remains unclear whether they have separable neural bases. The present study addressed this question by examining resting-state brain activity (i.e., the fractional amplitude of low-frequency fluctuations, fALFF) and connectivity (i.e., resting-state functional connectivity, RSFC) in 112 college students. The results found that self-worth ambivalence was positively related to the fALFF in the orbitofrontal cortex (OFC) and left superior parietal lobule (SPL). The RSFC strength between the SPL and precuneus/posterior cingulate cortex (PCC) was positively related to self-worth ambivalence. Moral ambivalence was positively associated with the fALFF in the left SPL (extending into the temporoparietal junction) and right SPL. The RSFC strengths between the left SPL/TPJ and OFC, as well as the RSFC strengths between the right SPL as a seed and the bilateral middle and inferior temporal gyrus, were associated with moral ambivalence. Overall, the neural bases of self-worth and moral ambivalence are associated with the SPL and OFC, involved in attentional alertness and value representation, respectively. Additionally, the neural basis of moral ambivalence is associated with the TPJ, responsible for mentalizing.

2.
BMC Ecol Evol ; 21(1): 114, 2021 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-34098879

RESUMEN

BACKGROUND: As flatfish, turbot undergo metamorphosis as part of their life cycle. In the larval stage, turbot live at the ocean surface, but after metamorphosis they move to deeper water and turn to benthic life. Thus, the light environment differs greatly between life stages. The visual system plays a great role in organic evolution, but reports of the relationship between the visual system and benthic life are rare. In this study, we reported the molecular and evolutionary analysis of opsin genes in turbot, and the heterochronic shifts in opsin expression during development. RESULTS: Our gene synteny analysis showed that subtype RH2C was not on the same gene cluster as the other four green-sensitive opsin genes (RH2) in turbot. It was translocated to chromosome 8 from chromosome 6. Based on branch-site test and spectral tuning sites analyses, E122Q and M207L substitutions in RH2C, which were found to be under positive selection, are closely related to the blue shift of optimum light sensitivities. And real-time PCR results indicated the dominant opsin gene shifted from red-sensitive (LWS) to RH2B1 during turbot development, which may lead to spectral sensitivity shifts to shorter wavelengths. CONCLUSIONS: This is the first report that RH2C may be an important subtype of green opsin gene that was retained by turbot and possibly other flatfish species during evolution. Moreover, E122Q and M207L substitutions in RH2C may contribute to the survival of turbot in the bluish colored ocean. And heterochronic shifts in opsin expression may be an important strategy for turbot to adapt to benthic life.


Asunto(s)
Evolución Biológica , Peces Planos , Opsinas , Animales , Proteínas de Peces/genética , Peces Planos/genética , Opsinas/genética , Filogenia , Selección Genética , Sintenía
3.
Theriogenology ; 166: 83-89, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33711650

RESUMEN

Sebastes schlegelii is a typical viviparous teleost with six months sperm storage duration from November to April. In this study, spermatozoa morphological and physiological characteristics and sperm location in the female ovary were investigated by electron microscopy, computer-assisted sperm analyzer and histologic analysis, respectively. During copulation, we observed that spermatozoa in the testis had mature structure with rod-shaped head, a short midpiece, and a long flagellum. And further verified sperm swam freely at a high speed in the ovary fluid. After copulation, we only found swimming sperm in the ovary fluid at the early storage stage (November to December) and the majority of sperm were scattered randomly in the ovary cavity and partially concentrated in the crypt between the oocyte and stalk of follicle. Thereafter, the ovarian epithelium around the oocytes proliferated rapidly and wrapping spermatozoa outside of the follicular layer and formed a lot of crypts outside of the follicular layer which served as the sperm storage site until fertilization. The present findings would be useful for further understanding the mechanism of long-term sperm storage in viviparous teleost.


Asunto(s)
Perciformes , Maduración del Esperma , Animales , Copulación , Femenino , Masculino , Ovario , Espermatozoides
4.
Ecotoxicol Environ Saf ; 208: 111617, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33396137

RESUMEN

Nitrate (NO3-), a potential toxic nitrogenous compound to aquatic animals, is distributed in aquatic ecosystems worldwide. The aim of this study was to investigate the effects of different NO3- levels on growth performance, health status, and endocrine function of juvenile turbot (Scophthalmus maximus) in recirculating aquaculture systems (RAS). Fish were exposed to 0 mg/L (control, CK), 50 mg/L (low nitrate, LN), 200 mg/L (medium nitrate, MN), and 400 mg/L (high nitrate, HN) NO3-N for 60 d in experimental RAS. Cumulative survival (CS) was significantly decreased with increasing NO3- levels in LN, MN, and HN. The lowest CS was 35% in the HN group. Growth parameters, including absolute growth rate, specific growth rate, and feed conversion rate, were significantly different in HN compared with that in the CK. Histological survey of gills and liver revealed dose-dependent histopathological damage induced by NO3- exposure and significant differences in glutamate pyruvate transaminase and glutamate oxalate transaminase in MN and HN compared with that in the CK. The hepatosomatic index in HN was significantly higher than that in the CK. Additionally, NO3- significantly increased bioaccumulation in plasma in LN, MN, and HN compared to that in the CK. Significant decreases in hemoglobin and increases in methemoglobin levels indicated reduced oxygen-carrying capacity in HN. Additionally, qRT-PCR and enzyme-linked immunosorbent assay (ELISA) were developed to investigate key biomarkers involved in the GH/IGF-1, HPT, and HPI axes. Compared with that in the CK, the abundance of GH, GHRb, and IGF-1 was significantly lower in HN, whereas GHRa did not differ between treatments. The plasma T3 level significantly decreased in LN, MN, and HN and T4 significantly decreased in HN. The CRH, ACTH, and plasma cortisol levels were significantly upregulated in HN compared with that in the CK. We conclude that elevated NO3- exposure leads to growth retardation, impaired health status, and endocrine disorders in turbot and the NO3- level for juvenile turbot culture should not exceed 50 mg/L NO3-N in RAS. Our findings indicate that endocrine dysfunction of the GH/IGF-1, HPT, and HPI axes might be responsible for growth inhibition induced by NO3- exposure.


Asunto(s)
Acuicultura/métodos , Sistema Endocrino/efectos de los fármacos , Peces Planos/crecimiento & desarrollo , Nitratos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Ecosistema , Sistema Endocrino/metabolismo , Branquias/efectos de los fármacos , Branquias/patología , Estado de Salud , Hígado/efectos de los fármacos , Hígado/patología , Alimentos Marinos , Hormonas Tiroideas/metabolismo
5.
Front Cell Dev Biol ; 8: 575788, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33330452

RESUMEN

Germ cells play a key role in gonad development. As precursors, primordial germ cells (PGCs) are particularly important for germline formation. However, the origination and migration patterns of PGCs are poorly studied in marine fish, especially for viviparous economic species. The vasa gene has been widely used as a germ cell marker to identify a germline because vasa RNA is a component of germ plasm. In this study, we described the expression pattern of black rockfish (Sebastes schlegelii) vasa (Ssvas) in gonadal formation and development by in situ hybridization. The results showed that Ssvas failed in localization at the cleavage furrows until the late gastrula stage, when PGCs appeared and migrated to the genital ridge and formed elongated gonadal primordia at 10 days after birth. This study firstly revealed the PGCs origination and migration characteristics in viviparous marine fish. Furthermore, we microinjected chimeric mRNA containing EGFP and the 3'untranslated region (3'UTR) of Ssvas into zebrafish (Danio rerio) and marine medaka (Oryzias melastigma) fertilized eggs for tracing PGCs. We found that, although Sebastes schlegelii lacked early localization, similar to red seabream (Pagrus major) and marine medaka, only the 3'UTR of Ssvas vasa 3'UTR of black rockfish was able to label both zebrafish and marine medaka PGCs. In comparison with other three Euteleostei species, besides some basal motifs, black rockfish had three specific motifs of M10, M12, and M19 just presented in zebrafish, which might play an important role in labeling zebrafish PGCs. These results will promote germ cell manipulation technology development and facilitate artificial reproduction regulation in aquaculture.

6.
DNA Res ; 26(6): 453-464, 2019 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-31711192

RESUMEN

Black rockfish (Sebastes schlegelii) is an economically important viviparous marine teleost in Japan, Korea, and China. It is characterized by internal fertilization, long-term sperm storage in the female ovary, and a high abortion rate. For better understanding the mechanism of fertilization and gestation, it is essential to establish a reference genome for viviparous teleosts. Herein, we used a combination of Pacific Biosciences sequel, Illumina sequencing platforms, 10× Genomics, and Hi-C technology to obtain a genome assembly size of 848.31 Mb comprising 24 chromosomes, and contig and scaffold N50 lengths of 2.96 and 35.63 Mb, respectively. We predicted 39.98% repetitive elements, and 26,979 protein-coding genes. S. schlegelii diverged from Gasterosteus aculeatus ∼32.1-56.8 million years ago. Furthermore, sperm remained viable within the ovary for up to 6 months. The glucose transporter SLC2 showed significantly positive genomic selection, and carbohydrate metabolism-related KEGG pathways were significantly up-regulated in ovaries after copulation. In vitro suppression of glycolysis with sodium iodoacetate reduced sperm longevity significantly. The results indicated the importance of carbohydrates in maintaining sperm survivability. Decoding the S. schlegelii genome not only provides new insights into sperm storage; additionally, it is highly valuable for marine researchers and reproduction biologists.


Asunto(s)
Fertilización , Genómica/métodos , Ovario/metabolismo , Perciformes/genética , Espermatozoides/metabolismo , Secuenciación Completa del Genoma/métodos , Animales , Metabolismo de los Hidratos de Carbono/genética , Supervivencia Celular/genética , Femenino , Proteínas Facilitadoras del Transporte de la Glucosa/genética , Glucólisis/genética , Masculino , Ovario/citología , Espermatozoides/citología , Viviparidad de Animales no Mamíferos/genética
7.
Int J Mol Sci ; 20(14)2019 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-31336592

RESUMEN

Human immunodeficiency virus type-1 and hepatitis C virus (HIV/HCV) coinfection occurs when a patient is simultaneously infected with both human immunodeficiency virus type-1 (HIV-1) and hepatitis C virus (HCV), which is common today in certain populations. However, the treatment of coinfection is a challenge because of the special considerations needed to ensure hepatic safety and avoid drug-drug interactions. Multitarget inhibitors with less toxicity may provide a promising therapeutic strategy for HIV/HCV coinfection. However, the identification of one molecule that acts on multiple targets simultaneously by experimental evaluation is costly and time-consuming. In silico target prediction tools provide more opportunities for the development of multitarget inhibitors. In this study, by combining Naïve Bayes (NB) and support vector machine (SVM) algorithms with two types of molecular fingerprints, MACCS and extended connectivity fingerprints 6 (ECFP6), 60 classification models were constructed to predict compounds that were active against 11 HIV-1 targets and four HCV targets based on a multiple quantitative structure-activity relationships (multiple QSAR) method. Five-fold cross-validation and test set validation were performed to measure the performance of the 60 classification models. Our results show that the 60 multiple QSAR models appeared to have high classification accuracy in terms of the area under the ROC curve (AUC) values, which ranged from 0.83 to 1 with a mean value of 0.97 for the HIV-1 models and from 0.84 to 1 with a mean value of 0.96 for the HCV models. Furthermore, the 60 models were used to comprehensively predict the potential targets of an additional 46 compounds, including 27 approved HIV-1 drugs, 10 approved HCV drugs and nine selected compounds known to be active against one or more targets of HIV-1 or HCV. Finally, 20 hits, including seven approved HIV-1 drugs, four approved HCV drugs, and nine other compounds, were predicted to be HIV/HCV coinfection multitarget inhibitors. The reported bioactivity data confirmed that seven out of nine compounds actually interacted with HIV-1 and HCV targets simultaneously with diverse binding affinities. The remaining predicted hits and chemical-protein interaction pairs with the potential ability to suppress HIV/HCV coinfection are worthy of further experimental investigation. This investigation shows that the multiple QSAR method is useful in predicting chemical-protein interactions for the discovery of multitarget inhibitors and provides a unique strategy for the treatment of HIV/HCV coinfection.


Asunto(s)
Fármacos Anti-VIH/química , Fármacos Anti-VIH/farmacología , Antivirales/química , Antivirales/farmacología , Aprendizaje Automático , Relación Estructura-Actividad Cuantitativa , Algoritmos , Teorema de Bayes , Bases de Datos Farmacéuticas , Descubrimiento de Drogas , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , Hepacivirus/efectos de los fármacos , Hepatitis C/tratamiento farmacológico , Hepatitis C/virología , Humanos , Modelos Moleculares , Conformación Molecular , Estructura Molecular , Polifarmacología , Unión Proteica
8.
J Cheminform ; 11(1): 47, 2019 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-31292807

RESUMEN

To better leverage the accumulated bioactivity data in the ChEMBL database, we have developed Bioactivity-explorer, a web application for interactive visualization and exploration of the large-scale bioactivity data in ChEMBL. Mining and integration of the Therapeutic Target Database disease-target mapping into the ChEMBL database has enabled Bioactivity-explorer to include 493,430 scaffolds, 31,400,000 matched molecular pairs, 1330,220 target-target interactions in terms of shared active compounds, 4526,718 target-target interactions in terms of shared active scaffolds, 97,041,700 molecule-molecule interactions and 14,974 disease-target mappings. This web tool is available at http://cadd.pharmacy.nankai.edu.cn/b17r . The source codes of the front end and back end, released under MIT license, can be found at GitHub.

9.
Comput Struct Biotechnol J ; 16: 600-610, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30546860

RESUMEN

Traditional Chinese Medicine (TCM) has a long history of widespread clinical applications, especially in East Asia, and is becoming frequently used in Western countries. However, owing to extreme complicacy in both chemical ingredients and mechanism of action, a deep understanding of TCM is still difficult. To accelerate the modernization and popularization of TCM, a single comprehensive database is required, containing a wealth of TCM-related information and equipped with complete analytical tools. Here we present YaTCM (Yet another Traditional Chinese Medicine database), a free web-based toolkit, which provides comprehensive TCM information and is furnished with analysis tools. YaTCM allows a user to (1) identify the potential ingredients that are crucial to TCM herbs through similarity search and substructure search, (2) investigate the mechanism of action for TCM or prescription through pathway analysis and network pharmacology analysis, (3) predict potential targets for TCM molecules by multi-voting chemical similarity ensemble approach, and (4) explore functionally similar herb pairs. All these functions can lead to one systematic network for visualization of TCM recipes, herbs, ingredients, definite or putative protein targets, pathways, and diseases. This web service would help in uncovering the mechanism of action of TCM, revealing the essence of TCM theory and then promoting the drug discovery process. YaTCM is freely available at http://cadd.pharmacy.nankai.edu.cn/yatcm/home.

10.
Database (Oxford) ; 20182018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30371760

RESUMEN

Glaucoma is a group of neurodegenerative diseases that can cause irreversible blindness. The current medications, which mainly reduce intraocular pressure to slow the progression of disease, may have local and systemic side effects. Recently, medications with possible neuroprotective effects have attracted much attention. To assist in the identification of new glaucoma drugs, we created a glaucomatous chemogenomics database (GCDB; http://cadd.pharmacy.nankai.edu.cn/gcdb/home) in which various glaucoma-related chemogenomics data records are assembled, including 275 genes, 105 proteins, 83 approved or clinical trial drugs, 90 206 chemicals associated with 213 093 records of reported bioactivities from 22 324 corresponding bioassays and 5630 references. Moreover, an improved chemical similarity ensemble approach computational algorithm was incorporated in the GCDB to identify new targets and design new drugs. Further, we demonstrated the application of GCDB in a case study screening two chemical libraries, Maybridge and Specs, to identify interactions between small molecules and glaucoma-related proteins. Finally, six and four compounds were selected from the final hits for in vitro human glucocorticoid receptor (hGR) and adenosine A3 receptor (A3AR) inhibitory assays, respectively. Of these compounds, six were shown to have inhibitory activities against hGR, with IC50 values ranging from 2.92-28.43 µM, whereas one compoundshowed inhibitory activity against A3AR, with an IC50 of 6.15 µM. Overall, GCDB will be helpful in target identification and glaucoma chemogenomics data exchange and sharing, and facilitate drug discovery for glaucoma treatment.


Asunto(s)
Simulación por Computador , Bases de Datos Genéticas , Descubrimiento de Drogas , Genómica , Glaucoma/tratamiento farmacológico , Glaucoma/genética , Secuencia de Bases , Humanos , Ligandos , Simulación del Acoplamiento Molecular , Interfaz Usuario-Computador
11.
Dalton Trans ; 47(20): 6934-6941, 2018 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-29713709

RESUMEN

Although intensive studies have been conducted on layered transition metal oxide(TMO)-based cathode materials and metal oxide-based anode materials for Li-ion batteries, their precursors generally follow different or even complex synthesis routes. To share one route for preparing precursors of the cathode and anode materials, herein, we demonstrate a facile co-precipitation method to fabricate Ni-rich hydroxide precursors of Ni0.8Co0.1Mn0.1(OH)2. Ni-rich layered oxide of LiNi0.8Co0.1Mn0.1O2 is obtained by lithiation of the precursor in air. An NiO-based anode material is prepared by calcining the precursor or multi-walled carbon nanotubes (MWCNTs) incorporated precursors. The pre-addition of ammonia solution can simplify the co-precipitation procedures and the use of an air atmosphere can also make the heat treatment facile. LiNi0.8Co0.1Mn0.1O2 as the cathode material delivers a reversible capacity of 194 mA h g-1 at 40 mA g-1 and a notable cycling retention of 88.8% after 100 cycles at 200 mA g-1. This noticeable performance of the cathode arises from a decent particle morphology and high crystallinity of the layered oxides. As the anode material, the MWCNTs-incorporated oxides deliver a much higher reversible capacity of 811.1 mA h g-1 after 200 cycles compared to the pristine oxides without MWCNTs. The improvement on electrochemical performance can be attributed to synergistic effects from MWCNTs incorporation, including reinforced electronic conductivity, rich meso-pores and an alleviated volume effect. This facile and sharing method may offer an integrated and economical approach for commercial production of Ni-rich electrode materials for Li-ion batteries.

12.
Sci Rep ; 7(1): 1960, 2017 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-28512342

RESUMEN

Air quality around the globe is declining and public health is seriously threatened by indoor air pollution. Typically, indoor air pollutants are composed of a series of volatile organic compounds (VOCs) that are generally harmful to the human body, especially VOCs with low molecular weights (less than 100 Da). Moreover, in some situations, more than one type of VOC is present; thus, a device that can detect one or more VOCs simultaneously would be most beneficial. Here, we synthesized a sensor array with 4 units to detect 4 VOCs: acetone (unit 1), benzene (unit 2), methanol (unit 3) and formaldehyde (unit 4) simultaneously. All units were simultaneously exposed to 2.5 ppm of all four VOCs. The sensitivity of unit 1 was 14.67 for acetone and less than 2.54 for the other VOCs. The sensitivities of units 2, 3 and 4 to benzene, methanol and formaldehyde were 2 18.64, 20.98 and 17.26, respectively, and less than 4.01 for the other VOCs. These results indicated that the sensor array exhibited good selectivity and could be used for the real-time monitoring of indoor air quality. Thus, this device will be useful in situations requiring the simultaneous detection of multiple VOCs.

13.
Rev Sci Instrum ; 85(10): 103506, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25362392

RESUMEN

Neutron emission measurement at the HL-2A tokamak device with a liquid scintillation detector is described. The detector was placed at a location with little structure material in the field of view, and equipped with a gain monitoring system which could provide the possibility to evaluate the gain variation as well as to correct for the detector response. Time trace of the neutron emissivity was obtained and it was consistent with the result of a standard (235)U fission chamber. During the plasma discharge the neutron yield could vary by about four orders of magnitude and the fluctuation of the detector gain was up to about 6%. Pulse height spectrum of the liquid scintillation detector was constructed and corrected with the aid of the gain monitoring system, and the correction was found to be essential for the assessment of the neutron energy spectrum. This successful measurement offered experience and confidence for the application of liquid scintillation detectors in the upcoming neutron camera system.

14.
Bioresour Technol ; 135: 254-61, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23305897

RESUMEN

Sulfuric acid treated corn fiber hydrolysate (SACFH) inhibited cell growth and the production of butanol (4.7±0.2 g/L) by Clostridium beijerinckii IB4 in P2 medium. Optimal medium components were determined using fractional factorial design. NH4HCO3, FeSO4·7H2O and CaCO3 were demonstrated to be significant components in the production of butanol. The Box-Behnken design and a corresponding quadratic model were used to predict medium components (NH4HCO3 1.96 g/L, FeSO4·7H2O 0.26 g/L and CaCO3 3.15 g/L) and butanol yield (9.5 g/L). The confirmation experiment, under the predicted optimal conditions, yielded a butanol level of 9.5±0.1g/L. This study indicates that the Box-Behnken design is an effective approach for screening the optimal medium components required for the production of butanol. It also demonstrates that SACFH, which has high levels of inhibitors such as furan and phenolic compounds, may be used as a renewable carbon source in the production of biofuels.


Asunto(s)
Butanoles/metabolismo , Clostridium beijerinckii/genética , Mutación/genética , Ácidos Sulfúricos/farmacología , Zea mays/metabolismo , Análisis de Varianza , Carbono/farmacología , Clostridium beijerinckii/efectos de los fármacos , Medios de Cultivo/farmacología , Hidrólisis/efectos de los fármacos , Reproducibilidad de los Resultados , Zea mays/efectos de los fármacos
15.
Bioresour Technol ; 135: 379-85, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-22985825

RESUMEN

A Clostridium beijerinckii mutant RT66 with considerable inhibitor-tolerance obtained by continuous culture was used for butanol production from non-detoxified hemicellulosic hydrolysate of corn fiber treated with dilute sulfuric acid (SAHHC). In fed-batch fermentation, 1.8L of diluted SAHHC containing 10 g/L of reducing sugar was provided during the acidogenic phase and 0.2L of concentrated SAHHC containing 300 g/L of reducing sugar was provided during the solventogenic phase. The mutant produced a total amount of solvents of 12.9 g/L, which consisted of 3.1 g/L of acetone, 9.3 g/L of butanol and 0.5 g/L of ethanol. A solvent yield of 0.35 g/g sugar and a productivity of 0.18 g/L h in 72 h were achieved. The remarkable inhibitor-tolerance of C. beijerinckii RT66 demonstrates that this may be an excellent strain for butanol production from ligocellulosic materials.


Asunto(s)
Adaptación Fisiológica/efectos de los fármacos , Butanoles/metabolismo , Clostridium beijerinckii/metabolismo , Mutación/genética , Fenoles/toxicidad , Polisacáridos/metabolismo , Zea mays/metabolismo , Técnicas de Cultivo Celular por Lotes , Clostridium beijerinckii/efectos de los fármacos , Clostridium beijerinckii/genética , Clostridium beijerinckii/aislamiento & purificación , Medios de Cultivo/farmacología , Fermentación/efectos de los fármacos , Hidrólisis/efectos de los fármacos , Solventes/farmacología , Ácidos Sulfúricos/farmacología , Zea mays/efectos de los fármacos
16.
World J Microbiol Biotechnol ; 28(7): 2551-8, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22806161

RESUMEN

The effects of pH control on the process of acetone/butanol/ethanol (ABE) production in batch cultures of Clostridium acetobutylicum XY16 have been investigated. Based on the specific acid- and solvent-forming rates in batch fermentation at different pH values (from 4.3 to 6.0), a two-stage controlled-pH strategy was developed in which the pH was shifted from 5.5 to 4.9 after a dry cell weight of 0.5 g L(-1) was achieved. By applying this strategy, the maximum ABE concentration and productivity reached 20.3 g L(-1) and 0.63 g L(-1) h (-1), and were significantly improved by 12.2 and 40.1 %, respectively, compared with the process with no pH control. In addition, reducing power capability was significantly enhanced by this strategy. The two-stage controlled-pH strategy was a convenient and rapid method for high intensity ABE production.


Asunto(s)
Biotecnología/métodos , Butanoles/metabolismo , Clostridium acetobutylicum/metabolismo , Concentración de Iones de Hidrógeno
17.
J Ind Microbiol Biotechnol ; 39(3): 401-7, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21789489

RESUMEN

Clostridium beijerinckii mutant strain IB4, which has a high level of inhibitor tolerance, was screened by low-energy ion implantation and used for butanol fermentation from a non-detoxified hemicellulosic hydrolysate of corn fiber treated with dilute sulfuric acid (SAHHC). Evaluation of toxicity showed C. beijerinckii IB4 had a higher level of tolerance than parent strain C. beijerinckii NCIMB 8052 for five out of six phenolic compounds tested (the exception was vanillin). Using glucose as carbon source, C. beijerinckii IB4 produced 9.1 g l(-1) of butanol with an acetone/butanol/ethanol (ABE) yield of 0.41 g g(-1). When non-detoxified SAHHC was used as carbon source, C. beijerinckii NCIMB 8052 grew well but ABE production was inhibited. By contrast, C. beijerinckii IB4 produced 9.5 g l(-1) of ABE with a yield of 0.34 g g(-1), including 2.2 g l(-1) acetone, 6.8 g l(-1) butanol, and 0.5 g l(-1) ethanol. The remarkable fermentation and inhibitor tolerance of C. beijerinckii IB4 appears promising for ABE production from lignocellulosic materials.


Asunto(s)
Clostridium beijerinckii/genética , Tolerancia a Medicamentos/genética , Acetona/metabolismo , Animales , Biodegradación Ambiental , Butanoles/metabolismo , Celulosa/metabolismo , Clostridium beijerinckii/fisiología , Etanol/metabolismo , Fermentación , Glucosa/metabolismo , Mutación , Hidrolisados de Proteína/metabolismo , Zea mays
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