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1.
Phys Chem Chem Phys ; 26(20): 14651-14663, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38743154

RESUMO

H2O in flue gas causes the deactivation of V2O5/TiO2 catalysts for selective catalytic reduction (SCR) of NOx with NH3 at low temperatures. Developing water resistance requires understanding the theoretical mechanism of H2O impact on the catalysts. The aim of this work was to clarify the adsorption process of H2O and the deactivation mechanism induced by H2O through density functional theory (DFT). The process of H2O adsorption was studied based on a modeled V2O5/TiO2 catalyst surface. It was found that H2O had a strong interaction with exposed titanium atoms. Water adsorption on the catalyst surface significantly alters the electronic structure of VOx sites, transforming Lewis acid sites into Brønsted acid sites. Exposed titanium sites contribute to the decrease of Lewis acidity via adsorbed water. Ab initio thermodynamic calculations show that H2O adsorption on V2O5/TiO2 is stable at low coverage but less favorable at high coverage. Adsorption of NH3 is the most critical step for the SCR of NOx, and the adsorption of H2O can hinder this process. The H2O coverage below 15% of adsorption sites could enhance the NH3 adsorption rate and have a limited effect on the acidity, while higher coverage impeded the adsorption ability of VOx sites. This work provided electron-scale insight into the adsorption impact of H2O on the surface of V2O5/TiO2 catalysts, presented thermodynamic analysis of the adsorption of H2O and NH3, paving the way for the exploration of V2O5/TiO2 catalysts with improved water resistance.

2.
J Dairy Sci ; 107(1): 123-140, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37641256

RESUMO

This study aimed to investigate the symbiosis between Streptococcus thermophilus CICC 6038 and Lactobacillus delbrueckii ssp. bulgaricus CICC 6047. In addition, the effect of their different inoculum ratios was determined, and comparison experiments of fermentation characteristics and storage stability of milk fermented by their monocultures and cocultures at optimal inoculum ratio were performed. We found the time to obtain pH 4.6 and ΔpH during storage varied among 6 inoculum ratios (1:1, 2:1, 10:1, 19:1, 50:1, 100:1). By the statistical model to evaluate the optimal ratio, the ratio of 19:1 was selected, which exhibited high acidification rate and low postacidification with pH values remaining between 4.2 and 4.4 after a 50-d storage. Among the 3 groups included in our analyses (i.e., the monocultures of S. thermophilus CICC 6038 [St] and Lb. bulgaricus CICC 6047 [Lb] and their cocultures [St+Lb] at 19:1), the coculture group showed higher acidification activity, improved rheological properties, richer typical volatile compounds, more desirable sensor quality after the fermentation process than the other 2 groups. However, the continuous accumulation of acetic acid during storage showed that acetic acid was more highly correlated with postacidification than d-lactic acid for the Lb group and St+Lb group. Our study emphasized the importance of selecting an appropriate bacterial consortium at the optimal inoculum ratio to achieve favorable fermentation performance and enhanced postacidification stability during storage.


Assuntos
Lactobacillus delbrueckii , Iogurte , Animais , Iogurte/microbiologia , Streptococcus thermophilus , Fermentação , Acetatos
3.
Sensors (Basel) ; 23(19)2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37836964

RESUMO

Recently, deep learning models have been widely applied to modulation recognition, and they have become a hot topic due to their excellent end-to-end learning capabilities. However, current methods are mostly based on uni-modal inputs, which suffer from incomplete information and local optimization. To complement the advantages of different modalities, we focus on the multi-modal fusion method. Therefore, we introduce an iterative dual-scale attentional fusion (iDAF) method to integrate multimodal data. Firstly, two feature maps with different receptive field sizes are constructed using local and global embedding layers. Secondly, the feature inputs are iterated into the iterative dual-channel attention module (iDCAM), where the two branches capture the details of high-level features and the global weights of each modal channel, respectively. The iDAF not only extracts the recognition characteristics of each of the specific domains, but also complements the strengths of different modalities to obtain a fruitful view. Our iDAF achieves a recognition accuracy of 93.5% at 10 dB and 0.6232 at full signal-to-noise ratio (SNR). The comparative experiments and ablation studies effectively demonstrate the effectiveness and superiority of the iDAF.

4.
Int J Mol Sci ; 24(21)2023 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-37958715

RESUMO

Persimmon is a fruit that contains sugars, vitamins, phenolic compounds, and various other nutrients. The aim of this study was to explore the structure of carboxymethylated persimmon polysaccharide (CM-PFP) and its interaction with the human gut microbiota. Carboxymethyl modification of the persimmon polysaccharide (PFP) increased both the Mw and Mn, enhanced dispersion stability, and decreased thermal stability. Both PFP and CM-PFP promoted the proliferation of Lactobacillus while inhibiting the proliferation of Staphylococcus aureus and Escherichia coli. In the simulated fecal fermentation, the pH of PFP- and CM-PFP-containing media decreased, the content of short-chain fatty acids increased, and the abundance of intestinal flora at the phylum and genus levels changed. The relative abundance of harmful intestinal bacteria was significantly reduced in both PFP and CM-PFP groups. Furthermore, it was found that CM-PFP was more easily metabolized than PFP, glucose, and fructo-oligosaccharide (FOS) and had a proliferation increase effect on Lactobacillus. Therefore, CM-PFP has a significant positive effect on both Lactobacillus proliferation and the human gut microbiota.


Assuntos
Diospyros , Microbioma Gastrointestinal , Humanos , Frutas/química , Diospyros/química , Polissacarídeos/química , Proliferação de Células
5.
Int J Mol Sci ; 25(1)2023 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-38203433

RESUMO

This study explored the physicochemical properties and prebiotic activities of glucans and oligoglucans. Oligoglucans were obtained through the fermentation of Leuconostoc mesenteroides CICC6055 and the glucansucrase of strain CICC6055, while glucans were obtained only through fermentation. Thin-layer chromatography and high-performance liquid chromatography identified enzymatically synthesized oligoglucans with a higher yield. Differential scanning calorimetry and derivative thermogravimetry analyses revealed the heat resistance of the glucans and oligoglucans at 280-300 °C. Fourier transform-infrared spectroscopy and nuclear magnetic resonance analyses demonstrated that their main chains were linked with α-1,6-glycosidic bonds accompanied by glucose residue branching. In vitro fermentation experiments demonstrated that they not only improved the contents of short-chain fatty acids but also raised the abundance of predominant flora, such as Bacteroides, Firmicutes, Verrucomicrobia, and Proteobacteria. These results implicate glucansucrase as an efficacious tool for the enzyme synthesis of oligoglucans. Furthermore, both polysaccharides with different degrees of polymerization may be beneficial in maintaining a healthy human gut.


Assuntos
Glucanos , Leuconostoc mesenteroides , Humanos , Polimerização , Bacteroides , Varredura Diferencial de Calorimetria
6.
Molecules ; 28(17)2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37687118

RESUMO

The ethylenediamine-N,N'-disuccinic acid (EDDS) was utilized to form Fe-EDDS complex to activate peroxymonosulfate (PMS) in the electrochemical (EC) co-catalytic system for effective oxidation of naphthenic acids (NAs) under neutral pH conditions. 1-adamantanecarboxylic acid (ACA) was used as a model compound to represent NAs, which are persistent pollutants that are abundantly present in oil and gas field wastewater. The ACA degradation rate was significantly enhanced in the EC/PMS/Fe(III)-EDDS system (96.6%) compared to that of the EC/PMS/Fe(III) system (65.4%). The addition of EDDS led to the formation of a stable complex of Fe-EDDS under neutral pH conditions, which effectively promoted the redox cycle of Fe(III)-EDDS/Fe(II)-EDDS to activate PMS to generate oxidative species for ACA degradation. The results of quenching and chemical probe experiments, as well as electron paramagnetic resonance (EPR) analysis, identified significant contributions of •OH, 1O2, and SO4•- in the removal of ACA. The ACA degradation pathways were revealed based on the results of high resolution mass spectrometry analysis and calculation of the Fukui index. The presence of anions, such as NO3-, Cl-, and HCO3-, as well as humic acids, induced nonsignificant influence on the ACA degradation, indicating the robustness of the current system for applications in authentic scenarios. Overall results indicated the EC/PMS/Fe(III)-EDDS system is a promising strategy for the practical treatment of NAs in oil and gas field wastewater.

7.
Zhongguo Zhong Yao Za Zhi ; 47(10): 2614-2622, 2022 May.
Artigo em Chinês | MEDLINE | ID: mdl-35718479

RESUMO

In this study, we used bioinformatic tools to analyze the 3-hydroxy-3-methylglutaryl-CoA reductase(HMGR) genes from Glycyrrhiza uralensis, Artemisia annua, and Arabidopsis thaliana. The results indicated that GuHMGR and AaHMGR contained two transmembrane regions while AtHMGR had three transmembrane regions. GuHMGR, AaHMGR, and AtHMGR all had the active center for catalysis. Three truncated HMGR genes(tHMGRs) of G. uralensi, A. annua, and A. thaliana were respectively ligated to pYES3 vector to construct the recombinant plasmids pYES3-tGuHMGR,pYES3-tAaHMGR,and pYES3-tAtHMGR. Afterwards, the control plasmid pYES3 and the three plasmids and were respectively introduced into Saccharomyces cerevisiae Cen.pk2-1 D, which yielded strains Y0, Y1, Y2, and Y3, respectively. The content of squalene, lanosterol, and ergosterol in these strains was measured by GC-MS. The relative expression of tGuHMGR, tAaHMGR, and tAtHMGR in strains Y1, Y2, and Y3 was determined by quantitative real-time PCR. The results showed that the strain overexpressing tAaHMGR had the highest yield of squalene and the highest total yield of squalene, ergosterol, and lanosterol. The quantitative real-time PCR showed higher relative expression of tAaHMGR than tGuHMGR, consistent with the strain fermentation result. We selected a superior tHMGR by comparing the effects of different tHMGRs on the mevalonate(MVA) pathway flux in S. cerevisiae. The findings can provide a reference for the construction of S. cerevisiae strains with high yields of squalene and terpenoid precursors.


Assuntos
Ácido Mevalônico , Saccharomyces cerevisiae , Ergosterol , Lanosterol , Ácido Mevalônico/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Esqualeno/metabolismo
8.
Molecules ; 25(4)2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32102411

RESUMO

The study describes sulfuric acid pretreatment of straw from Secale cereale L. (rye straw) to evaluate the effect of acid concentration and treatment time on the efficiency of biofuel production. The highest ethanol yield occurred after the enzyme treatment at a dose of 15 filter paper unit (FPU) per gram of rye straw (subjected to chemical hydrolysis with 2% sulfuric acid (SA) at 121 °C for 1 h) during 120 h. Anaerobic digestion of rye straw treated with 10% SA at 121 °C during 1 h allowed to obtain 347.42 L methane/kg volatile solids (VS). Most hydrogen was released during dark fermentation of rye straw after pretreatment of 2% SA, 121 °C, 1 h and 1% SA, 121 °C, 2 h-131.99 and 134.71 L hydrogen/kg VS, respectively. If the rye straw produced in the European Union were processed into methane, hydrogen, ethanol, the annual electricity production in 2018 could reach 9.87 TWh (terawatt-hours), 1.16 TWh, and 0.60 TWh, respectively.


Assuntos
Etanol/metabolismo , Hidrogênio/metabolismo , Metano/biossíntese , Secale/química , Ácidos Sulfúricos/química , Bactérias/metabolismo , Biocombustíveis/provisão & distribuição , Fermentação , Temperatura Alta , Humanos , Hidrólise , Caules de Planta/química , Energia Renovável
9.
J Sci Food Agric ; 99(6): 3078-3085, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30506690

RESUMO

BACKGROUND: Peptides can act as antioxidants in emulsion, although the mechanism involved is poorly understood. Caragana ambigua seed is a potential protein source for which the commercial applications have not been explored yet. In the present study, we aimed to evaluate the bio-economic potential of C. ambigua by isolating and characterizing antioxidative peptides from the protein hydrolysate of its seeds for the purpose of protecting lipids from oxidation. RESULTS: A novel decapeptide, identified as QITEGEDGGG, was purified by high-protein liquid chromotography based on the enrichment of antioxidant fractions, and its antioxidative activity for walnut oil was evaluated in terms of its effect on oil quality, primary and secondary peroxide formation, oxidation kinetics, and structure of oil droplets. A molecular simulation involving the peptide and fatty acid was carried out aiming to understand the mechanism underlying the prevention of lipid oxidation by the peptide. The peptide effectively scavenged superoxide anions (86.46%), inhibited the rate of linoleic acid oxidation (60.37%) and delayed auto-oxidation of walnut oil. Its inhibition of lipid oxidation was attributed to the protection of phenolic compounds and polyunsaturated fatty acids of walnut oil. CONCLUSION: The findings of the present study will help in the exploitation of novel antioxidant peptides of lipids from woody seed-based protein sources such the seeds of C. ambigua trees. © 2018 Society of Chemical Industry.


Assuntos
Antioxidantes/química , Caragana/química , Lipídeos/química , Peptídeos/química , Antioxidantes/isolamento & purificação , Ácidos Graxos/química , Oxirredução , Peptídeos/isolamento & purificação , Hidrolisados de Proteína/química , Hidrolisados de Proteína/isolamento & purificação , Sementes/química
10.
Microb Cell Fact ; 17(1): 85, 2018 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-29866124

RESUMO

BACKGROUND: Geranyl acetate is widely used in the fragrance and cosmetic industries, and thus has great economic value. However, plants naturally produce a mixture of hundreds of esters, and geranyl acetate is usually only present in trace amounts, which makes its economical extraction from plant sources practically impossible. As an ideal host for heterologous production of fragrance compound, the Saccharomyces cerevisiae has never been engineered to produce the esters, such as geranyl acetate. RESULTS: In this study, a heterologous geranyl acetate synthesis pathway was constructed in S. cerevisiae for the first time, and a titer of 0.63 mg/L geranyl acetate was achieved. By expressing an Erg20 mutant to divert carbon flux from FPP to GPP, the geranyl acetate production increased to 2.64 mg/L. However, the expression of heterologous GPP had limited effect. The highest production of 13.27 mg/L geranyl acetate was achieved by additional integration and expression of tHMG1, IDI1 and MAF1. Furthermore, through optimizing fermentation conditions, the geranyl acetate titer increased to 22.49 mg/L. CONCLUSIONS: We constructed a monoterpene ester producing cell factory in S. cerevisiae for the first time, and demonstrated the great potential of this system for the heterologous production of a large group of economically important fragrance compounds.


Assuntos
Acetatos/metabolismo , Ésteres/metabolismo , Monoterpenos/metabolismo , Saccharomyces cerevisiae/patogenicidade , Terpenos/metabolismo , Engenharia Tecidual/métodos , Monoterpenos Acíclicos
11.
J Food Sci Technol ; 55(6): 2240-2250, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29892124

RESUMO

This study aimed to investigate the effect of Lactobacillus plantarum strains on quality improvement of bog bilberry juice. Bog bilberry juice with different pH conditions was fermented by Lactobacillus B7 or C8-1 strain. Physicochemical index, amino acids, phenolic compounds, and volatiles of these fermented juices were compared. Results indicated that Lactobacillus plantarum strains preferred to metabolize malic acid and reducing sugar in non-pH-adjusted juice (NJ, pH 2.65), whereas quinic and citric acids were largely consumed in pH-adjusted juice (AJ, pH 3.50). Shikimic acid and aromatic amino acids were significantly accumulated in pH-adjusted juice, and phenolic compounds in both juices were significantly reduced. These strains enhanced the composition and concentration of volatiles compounds in non-pH-adjusted juice and improved the floral and fruity flavors. However, concentration and complexity of volatiles were reduced in pH-adjusted juices.

12.
Metab Eng ; 43(Pt A): 85-91, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28688931

RESUMO

Carotenoids are a class of terpenes of commercial interest that exert important biological functions. While various strategies have been applied to engineer ß-carotene production in microbial cell factories, no work has been done to study and improve the storage of hydrophobic terpene products inside the heterologous host cells. Although the membrane is thought to be the cell compartment that accumulates hydrophobic terpenes such as ß-carotene, direct evidence is still lacking. In this work, we engineered the membrane of Escherichia coli in both its morphological and biosynthetic aspects, as a means to study and improve its storage capacity for ß-carotene. Engineering the membrane morphology by overexpressing membrane-bending proteins resulted in a 28% increase of ß-carotene specific producton value, while engineering the membrane synthesis pathway led to a 43% increase. Moreover, the combination of these two strategies had a synergistic effect, which caused a 2.9-fold increase of ß-carotene specific production value (from 6.7 to 19.6mg/g DCW). Inward membrane stacks were observed in electron microscopy images of the engineered E. coli cells, which indicated that morphological changes were associated with the increased ß-carotene storage capacity. Finally, membrane separation and analysis confirmed that the increased ß-carotene was mainly accumulated within the cell membrane. This membrane engineering strategy was also applied to the ß-carotene hyperproducing strain CAR025, which led to a 39% increase of the already high ß-carotene specific production value (from 31.8 to 44.2mg/g DCW in shake flasks), resulting in one of the highest reported specific production values under comparable culture conditions. The membrane engineering strategy developed in this work opens up a new direction for engineering and improving microbial terpene producers. It is quite possible that a wide range of strains used to produce hydrophobic compounds can be further improved using this novel engineering strategy.


Assuntos
Membrana Celular/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Engenharia Genética , Proteínas de Membrana/metabolismo , beta Caroteno/biossíntese , Membrana Celular/genética , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Membrana/genética , beta Caroteno/genética
13.
World J Microbiol Biotechnol ; 33(8): 156, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28702797

RESUMO

Vibrio parahaemolyticus: is recognized as the main cause of gastroenteritis associated with consumption of seafood. Bacteriocin-producing Lactobacillus plantarum FGC-12 isolated from golden carp intestine had strong antibacterial activity toward V. parahaemolyticus. The fish-borne bacteriocin was purified by a three-step procedure consisting of ethyl acetate extraction, gel filtration chromatography and high performance liquid chromatography. Its molecular weight was estimated at 4.1 kDa using SDS-PAGE. The fish-borne bacteriocin reached the maximum production at stationary phase after 20 h. It was heat-stable (30 min at 121 °C) and remained active at pH range from 3.0 to 5.5, but was sensitive to nutrasin, papain and pepsin. Its minimum inhibitory concentration for V. parahaemolyticus was 6.0 mg/ml. Scanning electron microscopy analysis showed that the fish-borne bacteriocin disrupted cell wall of V. parahaemolyticus. The antibacterial mechanism of the fish-borne bacteriocin against V. parahaemolyticus might be described as action on membrane integrity in terms of the leakage of electrolytes, the losses of Na+K+-ATPase, AKP and proteins. The addition of the fish-borne bacteriocin to shrimps leaded V. parahaemolyticus to reduce 1.3 log units at 4 °C storage for 6 day. Moreover, a marked decline in total volatile base nitrogen and total viable counts was observed in bacteriocin treated samples than the control. It is clear that this fish-borne bacteriocin has promising potential as biopreservation for the control of V. parahaemolyticus in aquatic products.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bacteriocinas/isolamento & purificação , Bacteriocinas/farmacologia , Peixes/microbiologia , Lactobacillus plantarum/metabolismo , Penaeidae/microbiologia , Vibrio parahaemolyticus/efeitos dos fármacos , Adenosina Trifosfatases/metabolismo , Animais , Antibacterianos/biossíntese , Antibacterianos/química , Bacteriocinas/biossíntese , Bacteriocinas/química , Permeabilidade da Membrana Celular/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Contagem de Colônia Microbiana , Eletrólitos , Microbiologia de Alimentos , Conservação de Alimentos , Armazenamento de Alimentos , Concentração de Íons de Hidrogênio , Lactobacillus plantarum/isolamento & purificação , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Peso Molecular , Papaína , Pepsina A , Potássio/metabolismo , Alimentos Marinhos , Sódio/metabolismo , Temperatura , Vibrio parahaemolyticus/citologia , Vibrio parahaemolyticus/patogenicidade , Microbiologia da Água
14.
Asian-Australas J Anim Sci ; 30(2): 236-245, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27383799

RESUMO

OBJECTIVE: The study was to investigate the effects of alanyl-glutamine (Ala-Gln) and glutamine (Gln) supplementation on the intestinal mucosa barrier in piglets. METHODS: A total of 180 barrows with initial weight 10.01±0.03 kg were randomly allocated to three treatments, and each treatment consisted of three pens and twenty pigs per pen. The piglets of three groups were fed with control diet [0.62% alanine (Ala)], Ala-Gln diet (0.5% Ala-Gln), Gln diet (0.34% Gln and 0.21% Ala), respectively. RESULTS: The results showed that in comparison with control diet, dietary Ala-Gln supplementation increased the height of villi in duodenum and jejunum (p<0.05), Gln supplementation increased the villi height of jejunum (p<0.05), Ala-Gln supplementation up-regulated the mRNA expressions of epidermal growth factor receptor and insulin-like growth factor 1 receptor in jejunal mucosa (p<0.05), raised the mRNA expressions of Claudin-1, Occludin, zonula occludens protein-1 (ZO-1) and the protein levels of Occludin, ZO-1 in jejunal mucosa (p<0.05), Ala-Gln supplementation enlarged the number of goblet cells in duodenal and ileal epithelium (p<0.05), Gln increased the number of goblet cells in duodenal epithelium (p<0.05) and Ala-Gln supplementation improved the concentrations of secretory immunoglobulin A and immunoglobulin G in the jejunal mucosa (p<0.05). CONCLUSION: These results demonstrated that dietary Ala-Gln supplementation could maintain the integrity of small intestine and promote the functions of intestinal mucosa barriers in piglets.

15.
Molecules ; 21(10)2016 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-27706098

RESUMO

This study investigated the effect of raw material, pressing, and glycosidase on the aromatic profile of goji berry wine. The free-run and the pressed juice of dried and fresh goji berries were used for wine production, whereas glycosidase was applied to wine after fermentation. Dried goji berry fermented wine exhibited much stronger fruity, floral, caramel, and herbaceous odors due to higher levels of esters, ß-ionone and methionol. However, fresh berry fermented wine possessed stronger chemical notes due to higher levels of 4-ethylphenol. Pressing treatment reduced the fruity and caramel odors in these fermented wines, and fresh berry free-run juice fermented wine exhibited the least floral aroma. Glycosidase addition did not alter the aromatic composition of wines. The principal component analysis indicated that goji raw material played a primary role in differentiating the aromatic profiles of the wines due to the difference on the content of 20 esters, nine benzenes, eight aldehydes/ketones, three acids, two alcohols and six other volatiles. The content differences on isopentyl alcohol, styrene, benzyl alcohol, 1-octanol, (E)-5-decen-1-ol, 1-hexanol, and ß-cyclocitral resulted in the segregation of the wines with and without the pressing treatment, especially for fresh berry fermented wine.


Assuntos
Glicosídeo Hidrolases/metabolismo , Lycium/química , Compostos Orgânicos Voláteis/análise , Vinho/análise , Fermentação , Aromatizantes/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Análise de Componente Principal , Olfato
16.
Molecules ; 22(1)2016 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-28036078

RESUMO

A nitrogen deficiency always causes bog bilberry syrup wine to have a poor sensory feature. This study investigated the effect of nitrogen source addition on volatile compounds during bog bilberry syrup wine fermentation. The syrup was supplemented with 60, 90, 120 or 150 mg/L dibasic ammonium phosphate (DAP) before fermentation. Results showed that an increase of DAP amounts accelerated fermentation rate, increased alcohol content, and decreased sugar level. Total phenol and total flavonoid content were also enhanced with the increase of DAP amounts. A total of 91 volatile compounds were detected in the wine and their concentrations were significantly enhanced with the increase of DAP. Ethyl acetate, isoamyl acetate, phenethyl acetate, ethyl butanoate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, isobutanol, isoamyl alcohol, levo-2,3-butanediol, 2-phenylethanol, meso-2,3-butanediol, isobutyric acid, hexanoic acid, and octanoic acid exhibited a significant increase of their odor activity value (OAV) with the increase of DAP amounts. Bog bilberry syrup wine possessed fruity, fatty, and caramel flavors as its major aroma, whereas a balsamic note was the least present. The increase of DAP amounts significantly improved the global aroma attributes, thereby indicating that DAP supplementation could promote wine fermentation performance and enhance the sensory quality of bog bilberry syrup wine.


Assuntos
Aromatizantes/análise , Odorantes/análise , Fosfatos/química , Vinho/análise , Aldeídos/análise , Antocianinas/análise , Ésteres/análise , Fermentação , Flavonoides/análise , Cetonas/análise , Fenóis/análise , Vaccinium myrtillus , Compostos Orgânicos Voláteis/análise
17.
Wei Sheng Wu Xue Bao ; 56(5): 814-23, 2016 May 04.
Artigo em Chinês | MEDLINE | ID: mdl-29727143

RESUMO

Objective: The performances of Lactobacillus acidophilus NCFM, Lactobacillus plantarum121 and Lactobacillus pentosus ML32 in removing benzo(a)pyrene [B(a)P] in simulated starch conditions were studied. To provide a novel way to reduce the potential risk of B(a)P to human, several factors which affect the binding of the 3 Lactobacillus strains to the chemical toxin were investigated in starch system. Methods: The percentage of B(a)P bound by Lactobacillus strains was determined with HPLC after incubation at 37℃ for 4 h. The B(a)P-removing capabilities of Lactobacillus strains in various simulated starch systems were evaluated, including the concentrations, types and gelatinization of starch, incubation time, pH and starch-hydrolyzed products. Results: The B(a)P-binding percentages of the Lactobacillus strains increased as starch concentrations were elevated from 2% to 10%. Starch types, either from corn, potato or sweet potato, had little effects on the ability of these bacterial cells to bind B(a)P. The gelatinization of starch favored Lactobacillus strains to bind more B(a)P. The percentage of these bacterial cells to bind B(a)P grew fast at 37℃ for the first 4 h-incubation time, and then slowly increased. The three Lactobacillus strains bound more B(a)P when starches were acidified to pH of 3 to 4 or alkalified to pH of 8 to 9. The viable cells of three Lactobacillus strains removed more B(a)P via their binding than their dead cells did. Moreover, both glucose and maltose, the end products after starch is hydrolyzed, improved significantly the performance of the 3 bacterial strains to remove B(a)P. Conclusion: All of the three Lactobacillus strains perform good ability to bind B(a)P in the presences of starch. Their B(a)P-removing ability would be improved with an increased starch concentration, and the gelatinization of starch as well as the supplements of glucose and maltose. Thus, the selected Lactobacillus strains in our current work should be promising as a biological agent to reduce the occurrence of B(a)P in starch-based food products.


Assuntos
Benzo(a)pireno/metabolismo , Lactobacillus/metabolismo , Humanos , Modelos Biológicos , Amido/metabolismo , Zea mays/metabolismo , Zea mays/microbiologia
18.
BMC Complement Altern Med ; 15: 413, 2015 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-26593407

RESUMO

BACKGROUND: Walnut is unique because they have a perfect balance of n-6 and n-3 polyunsaturated fatty acids. The increasing market demand of walnut lipids results in the large amount of the oil extraction residue. The walnut residue is rich in nutritional proteins, and the uneconomic use of the by-product discouraged the development of walnut industry. Anticancer peptides have recently received attention as alternative chemotherapeutic agents that overcome the limits of current drugs. The aim of this study was to investigate whether anticancer bioactive peptide is contained in walnut. METHODS: Walnut residual protein was hydrolyzed separately by five different proteases. The sequential purification of the hydrolysates was carried out by ultra-filtration, gel filtration chromatography and RP-HPLC to obtain a cancer cell growth inhibitory peptide. Cell cycle distribution, Annexin V-FITC/PI double staining, TUNEL assay, western blot and immunofluorescence for LC3-II assay were used to detect apoptosis and autophagy on cells. Cytokine production was measured by ELISA kits, macrophage phagocytosis was measured by neutral red uptake assay, nitric oxide production was measured by Griess reagent. RESULTS: The hydrolysates of walnut residual protein produced by papain under the optimal conditions (5 % substrate concentration and an enzyme-substrate ratio of 10 % at temperature 60 C for 3 h), showed significant growth inhibitory activity on MCF-7. The amino acid sequence of the purified peptide was identified as CTLEW with a molecular weight of 651.2795 Da. It is a novel bio-peptide with an amphiphilic structure. CTLEW induced both apoptosis and autophagy on MCF-7 cells, inhibited the cancer cells growth of Caco-2 and HeLa significantly, but did not show any cytotoxic activity against non-cancerous IEC-6 cells. Moreover, the bio-peptide enhanced proliferation and IL-2 secretion of spleen lymphocytes, promoted phagocytosis and NO production of macrophages. CONCLUSION: These results suggested that a novel bio-peptide, CTLEW inducing apoptosis and autophagy on MCF-7 cells can be released from walnut residual protein through papain hydrolyzing under the certain condition. The bio-peptide shows selective inhibition towards cancer cells growth and immunomodulatory activity.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Juglans/química , Neoplasias/patologia , Peptídeos/isolamento & purificação , Peptídeos/farmacologia , Proteínas de Plantas/química , Sequência de Aminoácidos , Animais , Antineoplásicos/química , Antineoplásicos/imunologia , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Células CACO-2 , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Humanos , Interleucina-2/metabolismo , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Células MCF-7 , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Peso Molecular , Neoplasias/imunologia , Óxido Nítrico/metabolismo , Nozes/química , Papaína/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Fagocitose/efeitos dos fármacos , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo
19.
Molecules ; 20(11): 19865-77, 2015 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-26556321

RESUMO

Phenolic compounds determine the color quality of fruit wines. In this study, the phenolic compound content and composition, color characteristics and changes during 6 months of bottle aging were studied in wines fermented with bog bilberry syrup under three different pHs. The total anthocyanins and total phenols were around 15.12-16.23 mg/L and 475.82 to 486.50 mg GAE/L in fresh wines and declined 22%-31% and about 11% in bottle aged wines, respectively. In fresh wines, eight anthocyanins, six phenolic aids and 14 flavonols, but no flavon-3-ols were identified; Malvidin-3-O-glucoside, petunidin-3-O-glucoside and delphinium-3-O-glucoside were the predominant pigments; Chlorogentic acid was the most abundant phenolic acid, and quercetin-3-O-galactoside and myricetin-3-O-galactoside accounted for nearly 90% of the total flavonols. During 6 months of bottle storage, the amounts of all the monomeric anthocyanins and phenolic acids were reduced dramatically, while the glycosidyl flavonols remained constant or were less reduced and their corresponding aglycones increased a lot. The effects of aging on blueberry wine color were described as the loss of color intensity with a dramatic change in color hue, from initial red-purple up to final red-brick nuances, while the pH of the fermentation matrix was negatively related to the color stability of aged wine.


Assuntos
Polifenóis/química , Vaccinium myrtillus/química , Vinho/análise , Antocianinas/química , Fermentação , Flavonóis/química , Concentração de Íons de Hidrogênio , Hidroxibenzoatos/química , Fenóis/química , Pigmentos Biológicos/análise
20.
Int J Syst Evol Microbiol ; 64(Pt 1): 206-210, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24048866

RESUMO

Daqu is a fermentation starter used in the production of Chinese liquors. A thermophilic bacterium, designated strain H-18(T), was isolated from a high-temperature Daqu sample collected from the manufacturing process of a sesame-flavoured liquor in Shandong province, China. It was investigated in a taxonomic study using a polyphasic approach. Strain H-18(T) formed white aerial mycelium and greyish-yellow substrate mycelium, bearing single endospores on aerial and substrate hyphae or on unbranched short sporophores. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The major fatty acids were iso-C15 : 0 and iso-C17 : 0. The predominant menaquinone was MK-7. These chemotaxonomic properties are similar to those of members of the genus Thermoactinomyces. The G+C content of the genomic DNA was 49.1 mol%. 16S rRNA gene sequence comparisons indicated that strain H-18(T) was most closely related to Thermoactinomyces vulgaris KCTC 9076(T) (96.42 % similarity), Thermoactinomyces intermedius KCTC 9646(T) (96.06 %), Laceyella putida KCTC 3666(T) (96.32 %) and Laceyella sacchari KCTC 9790(T) (95.55 %). Strain H-18(T) showed low DNA-DNA relatedness (40.8, 33.4, 20.0 and 14.4 %) with the above strains. Based on morphological and chemotaxonomic characteristics, DNA-DNA hybridization data and physiological properties, strain H-18(T) represents a novel species of the genus Thermoactinomyces, for which the name Thermoactinomyces daqus sp. nov. is proposed. The type strain is H-18(T) ( = DSM 45914(T) = CICC 10681(T)).


Assuntos
Bebidas Alcoólicas/microbiologia , Filogenia , Thermoactinomyces/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Fermentação , Temperatura Alta , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Esporos Bacterianos , Thermoactinomyces/genética , Thermoactinomyces/isolamento & purificação , Vitamina K 2/análogos & derivados , Vitamina K 2/química
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