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1.
Food Chem ; 302: 125335, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31416001

RESUMO

Cocoa bean fermentation still remains a rather empirical process. The research presented here employed an artificial system of fermentation, using controlled incubations, in order to achieve greater control over the external influences that cocoa beans are exposed to, with the aim of experimentally modelling changes to bean components (responses). Experimental design was used, in a first-ever attempt, to study the effects of five factors and their interactions on the profiles of pH, peptides, and flavanols in the bean during the incubations. Temperature, incubation time and the concentration of acetic acid were the main factors influencing the three responses. Moreover, there was a significant amount of factor interaction, revealing the process to be more complex than initially thought, especially with respect to the role of ethanol. Using the model, one was also able to accurately predict the response of the bean to the exposure to specific factors.


Assuntos
Cacau/metabolismo , Indústria de Processamento de Alimentos/métodos , Modelos Teóricos , Ácido Acético/metabolismo , Cacau/química , Etanol/metabolismo , Fermentação , Concentração de Íons de Hidrogênio , Ácido Láctico/metabolismo , Reprodutibilidade dos Testes , Temperatura Ambiente
2.
Bioresour Technol ; 291: 121849, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31387051

RESUMO

Anaerobic digestion (AD) has been widely applied as an economic option for food waste (FW) treatment. In this study, the group treated with ethanol pre-fermentation (EP) for 12 h (EP12) exhibited the highest cumulative biogas yield (206 mL/g-volatile solid) during AD process and therefore it was used to illuminate the underlying metabolic processes of AD with EP. Carbon isotope labeled glucose was supplemented to FW substrate, and the EP process was found to alleviate the acidification inhibition with conducting extremely high carbon flux towards ethanol formation (43.7%). Then an efficient acetogenesis phase was also observed in EP12 group, because of high carbon conversion rate from ethanol to acetate. Overall, higher carbon conversion rate to methane (90.1%) during methanogenesis was found in the AD system with EP than in the control experiment (80.3%). Thus, we quantitatively confirmed that EP affects the AD metabolism of FW in terms of carbon flow distribution.


Assuntos
Alimentos , Metano/biossíntese , Anaerobiose , Biocombustíveis , Isótopos de Carbono , Etanol/metabolismo , Fermentação , Marcação por Isótopo
3.
Bioresour Technol ; 291: 121573, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31376665

RESUMO

Upgrading lactate/carbohydrate-rich waste biomass into medium-chain carboxylic acids (MCCAs) by chain elongation (CE) technology exhibits economic and environmental benefits. However, the largely dispersive lactate-carbon-flow decreases MCCAs yield. This work discovered appropriate H2 supply could significantly reduce lactate-carbon-flow loss and improve MCCAs production (∼1.65 times) when the system is not operated according to well-defined operating conditions, and revealed corresponding mechanism. Hydrogen (H2) supply largely enhanced electron efficiency and electron transfer capacity, and H2 could reduce propionate (from competing acrylate pathway, which should be prevented, but when not possible, the carbon recovery from propionate is possible) to propanol, which was used as electron donor to elongate acetate and propionate. Moreover, H2 could react with CO2 (from CE process) to sequentially generate acetate and ethanol, which further contributed to caproate/caprylate generation. Comparing with non-H2-supplemented test, the lactate-carbon-flow used for MCCAs production was enhanced by ∼28.4% after H2 supply, and Clostridium spp. were the key discriminative microorganisms.


Assuntos
Carbono/metabolismo , Ácidos Carboxílicos/metabolismo , Hidrogênio/metabolismo , Ácido Láctico/metabolismo , Ácido Acético/metabolismo , Biomassa , Reatores Biológicos , Caproatos/metabolismo , Caprilatos/metabolismo , Etanol/metabolismo , Fermentação
4.
Bioresour Technol ; 291: 121844, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31400704

RESUMO

A low-temperature sodium hydroxide (NaOH) pretreatment for sugarcane bagasse (SCB) was obtained via the surface response design in this study. However, a large quantity of water consumption and wastewater generation which have been the common problems for alkaline pretreatment of lignocellulose still exists in this pretreatment. In order to reduce water consumption and wastewater generation, this study attempted to perform enzymatic hydrolysis and fermentation of NaOH-treated SCB without washing process. It showed that after pretreatment and solid-liquid separation, NaOH-treated SCB could be directly hydrolysed by cellulase via pH and solid-liquid adjustment without washing steps, and the maximum enzymatic hydrolysis efficiency could reach to 70.2%. A domesticated Saccharomyces cerevisiae Y2034 which can endure 6-times diluted BL was obtained, and realized 67.5% ethanol yield from the enzymatic hydrolysate of unwashed NaOH-treated SCB. It provided a clue for converting NaOH-treated lignocellulose to ethanol at low water consumption and wastewater generation.


Assuntos
Celulose/química , Etanol/química , Saccharum/química , Hidróxido de Sódio/química , Celulose/metabolismo , Temperatura Baixa , Etanol/metabolismo , Fermentação , Hidrólise , Lignina/química , Lignina/metabolismo , Saccharomyces cerevisiae/metabolismo , Saccharum/metabolismo , Águas Residuárias/química
5.
World J Microbiol Biotechnol ; 35(9): 136, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31432249

RESUMO

Volatile phenols such as 4-ethylphenol are produced from hydroxycinnamic acids by Dekkera bruxellensis, an important yeast contaminating alcoholic fermentations. 4-ethylphenol results from the decarboxylation and reduction of p-coumaric acid, a compound found in sugarcane musts. In wine, volatile phenols are responsible by sensorial alterations whereas in the context of bioethanol fermentation, little is known about their effects on the main yeast, Saccharomyces cerevisiae. Here we evaluated the interaction of 4-ethylphenol and pH, sucrose and ethanol on the growth and fermentation capacity of the industrial strain of S. cerevisiae PE-2. A central compound rotational design was utilized to evaluate the effect of 4-ethylphenol, pH, ethanol and sucrose concentration on the yeast maximum specific growth rate (µmax) in microplate experiments in YPS medium (Yeast extract-Peptone-Sucrose), at 30 °C. Following, single-cycle fermentations in YPS medium, pH 4.5, 17% sucrose, at 30 °C, with 4-ethylphenol in concentrations of 10 and 20 mg L-1 being added at the start or after 4 h of fermentation, were carried out. 4-ethylphenol affected µmax of S. cerevisiae in situations that resemble the conditions of industrial bioethanol production, especially the low pH of the fermentation medium and the high ethanol concentration because of the anaerobic sucrose uptake. The addition of 4-ethylphenol on fermentation resulted in significant effect on the cell yeast concentration, pH and alcohol production, with significant decrease from 86% to the range of 65-74% in the fermentative efficiency. The industrial yeast S. cerevisiae PE-2 growth and fermentative capacity were affected by the presence of 4-ethylphenol, a metabolite produced by D. bruxellensis, which may contribute to explain the impact of this yeast on bioethanol industrial production.


Assuntos
Etanol/metabolismo , Fermentação , Microbiologia Industrial , Fenóis/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , Sacarose/metabolismo , Meios de Cultura/química , Inibidores do Crescimento/metabolismo , Concentração de Íons de Hidrogênio , Saccharomyces cerevisiae/efeitos dos fármacos , Temperatura Ambiente
6.
Adv Exp Med Biol ; 1193: 1-33, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31368095

RESUMO

Several review articles have been published on the neurobehavioral actions of acetaldehyde and other ethanol metabolites as well as in major alcohol-related disorders such as cancer and liver and lung disease. However, very few reviews dealt with the role of alcohol metabolism in the adverse cardiac and autonomic effects of alcohol and their potential underlying mechanisms, particularly in vulnerable populations. In this chapter, following a brief overview of the dose-related favorable and adverse cardiovascular effects of alcohol, we discuss the role of ethanol metabolism in its adverse effects in the brainstem and heart. Notably, current knowledge dismisses a major role for acetaldehyde in the adverse autonomic and cardiac effects of alcohol because of its low tissue level in vivo. Contrary to these findings in men and male rodents, women and hypertensive individuals are more sensitive to the adverse cardiac effects of similar amounts of alcohol. To understand this discrepancy, we discuss the autonomic and cardiac effects of alcohol and its metabolite acetaldehyde in a model of hypertension, the spontaneously hypertensive rat (SHR) and female rats. We present evidence that enhanced catalase activity, which contributes to cardioprotection in hypertension (compensatory) and in the presence of estrogen (inherent), becomes detrimental due to catalase catalysis of alcohol metabolism to acetaldehyde. Noteworthy, studies in SHRs and in estrogen deprived or replete normotensive rats implicate acetaldehyde in triggering oxidative stress in autonomic nuclei and the heart via (i) the Akt/extracellular signal-regulated kinases (ERK)/nitric oxide synthase (NOS) cascade and (ii) estrogen receptor-alpha (ERα) mediation of the higher catalase activity, which generates higher ethanol-derived acetaldehyde in female heart. The latter is supported by the ability of ERα blockade or catalase inhibition to attenuate alcohol-evoked myocardial oxidative stress and dysfunction. More mechanistic studies are needed to further understand the mechanisms of this public health problem.


Assuntos
Acetaldeído/farmacologia , Fármacos do Sistema Nervoso Autônomo/farmacologia , Etanol/metabolismo , Coração/efeitos dos fármacos , Animais , Feminino , Masculino , Miocárdio , Estresse Oxidativo , Ratos , Ratos Endogâmicos SHR
7.
Bioresour Technol ; 289: 121716, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31323721

RESUMO

This study integrated the sugar and carboxylate platforms to enhance duckweed processing in biorefineries. Two or three bioprocesses (ethanol fermentation, acidogenic digestion, and methanogenic digestion) were sequentially integrated to maximize the carbon-to-carbon conversion of wastewater-derived duckweed into bioproducts, through a series of laboratory-scale experiments. Reactors were fed either raw (dried), liquid-hot-water-pretreated, or enzymatically-saccharified duckweed. Subsequently, the target bioproduct was separated from the reactor liquor and the residues further processed. The total bioproduct carbon yield of 0.69 ±â€¯0.07 g per gram of duckweed-C was obtained by sequential acidogenic and methanogenic digestion. Three sequential bioprocesses revealed nearly as high yields (0.66 ±â€¯0.08 g of bioproduct-C per duckweed-C), but caused more gaseous carbon (dioxide) loss. For this three-stage value cascade, yields of each process in conventional units were: 0.186 ±â€¯0.001 g ethanol/g duckweed; 611 ±â€¯64 mg volatile fatty acids as acetic acid/g VS; and 434 ±â€¯0.2 ml methane/g VS.


Assuntos
Araceae/metabolismo , Águas Residuárias/química , Ácido Acético/metabolismo , Anaerobiose , Araceae/química , Etanol/metabolismo , Euryarchaeota/metabolismo , Fermentação , Metano/biossíntese
8.
J Microbiol Biotechnol ; 29(7): 1043-1052, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31353877

RESUMO

Active lipase-producing bacterium Burkholderia gladioli Bps-1 was rapidly isolated using a modified trypan blue and tetracycline, ampicillin (TB-TA) plate. The electro-phoretically pure enzyme was obtained by purification using ethanol precipitation, ion-exchange chromatography, and gel filtration chromatography. The molecular weight was 34.6 kDa and the specific activity was determined to be 443.9 U/mg. The purified lipase showed the highest activity after hydrolysis with p-NPC16 at a pH of 8.5 and 50°C, and the Km, kcat, and kcat/Km values were 1.05, 292.95 s-1 and 279 s-1mM-1, respectively. The lipase was highly stable at 7.5 ≤ pH ≤ 10.0. K+ and Na+ exerted activation effects on the lipase which had favorable tolerance to short-chain alcohols with its residual enzyme activity being 110% after being maintained in 30% ethanol for 1 h. The results demonstrated that the lipase produced by the strain B. gladioli Bps-1 has high enzyme activity and is an alkaline lipase. The lipase has promising chemical properties for a range of applications in the food-processing and detergent industries, and has particularly high potential for use in the manufacture of biodiesel.


Assuntos
Burkholderia gladioli/enzimologia , Burkholderia gladioli/isolamento & purificação , Lipase/metabolismo , Biocatálise , Biocombustíveis , Burkholderia gladioli/crescimento & desenvolvimento , Burkholderia gladioli/metabolismo , Meios de Cultura , Detergentes , Estabilidade Enzimática , Etanol/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Lipase/química , Lipase/isolamento & purificação , Peso Molecular , Especificidade por Substrato , Temperatura Ambiente
9.
Enzyme Microb Technol ; 129: 109359, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31307575

RESUMO

Thermotolerant yeast Kluyveromyces marxianus can assimilate xylose but cannot produce ethanol from xylose under anaerobic conditions. Here, we constructed two recombinant K. marxianus strains, DMB5 and DMB13, that express xylose reductase (XR), NAD+- or protein-engineered NADP+-dependent xylitol dehydrogenase (XDH), and xylulokinase (XK) from K. marxianus. These strains, together with previously reported strain DMB3-7, which expresses Scheffersomyces stipitis XR and NAD+-dependent XDH and Saccharomyces cerevisiae XK, were compared to evaluate enzymatic activities and ethanol productivities at 30 °C and 40 °C. Unlike the activities of xylose metabolic enzymes in DMB3-7, enzymatic activities of XR, XDH, and XK in both DMB5 and DMB13 hardly decreased even at 40 °C, suggesting that these enzymes from K. marxianus are highly thermostable. The most efficient glucose/xylose co-fermentation at 40 °C was found in DMB13; namely, DMB13 rapidly converted xylose to ethanol, especially after glucose depletion, and showed the highest ethanol yield (0.402 g/g). These findings support the view that alteration of coenzyme specificity of XDH expressed in K. marxianus will be efficacious for high-temperature ethanol production from mixed sugars containing xylose.


Assuntos
Etanol/metabolismo , Kluyveromyces/metabolismo , Xilose/metabolismo , Aldeído Redutase/química , Aldeído Redutase/genética , Aldeído Redutase/metabolismo , D-Xilulose Redutase/química , D-Xilulose Redutase/genética , D-Xilulose Redutase/metabolismo , Fermentação , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Temperatura Alta , Kluyveromyces/química , Kluyveromyces/enzimologia , Kluyveromyces/genética , Temperatura Ambiente , Xilitol/metabolismo
10.
Enzyme Microb Technol ; 129: 109352, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31307579

RESUMO

Present study reports modulation in butanol biosynthesis in Clostridium acetobutylicum ATCC 824 under the influence of zinc supplementation or magnesium starvation either individually or in combination. An improvement in butanol titer from 11.83 g L-1 in control to 13.72 g L-1, 15.79 g L-1, and 19.18 g L-1 was achieved when organism was grown on magnesium starved, zinc supplemented and combined zinc supplemented-magnesium starved fermentation medium, respectively. The elevation in butanol biosynthesis was associated with raised glucose utilization, reduced ethanol production and early induction of solventogenesis. Change in these phenotypic traits of the organism may be attributed to multi-level modulation in central carbon metabolism e.g., upregulation of glycolytic pathway; upregulation in thiolase activity; key intermediate enzyme for biosynthesis of acids and solvent; upregulation in the activity of butyrylaldehyde dehydrogenase & butanol dehydrogenase, the enzymes responsible for butanol biosynthesis and downregulation in alcohol dehydrogenase, redirecting carbon flux from ethanol to butanol.


Assuntos
Butanóis/metabolismo , Clostridium acetobutylicum/metabolismo , Magnésio/metabolismo , Zinco/metabolismo , Etanol/metabolismo , Fermentação , Glucose/metabolismo , Magnésio/análise , Zinco/análise
11.
Food Chem ; 298: 125017, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260967

RESUMO

The aim of the study was to evaluate an elevated (3.0 °C) and low (1.0 °C) storage temperature combined with dynamic controlled atmosphere monitored by respiratory quotient (DCA-RQ) and chlorophyll fluorescence (DCA-CF) on anaerobic metabolism, physiological storage disorders and overall quality of 'Nicoter' ('Kanzi®') apples after 5.5 and 8.0 months of storage plus 7d shelf-life. Fruit stored under DCA-RQ 2.0 accumulated the highest amounts of anaerobic metabolites (acetaldehyde, ethanol and ethyl acetate), regardless of storage temperature and timing of storage outturn evaluation, but it did not result in higher electrolyte leakage. Flesh breakdown, core breakdown and cavity formation were reduced at 3 °C. Storage at 3 °C combined with DCA maintained higher flesh firmness after 8.0 months storage plus 7d shelf-life. 'Nicoter' apples can be stored at 3 °C using a DCA system, based either on CF or on RQ, to save electrical energy.


Assuntos
Armazenamento de Alimentos/métodos , Frutas/metabolismo , Malus/metabolismo , Acetaldeído/metabolismo , Acetatos/metabolismo , Anaerobiose , Atmosfera , Clorofila/metabolismo , Etanol/metabolismo , Fluorescência , Temperatura Ambiente
12.
Prep Biochem Biotechnol ; 49(8): 830-836, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31274051

RESUMO

The current study evaluated the production and characterization of ß-glucosidase by the thermophilic fungus Thermomucor indicae-seudaticae in solid-state fermentation of wheat bran. Isolated fungi have significant amounts of ß-glucosidase, an enzyme that may be applied to different industrial processes, such as the production of fuels, food, and other chemical compounds. Maximal enzyme activity occurred in pH 3.5-4.5 and at 70 °C. The enzyme exhibited high thermostability, for 1 h, up to 60 °C, and good tolerance to glucose (10 mM) and ethanol (10%). The optimization of fermentative parameters on the production of ß-glucosidase was carried out by evaluating the best supplementary nutrient source, pH of nutrient solution, initial substrate moisture and fermentation temperature. The optimization of the above fermentation parameters increased enzyme activity by 120.0%. The highest enzymatic activity (164.0 U/g) occurred with wheat bran containing 70% initial moisture, supplemented with 1.0% (NH4)2SO4 solution at pH 5.5-6.0 and fungus incubated at 40 °C. A more detailed study of ß-glucosidase suggested that Sulfur is an important component of the main amino acid present in this enzyme. The enhancer of the enzyme activity occurred when the fungus was grown on wheat bran supplemented with a sulfur-containing solution. In fact, increasing the concentration of sulfur in the solution increased its activity.


Assuntos
Fibras na Dieta/metabolismo , Microbiologia Industrial/métodos , Mucorales/metabolismo , beta-Glucosidase/metabolismo , Estabilidade Enzimática , Etanol/metabolismo , Fermentação , Glucose/metabolismo , Íons/metabolismo
13.
Sci Total Environ ; 690: 956-964, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31302559

RESUMO

In present study, a potential bacterial isolate Acetobacter pasteurianus SKYAA25 was found to be very effective in the bioconversion of apple pomace to acetic acid. The isolated strain was tolerant to high ethanol concentrations of upto 14% and temperature of 42 °C. Fermentation of apple pomace alone in presence of brewing yeast produced 7.3% of bio-ethanol which was further used for acetic acid production. Apple pomace in combination with cane molasses produced 14% of bio-ethanol. The fermented bio-ethanol was used as medium for acetic acid production which yielded 52.4 g of acetic acid/100 g of DM (Dry Matter) of apple pomace. Hence, an ecofriendly process has been developed that is entirely based on microbial processing of apple pomace to produce acetic acid without involving commercial enzymes. The present bio-conversion will prove to be beneficial for utilizing food and beverage industrial waste in the production of acetic acid.


Assuntos
Ácido Acético/metabolismo , Acetobacter/fisiologia , Adaptação Fisiológica/fisiologia , Etanol/metabolismo , Fermentação , Malus/microbiologia , Saccharomyces cerevisiae , Água/metabolismo
14.
Nat Commun ; 10(1): 2486, 2019 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-31171782

RESUMO

Although brown macroalgae holds potential as an alternative feedstock, its utilization by conventional microbial platforms has been limited due to the inability to metabolize one of the principal sugars, alginate. Here, we isolate Vibrio sp. dhg, a fast-growing bacterium that can efficiently assimilate alginate. Based on systematic characterization of the genomic information of Vibrio sp. dhg, we establish a genetic toolbox for its engineering. We also demonstrate its ability to rapidly produce ethanol, 2,3-butanediol, and lycopene from brown macroalgae sugar mixture with high productivities and yields. Collectively, Vibrio sp. dhg can be used as a platform for the efficient conversion of brown macroalgae sugars into diverse value-added biochemicals.


Assuntos
Feófitas/metabolismo , Alga Marinha/metabolismo , Vibrio/metabolismo , Alginatos/metabolismo , Butileno Glicóis/metabolismo , Etanol/metabolismo , Licopeno/metabolismo , Manitol/metabolismo
15.
Chemosphere ; 231: 588-606, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31154237

RESUMO

Tremendous explosion of population has led to about 200% increment of total energy consumptions in last twenty-five years. Apart from conventional fossil fuel as limited energy source, alternative non-conventional sources are being explored worldwide to cater the energy requirement. Lignocellulosic biomass conversion for biofuel production is an important alternative energy source due to its abundance in nature and creating less harmful impacts on the environment in comparison to the coal or petroleum-based sources. However, lignocellulose biopolymer, the building block of plants, is a recalcitrant substance and difficult to break into desirable products. Commonly used chemical and physical methods for pretreating the substrate are having several limitations. Whereas, utilizing microbial potential to hydrolyse the biomass is an interesting area of research. Because of the complexity of substrate, several enzymes are required that can act synergistically to hydrolyse the biopolymer producing components like bioethanol or other energy substances. Exploring a range of microorganisms, like bacteria, fungi, yeast etc. that utilizes lignocelluloses for their energy through enzymatic breaking down the biomass, is one of the options. Scientists are working upon designing organisms through genetic engineering tools to integrate desired enzymes into a single organism (like bacterial cell). Studies on designer cellulosomes and bacteria consortia development relating consolidated bioprocessing are exciting to overcome the issue of appropriate lignocellulose digestions. This review encompasses up to date information on recent developments for effective microbial degradation processes of lignocelluloses for improved utilization to produce biofuel (bioethanol in particular) from the most plentiful substances of our planet.


Assuntos
Biodegradação Ambiental , Biocombustíveis/microbiologia , Fontes Geradoras de Energia , Etanol/metabolismo , Bactérias , Biomassa , Fungos , Engenharia Genética , Hidrólise , Lignina , Leveduras
16.
Food Microbiol ; 83: 113-121, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31202402

RESUMO

Co-cultivation of brewers' yeast (Saccharomyces cerevisiae) with Cyberlindnera fabianii makes it possible to steer aroma and alcohol levels by changing the inoculation ratio of the two yeasts. A dynamic model was developed based on mono-culture performance of brewers' yeast and C. fabianii in controlled bioreactors with aerated wort as medium, describing growth rate, carbohydrate utilization, ethanol production, maintenance, oxygen consumption and ergosterol biosynthesis/use for cell membrane synthesis (the last one only for brewers' yeast). The parameters were estimated by fitting models to experimental data of both mono-cultivations. To predict the fermentation outcome of brewers' yeast and C. fabianii in co-cultivation, the two models were combined and the same parameter settings were used. The co-cultivation model was experimentally validated for the inoculum ratios 1:10 and 1:100 brewers' yeast over C. fabianii. The use of predictive modelling supported the hypothesis that performance of brewers' yeast in co-cultivation is inhibited by oxygen depletion which is required for the biosynthesis of ergosterol. This dynamic modelling approach and the parameters involved may also be used to predict the performance of brewers' yeast in the co-cultivation with other yeast species and to give guidance to optimize the fermentation outcome.


Assuntos
Técnicas de Cocultura , Fermentação , Interações Microbianas , Saccharomyces cerevisiae/metabolismo , Saccharomycetales/metabolismo , Ergosterol/biossíntese , Etanol/metabolismo , Oxigênio/metabolismo
17.
J Cancer Res Ther ; 15(3): 556-563, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31169220

RESUMO

Background: Several studies have investigated hypopharyngeal cancer (HC) risk in combination with xenobiotic metabolism-related genetic polymorphisms and the burden of alcohol consumption and smoking in European countries but not in East Asian countries. Patients and Methods: This hospital-based case-control study involved 61 male patients with HC and 71 male cancer-free controls. Information on age, body mass index, and alcohol and cigarette consumption was obtained from medical records, a self-completion questionnaire, and a thorough interview by an otolaryngologist. Alcohol dehydrogenase 1B (ADH1B), aldehyde dehydrogenase 2 (ALDH2), cytochrome P450 A1 (CYP1A1) MspI, CYP1A1 Ile462Val, glutathione S-transferase (GST) M1, GSTT1, and GSTP1 gene polymorphisms were determined by polymerase chain reaction-based methods. Univariate and multivariate analyses were performed by adjustment for age by the Mantel-Haenszel method. Results: The burden of alcohol and cigarette consumption significantly increased the risk of HC and showed a synergistic effect. ADH1B*1/*1 (odds ratio [OR] 7.34) and ALDH2 *1/*2 (OR 13.22) were significant risk factors for HC. Individuals with ADH1B*1/*1 or ALDH2 *1/*2 who consumed alcohol were more susceptible to HC. However, polymorphisms of CYP1A1 gene and GSTs were not significant cancer risk factors in patients with HC. Conclusions: ADH1B*1/*1 and ALDH2 *1/*2 were significant risk factors for HC, while polymorphism of CYP1A1 gene and GSTs was not a significant risk factor for HC. These polymorphisms determined the effects of alcohol and cigarette smoke in addition to burden of alcohol and cigarettes intake on the risk of HC.


Assuntos
Neoplasias Hipofaríngeas/epidemiologia , Neoplasias Hipofaríngeas/etiologia , Adulto , Idoso , Álcool Desidrogenase/genética , Álcool Desidrogenase/metabolismo , Consumo de Bebidas Alcoólicas/efeitos adversos , Aldeído-Desidrogenase Mitocondrial/genética , Aldeído-Desidrogenase Mitocondrial/metabolismo , Carcinógenos , Estudos de Casos e Controles , Etanol/metabolismo , Feminino , Genótipo , Humanos , Neoplasias Hipofaríngeas/metabolismo , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo Genético , Medição de Risco , Fatores de Risco , Fumar/efeitos adversos
18.
Carbohydr Polym ; 219: 414-422, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151542

RESUMO

The bioconversion of rice straw into ethanol can alleviate the energy crisis and solve problems related to waste treatment. In this study, the effect of soluble polysaccharides (SPs) produced during rice straw saccharification on the formation of extracellular matrices (EMs) by the yeast Saccharomyces cerevisiae was investigated. SPs were characterized by high-performance liquid chromatography (HPLC) and fourier transform infrared spectroscopy (FT-IR). SPs reduced the inhibition of alcohol dehydrogenase activity by phenolic acids (PAs) and regulated the intracellular redox state, resulting in higher ethanol production. The results of flow cytometry, confocal laser scanning microscopy, and atomic force microscopy indicated that PAs changed microbial morphology and caused damage in microbial cell membranes. The protective effect of SPs against cell membrane damage could be attributed to the synthesis of polysaccharide-dependent extracellular matrix, which maintained cellular integrity even under phenolic acid stress. These findings provide new strategies to improve pretreatment and saccharification processes.


Assuntos
Membrana Celular , Matriz Extracelular , Oryza/química , Extratos Vegetais , Polissacarídeos/farmacologia , Saccharomyces cerevisiae , Álcool Desidrogenase/metabolismo , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , China , Etanol/metabolismo , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Fermentação , Hidrólise , Hidroxibenzoatos/toxicidade , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/química , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo
19.
J Microbiol Biotechnol ; 29(6): 905-912, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31154746

RESUMO

Bioethanol has attracted much attention in recent decades as a sustainable and environmentally friendly alternative energy source. In this study, we compared the production of bioethanol by Candida molischiana and Saccharomyces cerevisiae at different initial concentrations of cellobiose and glucose. The results showed that C. molischiana can utilize both glucose and cellobiose, whereas S. cerevisiae can only utilize glucose. The ethanol yields were 43-51% from different initial concentrations of carbon source. In addition, different concentrations of microcrystalline cellulose (Avicel) were directly converted to ethanol by a combination of Trichoderma reesei and two yeasts. Cellulose was first hydrolyzed by a fully enzymatic saccharification process using T. reesei cellulases, and the reducing sugars and glucose produced during the process were further used as carbon source for bioethanol production by C. molischiana or S. cerevisiae. Sequential culture of T. reesei and two yeasts revealed that C. molischiana was more efficient for bioconversion of sugars to ethanol than S. cerevisiae. When 20 g/l Avicel was used as a carbon source, the maximum reducing sugar, glucose, and ethanol yields were 42%, 26%, and 20%, respectively. The maximum concentrations of reducing sugar, glucose, and ethanol were 10.9, 8.57, and 5.95 g/l, respectively, at 120 h by the combination of T. reesei and C. molischiana from 50 g/l Avicel.


Assuntos
Biocombustíveis , Candida/metabolismo , Celobiose/metabolismo , Celulose/metabolismo , Etanol/metabolismo , Glucose/metabolismo , Saccharomyces cerevisiae/metabolismo , Candida/crescimento & desenvolvimento , Celobiose/química , Celulase/metabolismo , Celulose/química , Proteínas Fúngicas/metabolismo , Glucose/química , Hidrólise , Saccharomyces cerevisiae/crescimento & desenvolvimento , Açúcares/metabolismo , Trichoderma/crescimento & desenvolvimento , Trichoderma/metabolismo
20.
Rev Med Liege ; 74(5-6): 265-267, 2019 May.
Artigo em Francês | MEDLINE | ID: mdl-31206264

RESUMO

Ethanol is rapidly and almost completely absorbed by the digestive tract, mainly in the small intestine. Alcohol is then metabolized mainly in the liver where it is converted into acetaldehyde. Two systems contribute to this metabolization, the predominant alcohol dehydrogenase pathway, and the pathway controlled by the microsomal ethanol oxidizing system (MEOS), which is inducible and is also involved in the metabolism of other drugs. Acetaldehyde is then metabolized to acetate, which largely leaves the liver to be converted into acetyl-CoA in other tissues. Alcohol is oxidized preferentially to other energetic substrates, leading, in turn, to a decrease in oxidation of lipids which are stored in adipose tissue.


Assuntos
Acetaldeído , Etanol , Álcool Desidrogenase , Etanol/metabolismo , Humanos , Fígado/metabolismo , Oxirredução
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