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... Ethanol-stressed cultures of Z. mobilis showed greatly reduced lag times in growth when supplemented with small amounts of acetaldehyde. This effect could be mimicked by other metabolic electron acceptors, including propionaldehyde and oxygen, indicating a redox-based mechanism. Added propionaldehyde was rapidly and stoichiometrically converted to 1-propanol, suggesting that added acetaldehyde is ...
... The yeast (Saccharomyces cerevisiae) strain 2137 involved in lychee wine production was used to investigate acetate metabolism at different temperatures during lychee wine fermentation. Fermentation tests were conducted using lychee juice supplemented with acetic acid. The ability of yeast cells to metabolize acetic acid was stronger at 20 °C than at 25 °C or 30 °C. The addition of acetic acid sup ...
... Acetyl‐coenzyme A (acetyl‐CoA) is a key molecule that participates in many biochemical reactions in amino acid, protein, carbohydrate and lipid metabolism. Here, we genetically dissected the distinct roles of two acetyl‐CoA synthetase genes, ChAcs1 and ChAcs2, in the regulation of fermentation, lipid metabolism and virulence of the hemibiotrophic fungus Colletotrichum higginsianum. ChAcs1 and ChAc ...
... Acetobacterium woodii utilizes the Wood‐Ljungdahl pathway for reductive synthesis of acetate from carbon dioxide. However, A. woodii can also perform non‐acetogenic growth on 1,2‐propanediol (1,2‐PD) where instead of acetate, equal amounts of propionate and propanol are produced as metabolic end products. Metabolism of 1,2‐PD occurs via encapsulated metabolic enzymes within large proteinaceous bod ...
acetaldehyde; acetates; acetone; active sites; adsorption; air pollutants; air pollution; catalysts; energy; methodology; models; moieties; titanium dioxide; volatile organic compounds
Abstract:
... The carbonyl-containing compounds (CCs) are typical volatile organic compounds (VOCs) and ubiquitously present in the environment. Therefore, the adsorption structures and properties of typical CCs on the anatase TiO₂ (001) surface were investigated systematically with density functional theory (DFT) to understand their further catalytic degradation mechanisms. The adsorption mechanisms show that ...
... Benefits and harms of different components of human diet have been known for hundreds of years. Alcohol is one the highest consumed, abused, and addictive substances worldwide. Consequences of alcohol abuse are increased risks for diseases of the cardiovascular system, liver, and nervous system, as well as reduced immune system function. Paradoxically, alcohol has also been a consistent protective ...
... Previous studies have shown that the metabolic capability of colonic microflora may be at least as high as that of the liver or higher than that of the whole human body. Aldehyde dehydrogenase (ALDH) is an enzyme produced by these bacteria that can metabolize acetaldehyde, produce from ethanol to acetate. Lactococcus species, which is commonly used as a starter in dairy products, was recently foun ...
... Glycerol formation is vital for reoxidation of nicotinamide adenine dinucleotide (reduced form; NADH) under anaerobic conditions and for the hyperosmotic stress response in the yeast Saccharomyces cerevisiae. However, relatively few studies have been made on hyperosmotic stress under anaerobic conditions. To study the combined effect of salt stress and anaerobic conditions, industrial and laborato ...
... In Hevea brasiliensis, the laticifers, a green factory of natural rubber, are specialised vessels in which rubber biosynthesis is the main metabolism, and fresh rubber occupies 35–45% volume of latex (the cytoplasm of laticifers). Intriguingly, Latex can be reproduced, drawing on three essential components (i.e., ATP, Acetyl-CoA and NADPH) from glycolysis in laticifers during tapping (a simple col ...
... The chemical composition of several commercial Italian Limoncellos, lemon-peel-based alcoholic beverages, was studied by chromatographic techniques. These methods allowed a rapid monitoring of Limoncello, giving information on quality markers and possible adulteration of the product. Quantitative data for more than 60 compounds are reported. Limoncellos were characterized by the presence of select ...
... This review summarises the current state of knowledge on the biodegradation and fate of the gasoline ether oxygenate ethyl tert-butyl ether (ETBE) in soil and groundwater. Microorganisms have been identified in soil and groundwater with the ability to degrade ETBE aerobically as a carbon and energy source, or via cometabolism using alkanes as growth substrates. Aerobic biodegradation of ETBE initi ...
... The production of butyl and hexyl acetates and the contents of ethanol and acetaldehyde in relation to the activity of some related enzymes (lipoxygenase, pyruvate decarboxylase, alcohol dehydrogenase and alcohol o-acyltransferase) was studied in ‘Doyenne du Comice’ pears during ripening at 20 °C, following long-term cold storage under different conditions: air, or CA in 2 kPa O(2) with various CO ...
... Pyruvate is the key substance controlling the formation of diacetyl, acetaldehyde, and acetate during alcoholic fermentation. Here we report the breeding of a low pyruvate-producing sake yeast by isolation of a mutant resistant to ethyl α-transcyanocinnamate, an inhibitor of mitochondrial pyruvate transport. Mitochondrial function was involved in resistance to this substance and in the production ...
... This work presents the application of a differential distillation model for the simulation of cachaça production in a pot still (alembic). The vapor-liquid equilibria of the multicomponent mixture were described in a rigorous way, using the nonrandom two-liquid model for the liquid phase activity coefficients and the virial equation with the chemical theory for the vapor phase fugacity coefficient ...
... Coal-fire gas jets emanating from waste heaps are chemically very complex and variable mixtures, as proved by our former studies. The current paper is a result of further exploration of the GASMET FTIR system via an iterative external databases search. This allowed to pinpoint a number of subsequent chemicals, both in terms of (semi)quantitative analysis and occurrence probability (fit). Some comp ...
... BACKGROUND: The C. bescii genome does not encode an acetaldehyde/alcohol dehydrogenase or an acetaldehyde dehydrogenase and no ethanol production is detected in this strain. The recent introduction of an NADH-dependent AdhE from C. thermocellum (Fig. 1a) in an ldh mutant of this strain resulted in production of ethanol from un-pretreated switchgrass, but the thermolability of the C. thermocellum A ...
... Hamlin, Pineapple and Valencia oranges were stored in controlled atmospheres (CA) of nitrogen, carbon dioxide or 0.1–0.7% acetaldehyde in air 8–24 hours and changes in seven volatiles during 0–8 days determined by gas chromatography. Increases in acetaldehyde, ehtyl acetate, ethyl butyrate and ethanol were noted in samples after nitrogen or carbon dioxide CA storage with maximum increase 1–2 days ...
... Acetobacter aceti NBRC 14818 shows a diauxic growth profile and temporarily accumulates acetate when grown in medium containing ethanol. However, the mechanisms underlying the metabolic switching between the incomplete oxidation of ethanol and overoxidation of acetate, and the control of stress resistance systems in A. aceti cells grown on ethanol are not fully understood. In this study, time-depe ...
... The study was carried out to analyse volatile compounds (VOCs) associated to sensory changes during the storage of traditional sorghum beer at ambient temperature and 4 °C. Tchapalo samples were collected and stored at ambient temperature (27–30 °C) for four days and at 4 °C for six days. Volatile and sensory changes were monitored during the storage period. VOCs were extracted and detected using ...
... In this study, two pyridine-degrading strains namely Enterobacter cloacae complex sp. BD17 and Enterobacter sp.BD19 were isolated from the aerobic tank of a pesticide wastewater treatment plant. The mixed bacteria H4 composed of BD17 and BD19 at a ratio of 1:1 was immobilized by Solidago canadensis L. stem biochar with a dosage of 2 g·L⁻¹. The highest pyridine removal rate of 91.70% was achieved b ...
... Application of aroma extract dilution analysis (AEDA) on the volatiles isolated from a commercial Bavarian wheat beer (WB A) eliciting its typical aroma profile, best described by a clove-like, phenolic odor quality, revealed 36 odorants in the flavor dilution (FD) factor range from 16 to 4096. Among them, 2-methoxy-4-vinylphenol (clove-like) and 2-phenylethanol (flowery) showed the highest FD fac ...
... The aroma profiles of Spanish wine vinegars with Protected Designation of Origin (PDO) were described and compared for the first time by gas chromatography–mass spectrometry–olfactometry (GC–MS–O), odor-active values (OAVs) and quantitative descriptive analysis (QDA). Vinagre de Jerez Reserva (JRE) showed higher percentage of ‘grassy-vegetal’ impact odorants, while ‘spicy’ compounds highlighted th ...
... Aims: This study was designed to gain knowledge of three Controlled Denomination of Origin (DOC) Italian sweet white Passito wines (Caluso Passito DOC, Cinque Terre Sciacchetrà DOC and Passito di Pantelleria DOC) produced in several areas of Italy from grapes dried with different systems and vinification techniques. Methods and results: Physico-chemical and chromatic characteristics, sodium, potas ...
Magalhães, Karina Teixeira; Dias, Disney Ribeiro; de Melo Pereira, Gilberto Vinicius; Oliveira, José Maria; Domingues, Lucília; Teixeira, José António; de Almeida e Silva, João Batista; Schwan, Rosane Freitas
... The aim of the present work was to evaluate the use of the kefir grains as a starter culture for tradicional milk kefir beverage and for cheese whey-based beverages production. Fermentation was performed by inoculating kefir grains in milk (ML), cheese whey (CW) and deproteinised cheese whey (DCW). Erlenmeyers containing kefir grains and different substrates were statically incubated for 72 h at 2 ...
... In the context of algal wastewater bioremediation, this study has identified a novel consortium formed by the bacterium Methylobacterium oryzae and the microalga Chlamydomonas reinhardtii that greatly increase biomass generation (1.22 g L⁻¹·d⁻¹), inorganic nitrogen removal (>99%), and hydrogen production (33 mL·L⁻¹) when incubated in media containing ethanol and methanol. The key metabolic aspect ...
... Acetic acid decomposition on Pd(100) and Pd/Au(100) during vinyl acetate (VA) synthesis from ethylene acetoxylation is the primary source of such undesirable byproducts as methanol (CH₃OH), acetaldehyde (CH₃CHO), ketene (CH₂CO), acetone (CH₃COCH₃), and methane (CH₄), and also one possible source of surface carbon formation, which will lead to the deactivation of the catalyst. In this work, density ...
... We compared the volatile profiles in soy sauce according to inoculation with Tetragenococcus halophilus and/or Zygosaccharomyces rouxii. Totals of 107 and 81 volatiles were respectively identified by using solid-phase microextraction and solvent extraction. The various volatile compounds identified included acids, aldehydes, esters, ketones, furans and furan derivatives, and phenols. The major vol ...
... Tomato (Lycopersicon esculentum Mill.) is an important vegetable crop cherished all over the world for consumption as a raw vegetable or as processed products. They are subjected to various drying processes to increase product stability and decrease postharvest loss. However, this can cause a loss in volatile compounds due to process conditions. Present study aims to gain an insight into the volat ...
Karina T. Magalhães; Giuliano Dragone; Gilberto V. de Melo Pereira; José M. Oliveira; Lucília Domingues; José A. Teixeira; João B. Almeida e Silva; Rosane F. Schwan
... Cheese whey (CW) and deproteinised cheese whey (DCW) were investigated for their suitability as novel substrates for the production of kefir-like beverages. Lactose consumption, ethanol production, as well as organic acids and volatile compounds formation, were determined during CW and DCW fermentation by kefir grains and compared with values obtained during the production of traditional milk kefi ...
... The influence of two systems of aging (traditional and alternative) on the chemical composition of cider brandy was compared. The traditional system consisted in classical aging in barrels while the alternative method consisted in aging in stainless steel vessels with staves and micro-oxygenation. Three types of oak wood were used: American, French and Spanish. Treatment with micro-oxygenation acc ...
... Consumption and production of pomegranate fruit and juice have been increasing. Many pomegranate volatile reports involved commercial samples, complicated isolation methods, or different cultivars. In this study, three different techniques including simultaneous distillation extraction (SDE), headspace solid-phase micro-extraction (HS-SPME), and purge and trap (P&T) with Tenax TA absorbent were em ...
... Acetogen strain Clostridium sp. MT1121 produced 300 mM acetate (p < 0.005) and 321 mM ethanol (p < 0.005) from synthesis gas (syngas) blend 60 % CO and 40 % H₂. Clostridium sp. MT1121 was metabolically engineered to eliminate production of either acetate or acetaldehyde during syngas fermentation. We used Cre-lox66/lox71-based gene removal system to eliminate either phosphotransacetylase (pta), or ...
... Clostridium formicoaceticum, a Gram-negative mixotrophic homoacetogen, produces acetic acid as the sole metabolic product from various carbon sources, including fructose, glycerol, formate, and CO2. Its genome of 4.59-Mbp contains a highly conserved Wood-Ljungdahl pathway gene cluster with the same layout as that in other mixotrophic acetogens, including Clostridium aceticum, Clostridium carboxidi ...
... Gluconobacter oxydans, a biotechnologically relevant species which incompletely oxidizes a large variety of carbohydrates, alcohols, and related compounds, contains a gene for pyruvate decarboxylase (PDC). This enzyme is found only in very few species of bacteria where it is normally involved in anaerobic ethanol formation via acetaldehyde. In order to clarify the role of PDC in the strictly oxida ...
orchards; fermentation; insect pests; acetates; peaches; insect attractants; volatile organic compounds; acetaldehyde; Prunus persica; Carpophilus; field experimentation; insect control; fruit juices; ethanol; Victoria (Australia)
Abstract:
... An effective synthetic attractant, based on host-related volatile compounds, was developed for the nitidulid beetle, Carpophilus davidsoni, as part of a program for managing this pest in Australian peach orchards. Fermenting peach juice and whole peaches and nectarines served as chemical models for the attractant, and synthetic formulations were sought that matched the natural sources, both with r ...
acetaldehyde; acetates; apple juice; flavor compounds; gas chromatography; headspace analysis; juice quality; mass spectrometry; odor compounds; odors; sensory evaluation
Abstract:
... A reliable and simple method was developed for the completely automatised analysis of apple juice aroma compounds. In total 26 flavour compounds could be measured by headspace trap gas chromatography/mass spectrometry (GC/MS). We used the method to analyse 85 commercially available apple juices, of which 67 apple juices were not from concentrate. Our results show that apple juices not from concent ...
... Ethanol is the most widely used renewable transportation biofuel in the United States, with the production of 13.3 billion gallons in 2012 [John UM (2013) Contribution of the Ethanol Industry to the Economy of the United States ]. Despite considerable effort to produce fuels from lignocellulosic biomass, chemical pretreatment and the addition of saccharolytic enzymes before microbial bioconversion ...
... The adsorption and decomposition of acetaldehyde and acetic acid were studied on Rh(100) to gain insight into the interaction of aldehyde and carboxyl groups of biomass-derived molecules with the surface. Temperature-programmed reaction spectroscopy (TPRS) was used to monitor gaseous reaction products, whereas Reflection absorption infrared spectroscopy (RAIRS) was used to determine the nature of ...
... With both real-world catalyst Rh/CeO₂ and model-system Rh(111), we investigated how oxygen and water play effective roles in the oxidative steam-reforming (OSR) reaction of ethanol. The results show that atomic oxygen (O*) on Rh surfaces enhanced significantly the decomposition probability of ethanol and altered the reaction path from one via cleavage of the C–Hᵦ bond forming an oxametallacycle to ...
... The concentrations of amino acids and volatile compounds of a given grapevine cultivar may be modified by climate variability between years and by management practices, such as irrigation, that may alter the typicality of its wines. The current study aimed at assessing the amino acid profile of musts and wines, volatile composition and sensory profile of wines from Vitis vinifera (L.) cultivar God ...
... Strawberry fruit and western flower thrips were exposed to 1, 2, 3, or 4% acetaldehyde (Aa) for 2 h in air or in 20 kPa CO2. Following treatment, fruit were stored at 0 or 20 °C for 4 or 2 days, respectively. Aa treatment did not significantly impact fruit firmness, color, or soluble solids content; however, calyx damage increased with increasing concentration of Aa. Strawberry fruit tolerated exp ...
... Herein, we report the influence of different combinations of initial concentration of acetic acid and ethanol on the removal of acetic acid from acidic wines by two commercial Saccharomyces cerevisiae strains S26 and S29. Both strains reduced the volatile acidity of an acidic wine (1.0 g l⁻¹ acetic acid and 11% (v/v) ethanol) by 78% and 48%, respectively. Acetic acid removal by strains S26 and S29 ...
... Background and aims: Wine is a beverage characterized by its pleasant aromatic features. These sensory notes are determined by the specific concentrations of odorous chemical compounds in each wine. Many of these aroma compounds arise directly or indirectly from the grapes, and their formation is affected by both grape metabolism and the viticultural ecosystem. Two studies were done with the 2015 ...
... Montepulciano grapes were dehydrated at 10 and 20°C, 45% RH and 1-1.5m/s of air flow. Samplings were performed at 10%, 20%, 30%, and 40% of weight loss (wl). TSS (total solids content) increased up to 43° and 36° Brix at 20 and 10°C, respectively, in 27 and 48days. A straight regression line between M (kg water/kg dry matter) loss and days of dehydration with R ² values, equal to 0.97, was found b ...
... In anaerobic cultures of wild-type Saccharomyces cerevisiae, glycerol production is essential to reoxidize NADH produced in biosynthetic processes. Consequently, glycerol is a major by-product during anaerobic production of ethanol by S. cerevisiae, the single largest fermentation process in industrial biotechnology. The present study investigates the possibility of completely eliminating glycerol ...
... Esterases are widely used in food processing industry, but there is little information concerning enzymes involved in decompositions of esters contributing to pollution of environment. Vinyl acetate (an ester of vinyl alcohol and acetic acid) is a representative of volatile organic compounds (VOCs) in decomposition, of which hydrolyses and oxidoreductases are mainly involved. Their activities unde ...
... Given its availability and low price, glycerol has become an ideal feedstock for the production of fuels and chemicals. We recently reported the pathways mediating the metabolism of glycerol in Escherichia coli under anaerobic and microaerobic conditions. In this work, we engineer E. coli for the efficient conversion of glycerol to D-lactic acid (D-lactate), a negligible product of glycerol metabo ...
... The application of microorganisms to control the growth of foodborne pathogens is an alternative to the use of chemical additives. In this work, Pseudomonas graminis CPA-7 was tested as a biocontrol agent against Salmonella enterica and Listeria monocytogenes on fresh-cut pear under conditions that simulate its commercial application at 5 ± 1 °C (under a modified atmosphere and antioxidant solutio ...
... cis-2-Methyl-4-propyl-1,3-oxathiane (cis-2-MPO) was recently identified in wine and proposed to arise from the reaction of 3-sulfanylhexan-1-ol (3-SH) and acetaldehyde. However, the evolution profile of cis-2-MPO during alcoholic fermentation (AF) and storage and its relationship with varietal thiols and acetaldehyde production were unknown. These aspects were investigated by fermenting Sauvignon ...
... The evolution during ripening and the seasonal variation of the volatile fraction of Zamorano cheeses were studied by using purge and trap extraction and GC-MS analysis. Concentrations of acetaldehyde, propanal and branched chain aldehydes, 2-methyl ketones, higher molecular weight alcohols, and most esters increased significantly with ripening time. Branched chain aldehydes were more abundant in ...