Electrodialysis, an electrochemical membrane technique, was found to prolong and enhance the production of biohydrogen and purified organic acids via the anaerobic fermentation of glucose by Escherichia coli. Through the design of a model electrodialysis medium using cationic buffer, pH was precisely controlled electrokinetically, i.e. by the regulated extraction of ...

The investigation on the self-assembly of polydeoxyadenylic acid (poly(dA)) is of high importance to fully understand its biological function and for the nano-machine application. Using the fluorescence resonance energy transfer (FRET) technique, we report investigations for the self-assembly of adenine oligomers induced by pH and coralyne binding at the single-molecule ...

We purified to homogeneity and characterized a heat stable thioredoxin which catalyzes thiol/disulfide exchange reaction, for the first time from dromedary pancreas. The purification involved heat and acidic treatment (90 °C; pH 2.5), precipitation by ammonium sulphate and ethanol, respectively followed by sequential column chromatography reverse HPLC column, and it resulted ...

4-Vinyl guaiacol (3-methoxy 4-hydroxystyrene) can be obtained by decarboxylation of ferulic acid by the strain Streptomyces setonii ATCC 39116. The formation of this metabolite was favoured by microaerobic conditions and the culture medium employed, increasing progressively the product concentration from 543.3 up to 885.1 mg/l when aeration level was diminished, reaching ...

(R)-2-Hydroxybutyric acid ((R)-2-HBA) is an important building block for azinothricin family of antitumour antibiotics and biodegradable poly(2-hydroxybutyric acid). However, optically active (R)-2-HBA could not be produced through microbial fermentation or chemical synthesis. Several biocatalytic methods have been reported for the production of (R)-2-HBA. Those processes used expensive and scarce substrates ...

We demonstrate the assembly of extremely robust and pH-responsive thin shell LbL microcapsules from silk fibroin counterparts modified with poly(lysine) and poly(glutamic) acid, which are based on biocompatible silk ionomer materials in contrast with usually exploited synthetic polyelectrolytes. The microcapsules are extremely stable in an unusually wide pH range from ...

Gastroesophageal reflux disease is mediated principally by acid. Today, we recognise reflux reaches beyond the esophagus, where pepsin, not acid, causes damage. Extraesophageal reflux occurs both as liquid and probably aerosol, the latter with a further reach. Pepsin is stable up to pH 7 and regains activity after reacidification. The ...

As wild felids are obligate carnivores, it is likely that poorly enzymatically digestible animal tissues determine hindgut fermentation, instead of plant fibre. Therefore, faecal concentrations of short-chain fatty acids (SCFA, including branched-chain fatty acids, BCFA), indole and phenol were evaluated in 14 captive cheetahs, fed two different diets differing in ...

Frozen par-fried French fries are finish-fried either by using the same type of oil used for par frying, or a different type. The nutritive quality of the final oil contained in the product depends on the relative amounts and the fatty acid (FA) composition of the oils used for par ...

We have previously reported that optimization of a series of phenylacetic acid derivatives led to the discovery of CRTH2 and DP dual antagonists, such as AMG 009 and AMG 853. During the optimization process, we discovered that minor structural modifications also afforded potent and selective CRTH2 or DP antagonists. Here ...

HdeA protein is a small, ATP-independent, acid stress chaperone that undergoes a dimer-to-monomer transition in acidic environments. The HdeA monomer binds a broad range of proteins to prevent their acid-induced aggregation. To understand better HdeA's function and mechanism, we perform constant-pH molecular dynamics simulations (CPHMD) to elucidate the details of ...

Propionic acid, an enteric bacterial fermentation product, has received recent attention in regards to satiety and obesity in humans. The possibility that propionic acid might produce internal aversive cues was investigated in two experiments using conditioned taste avoidance and place avoidance procedures to index the potential aversive nature of systemic ...

A novel codrug (LMX) was obtained from lamivudine (LMV) and ursolic acid (UA) coupled with ethyl chloroacetate through an amide and ester linkage. The structure of LMX was confirmed by (1)H NMR, (13)C NMR, IR and HRMS. Herein, the in vitro non-enzymatic and enzymatic hydrolysis and in vivo pharmacological activities ...

The objective of this study was to investigate the effect of vehicle systems, pH and enhancers on the permeation of a highly lipophilic basic drug aripiprazole (ARPZ) through human cadaver skin. Solubility of ARPZ in single, binary, tertiary, and quaternary vehicle systems of N-methyl pyrrolidone (NMP), dimethyl sulfoxide (DMSO), water, ...

Lactic acid, an attractive, renewable chemical for production of biobased plastics (polylactic acid, PLA), is currently commercially produced from food-based sources of sugar. Pure optical isomers of lactate needed for PLA are typically produced by microbial fermentation of sugars at temperatures below 40 °C. Bacillus coagulans produces L(+)-lactate as a primary ...

Stevia, as animal feed additive, has been researched into over the years, but how to rapidly predict its amino acids contents is yet to be studied. In the present study, 301 samples of stevia leaf powder were defined as the calibration set from which calibration models were optimized and the ...

Urea in alcoholic beverages is a precursor of ethyl carbamate, which is carcinogenic. Acid urease (EC 3.5.1.5) is regarded as a good approach to scavenge the urea. The acid urease of Enterobacter sp. R-SYB082, with lower optimum pH than the widely used commercial acid urease, exhibited a urea removal rate ...

Allyl isothiocyanate (AITC) is a well-recognized antimicrobial agent but, application of AITC to food systems is limited due to its high volatility and strong odor. This study was performed to overcome the volatility of AITC by encapsulation using gum Arabic and chitosan and to investigate the effect of microencapsulated AITC ...

We employ high performance liquid chromatography with diode array, evaporative light scattering and mass spectrometric detection to monitor the oligomerization of L-lactic acid in pure acetonitrile and in 70% aqueous ethanol. The production of higher oligomers appears to proceed in an oscillatory fashion. A model is presented that involves the ...

The CR@BaSO(4) hybrid was synthesized, characterized and used as an acid rain-indicating (ARI) material. A painted ARI umbrella was discolored after exposure to simulated acid rain of pH 5 or less and returned to the initial color after the rain stopped. Such a functionalized material may make acid rain visual ...

ABSTRACT: BACKGROUND: Phospholipase D (PLD) belongs to a lipolytic enzyme subclass which catalyzes the hydrolysis and transesterification of glycerophospholipids at the terminal phosphodiester bond. RESULTS: In this work, we have studied the substrate specificity of PLDs from germinating sunflower seeds and cultured-soybean cells, using their capacity of transphosphatidylation. In the ...

  The aim of this work was to study the influence of nitrogen compounds on the formation of volatile compounds during the alcoholic fermentation carried out with 4 nonaromatic grape varieties collected at 2 different maturation stages. To do this, Monastrell, Merlot, Syrah, and Petit Verdot grapes were collected 1 ...

In the present study, sufu, a soft cheese-like oriental fermented food, was prepared by ripening the salted-tofu cubes in Aspergillus oryzae-fermented soybean-rice koji at 37°C for 16days (16-day sufu). Sufu was further held at room temperature for another 30days (46-day sufu). The volatile components of the non-fermented tofu cubes and ...

Substantial evidence describes the protective effects of marine-derived omega-3 (n-3) polyunsaturated fatty acids (PUFA) on cardiovascular diseases as well as many other conditions. Numerous fatty acid preparations are marketed for supplementing the Western diet, which is low in n-3 fats. Since these preparations may vary in their n-3 PUFA content, ...

Biotechnologically produced succinic acid has the potential to displace maleic acid and its uses. Therefore, it is of high interest for the chemical, pharmaceutical, and food industry.In addition to optimized production strains and fermentation processes, an efficient separation of succinic acid from the aqueous fermentation broth is indispensable to compete ...

Four commercially-available fruit smoothie drinks were assessed for both initial/baseline pH and titratable acidity. A commercially-available smooth orange juice drink was used as a positive control. Baseline pH and titratable acidity were measured by titrating each fruit smoothie with 0.5 mL increments of 1M sodium hydroxide (NaOH), and measuring the ...

ABSTRACT: BACKGROUND: Succinic acid is a building-block chemical which could be used as the precursor of many industrial products. The dissolved CO2 concentration in the fermentation broth could strongly regulate the metabolic flux of carbon and the activity of phosphoenolpyruvate (PEP) carboxykinase, which are the important committed steps for the ...

Ethanol alters the function of several members of the Cys-loop ligand-gated ion channel superfamily. Recent studies have shown that the sensitivity of the α1 glycine receptor (GlyR) to ethanol can be affected by the state of G protein activation mediated by the interaction of Gβγ with intracellular amino acids in ...

Continuous in situ generation of phosgene and its use in acid chloride formation in a microflow system were demonstrated. The acid chloride was subsequently coupled with an amine in high yield without severe epimerization.

In vitro batch incubations were used to study the rumen biohydrogenation of unsaturated fatty acids. An earlier study using increasing supplementation levels of stearidonic acid (18:4n-3), revealed that the rumen microbial population extensively biohydrogenates 18:4n-3 after 72 h of in vitro incubation, though several intermediates formed were not completely characterized. Therefore, ...

Misgurin is an antimicrobial peptide from the loach, while the hydrophobic-polar (HP) model is a way to study the folding conformations and native states in peptide and protein although several amino acids cannot be classified either hydrophobic or polar. Practically, the HP model requires extremely intensive computations, thus it has ...

The β-mannanase gene, man5C1, was cloned from Penicillium pinophilum C1, a strain isolated from the acidic wastewater of a tin mine in Yunnan, China, and expressed in Pichia pastoris. The sequence analysis displayed the gene consists of a 1221-bp open reading frame encoding a protein of 406 amino acids (Man5C1). ...

Effects of Ca(OH)(2), NH(4)OH, and NaOH as neutralizing agents for efficient recovery of lactic acid was investigated. Lactic acid was produced from broken rice in a simultaneous saccharification and fermentation (SSF) process with Lactobacillus delbrueckii. Consumption of glucose (from broken rice) by the cells and the cell growth were the ...

In this study, the effects of pH, bromide and nitrite on the formation of halonitromethanes (HNMs) and trihalomethanes (THMs) from eight amino acids (glycine, alanine, serine, cysteine, aspartic acid, glutamic acid, lysine and histidine) and four amino sugars (glucosamine, galactosamine, N-acetylglucosamine and N-acetylneuraminic acid) were examined for chlorination and ozonation ...

The present work deals with the optimization of cellular disruption and sugar extraction from the microalgae Scenedesmusobliquus (Sc) for bioethanol production. Among the physical and physicochemical methods tested, the best results were obtained with acid hydrolysis by H(2)SO(4) (2N), at 120°C for 30min and using dried biomass. The sugar extraction ...

A new type of in situ product removal (ISPR) technique of expanded bed adsorption (EBA) bioreactor was studied to simultaneously produce extracellular propionic acid and intracellular vitamin B12 by Propionibacterium freudenreichii CICC 10019. Resin screening experiments showed that the ZGA330 resin have the best biocompatibility and highest adsorption for propionic ...

The synthesis and characterization of organic-inorganic hybrid materials that selectively capture sugars from model biomass hydrolysis mixtures are reported. 3-Aminophenylboronic acid (PBA) groups that can reversibly form cyclic esters with 1,2-diols and 1,3-diols including sugars are attached to mesoporous SBA-15 via different synthetic protocols. In the first route, a coupling ...

Dietary supplementation of stearidonic acid (SDA; 18:4n-3) has been considered to be a possible strategy to increase n-3 unsaturated fatty acid content in ruminant products, however little is known about its metabolism in the rumen. In vitro batch incubations were carried out with bovine ruminal digesta to investigate the metabolism ...

The effects of (14)C-labelled precursor feeding on the production of cyclic hexadepsipeptides were investigated by the mycelium of F. oxysporum KFCC11363P producing beauvericin along with enniatins H, I, and MK1688. Most (14)C-phenylalanine and (14)C-valine were incorporated easily into the biosynthetic pathway of (14)C-labelled beauvericin in vivo by the mycelium. However, ...

Alginate is a natural acidic linear polysaccharide that is produced by brown seaweeds. It is currently used in a broad range of commercial enterprises, such as the food and medical products industries. Recent evidence has demonstrated that alginate oligosaccharides may function as growth promoting agents for certain plant cells, including ...

PURPOSE: The use of recombinant human interleukin (rhIL)-15 as a potential therapeutic immune modulator and anticancer agent requires pure, stable preparations. However, purified rhIL-15 preparations readily accumulated heterogeneities. We sought to improve rhIL-15 stability through process, formulation, and targeted amino acid changes. METHODS: The solution state of rhIL-15 versus buffer ...

ABSTRACT: BACKGROUND: Teicoplanin is a glycopeptide antibiotic used clinically in Europe and in Japan for the treatment of multi-resistant Gram-positive infections. It is produced by fermenting Actinoplanes teichomyceticus. The pharmaceutically active principle is teicoplanin A2, a complex of compounds designated T-A2-1/A2-2/A2-3/A2-4 and A2-5 differing in the length and branching of ...

BACKGROUND: Quinoa is a good source of protein and can be used as a nutritional ingredient in food products. This study analyses how much growing region and/or seasonal climate might affect grain yield and nutritional quality of quinoa seeds. RESULTS: Seeds of ten quinoa cultivars from the Andean highlands (Bolivia/Argentina ...

Formic acid is a highly energetic electron donor but it has previously resulted in low power densities in microbial fuel cells (MFCs). Three different set anode potentials (-0.30, -0.15, and +0.15 V; vs a standard hydrogen electrode, SHE) were used to evaluate syntrophic interactions in bacterial communities for formic acid degradation ...

The pH value is a fundamental datum to be monitored during marination. A method is proposed for calculating the evolution of pH of turkey meat cubes during marination in an acetic acid solution. It is based on measurement of the buffering capacity by acidification using a strong acid. A calculation ...

A chitosan-glutaraldehyde crosslinked uricase was immobilized onto Prussian blue nanoparticles (PBNPs) absorbed onto carboxylated multiwalled carbon nanotube (c-MWCNT) and polyaniline (PANI) layer, electrochemically deposited on the surface of Au electrode. The nanohybrid-uricase electrode was characterized by scanning electron microscopic (SEM), Fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry. An amperometric ...

A neutralizing agent combination strategy was developed to enhance the succinic acid production by Actinobacillus succinogenes ATCC 55618. First, a maximal succinic acid production of 48.2 g/L was obtained at a culture pH of 7.5. Second, NaOH and KOH were screened to identify the optimal neutralizing agent for pH control. However, ...

A short and effective synthesis of ethyl 3-(3-aminophenyl)propanoate is presented, employing a tandem Knoevenagel condensation/alkylidene reduction of 3-nitrobenzaldehyde with Meldrum's acid in TEAF (triethylammonium formate) followed by reduction of the intermediate 3-(3-nitrophenyl)propanoic acid by stannous chloride in ethanol. The use of stannous chloride as the reducing agent in ethanol enabled ...

As energy and environment have become urgent issues, there has been increasing needs to develop alternative energy source, such as microalgal bio-fuel. In this study, we investigated the growth and lipid contents of microalgae Nannochloris oculata under various environmental conditions for biodiesel production. Our results indicated that biomass productivities of ...

The effects of exposure concentration on the bioaccumulation of four perfluorinated chemicals (PFCs): perfluorooctanesulfonate (PFOS), perfluoroocanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA), was investigated using green mussels, Perna viridis. Mussels were exposed to concentrations of 1 μgL(-1) and 10 μgL(-1) of each PFC for 56 days, and ...