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Results 201 - 250 of 2340
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Vera Annabelle - - 2011
Sourdoughs are complex ecosystems which are widely used to produce baked goods. This study aimed to provide a dynamic description of an industrial French sourdough ecosystem over 10 consecutive days. The sourdough was obtained from a natural fermentation that has been propagated over several years by the traditional backslopping method. ...
Zhang Yali - - 2011
Clostridium tyrobutyricum ATCC 25755 is an anaerobic, rod-shaped, gram-positive bacterium that produces butyrate, acetate, hydrogen, and carbon dioxide from various saccharides, including glucose and xylose. Phosphotransbutyrylase (PTB) is a key enzyme in the butyric acid synthesis pathway. In this work, effects of ptb knockout by homologous recombination on metabolic flux ...
Wu Shuqi - - 2011
Alteration of lysosome acidity has been implicated in many biological events ranging from apoptosis to cancer metastasis, etc. Mesoporous silica nanoparticles doped with acid activable rhodamine-lactam and fluorescein isothiocyanate (FITC) were developed for ratiometric sensing of lysosomal pH changes in live cells with flow cytometry.
Vlahov Iontcho R - - 2011
Tubuylsins are extremely potent cytotoxic agents which inhibit tubulin polymerization and lead to cell cycle arrest and apoptosis. Tubulysins have been isolated from fermentation mixtures and have been chemically synthesized; however, these efforts have been hampered by poor yields and arduous purifications. In contrast, treatment of a mixture of natural ...
Papalexandratou Zoi - - 2011
Traditional fermentations of the local Ecuadorian cocoa type Nacional, with its fine flavor, are carried out in boxes and on platforms for a short time. A multiphasic approach, encompassing culture-dependent and -independent microbiological analyses of fermenting cocoa pulp-bean samples, metabolite target analyses of both cocoa pulp and beans, and sensory ...
Song Jiaxiu - - 2011
The microbial structure and kinetic characteristics of the hydrogen producing strains in two fermentative continuous stirred-tank reactors (CSTRs) were studied by controlling pH and oxidation and reduction potential (ORP). The fluorescence in situ hybridization (FISH) tests were conducted to investigate the fermentative performance of Clostridium histolyticum (C. histolyticum), Clostridium lituseburense ...
Ye Zhixia - - 2011
Understanding protein-protein interactions that occur between ACP and KS domains of polyketide synthases and fatty acid synthases is critical to improving the scope and efficiency of combinatorial biosynthesis efforts aimed at producing non-natural polyketides. Here, we report a facile strategy for rapidly reporting such ACP-KS interactions based on the incorporation ...
Hernandez-Hernandez Oswaldo - - 2011
In this work, in vitro fermentation of alternansucrase raffinose derived oligosaccharides, previously fractionated according to their degree of polymerization (DP; from DP4 to DP10) was carried out using small-scale pH-controlled batch cultures at 37 ºC under anaerobic conditions with human feces. Bifidogenic activity of oligosaccharides with DP4-6 similar to that ...
Sun Jingxian - - 2011
This study evaluated the influences of inoculum-substrate ratio (ISR), volatile fatty acids (VFAs) and nicotinamide adenine dinucleotide, the reduced form (NADH) on hydrogen production during the anaerobic fermentation of Chlorella sp. in batch tests at 35°C. The results indicated that the hydrogen concentration and lag time increased when ISR decreased, ...
Ramnani Priya - - 2011
Fermentation properties and prebiotic potential of novel low molecular weight polysaccharides (LMWPs) derived from agar and alginate bearing seaweeds was investigated. Ten LMWPs were supplemented to pH, temperature controlled anaerobic batch cultures inoculated with human feces from three donors, in triplicate. Microbiota changes were monitored using Fluorescent in-situ hybridization and ...
Bellido Carolina - - 2011
The inhibitory effect of the main inhibitors (acetic acid, furfural and 5-hydroxymethylfurfural) formed during steam explosion of wheat straw was studied through ethanol fermentations of model substrates and hydrolysates from wheat straw by Pichia stipitis. Experimental results showed that an increase in acetic acid concentration led to a reduction in ...
Golub Kristina W - - 2011
Countercurrent fermentation is a high performing process design for mixed-acid fermentation. However, there are high operating costs associated with moving solids, which is an integral component of this configuration. This study investigated the effect of volatile solid loading rate (VSLR) and agitation in propagated fixed-bed fermentation, a configuration which may ...
Madeira Jose Valdo JV - - 2011
The production of enzymes such as tannases and phytases by solid-state fermentation and their use in animal feed have become a subject of great interest. In the present work, Paecilomyces variotii was used to produce tannase and phytase simultaneously. Solid-state fermentation, a process initially designed for tannase production, was implemented ...
Meinita Maria Dyah Nur - - 2011
Red seaweed, Kappaphycus alvarezii, holds great promise for use in biofuel production due to its high carbohydrate content. In this study, we investigated the effect of fermentation inhibitors to the K. alvarezii hydrolysate on cell growth and ethanol fermentation. In addition, detoxification of fermentation inhibitors was performed to decrease the ...
Meinita Maria Dyah Nur - - 2011
In this study, hydrolysis of marine algal biomass Kappaphhycus alvarezii using two different acid catalysts was examined with the goal of identifying optimal reaction conditions for the formation of sugars and by-products. K. alvarezii were hydrolyzed by autoclave using sulfuric acid or hydrochloric acid as catalyst with different acid concentrations ...
Vergara-Barberán María - - 2011
A method for the determination of fatty acids in vegetable oils by capillary electrophoresis with indirect UV-Vis detection has been developed. The separation of fatty acids was optimized in terms of Brij surfactant nature and concentration, and organic modifier (2-propanol) percentage. The optimal background electrolyte consisted of a 10 mM ...
Berezina Nathalie - - 2011
In the current context of global warming, the substitution of conventional plastics with bioplastics is a challenge. To take it up we must meet technical and financial requirements. In the case of PHBV, technical properties' modulation can be acquired via 3-hydroxyvalerate content modification. Yet 3-hydroxyvalerate enhancement is an issue; simultaneous ...
Lee Vivian Chi Yan - - 2011
BACKGROUNDThe pharmacokinetics of vaginal misoprostol as a dry tablet or as a tablet moistened with normal saline or with acetic acid were studied.METHODSFor this study, 42 women requesting termination of pregnancy at gestational age of <12 weeks were recruited and received 400 µg vaginal misoprostol tablets. They were randomized into ...
Neilands J - - 2011
In this study we evaluated the effect of chitosan nanoparticles on the acid tolerance response (ATR) of adhered Streptococcus mutans. An ATR was induced by exposing S. mutans to pH 5.5 for 2 h and confirmed by exposing the acid-adapted cells to pH 3.5 for 30 min, with the majority ...
Liu Liming - - 2011
In the two-step fermentative production of vitamin C, its precursor 2-keto-l-gulonic acid (2-KLG) was synthesized by Ketogulonicigenium vulgare through co-culture with Bacillus megaterium. The reconstruction of the amino acid metabolic pathway through completed genome sequence annotation demonstrated that K. vulgare was deficient in one or more key enzymes in the ...
Umakoshi Motoki - - 2011
Corynebacterium glutamicum is known as a host species for amino acid production. This microorganism was recently noticed as a host that produces secreted proteins. In this study, we performed (13)C metabolic flux analysis ((13)C-MFA) on a recombinant C. glutamicum strain that secretes a heterologous transglutaminase (TGase) to improve TGase secretion. ...
Nakata Kenya - - 2011
(R)-(+)-N-Methylbenzoguanidine ((R)-NMBG) was found to function as an efficient acyl-transfer catalyst for the kinetic resolution of racemic secondary benzylic alcohols in the presence of achiral carboxylic acids and pivalic anhydride. The use of a tertiary amine in this reaction is not necessary to attain good chemical yields of the products. ...
Masiak Wioletta - - 2011
The technique of 24-hour esophageal multichannel intraluminal impedance monitoring combined with pH-metry (MII-pH) is currently considered to be the golden standard in the diagnostics of gastroesophageal reflux disease (GERD). The technique allows for differentiation of gas and liquid reflux as well as detection of non-acid reflux, which cannot be detected ...
Ercan D - - 2011
Characterization of traditional cheeses is important for the protection of diversity of tradition and contributing baseline data for further research and quality control. Sepet cheese is a traditional cheese and specific to the Aegean region of Turkey. In this study, 52 Sepet cheese samples were analyzed to characterize the physicochemical, ...
Richter Joel E - - 2011
The following on proton pump inhibitors (PPIs) and chemoprevention in relation to Barrett's esophagus includes commentaries on 48-h pH monitoring, pH-impedence, bile acid testing, dyspepsia, long/short segment Barrett's esophagus, nonerosive reflux disease (NERD), functional heartburn, dual-release delivery PPIs, immediate-release PPIs, long-term PPI use, prokinetic agents, obesity, baclofen, nocturnal acid breakthrough, ...
McIntosh Lawrence P - - 2011
NMR-monitored pH titration curves of proteins provide a rich source of structural and electrostatic information. Although relatively straightforward to measure, interpreting pH-dependent chemical shift changes to obtain site-specific acid dissociation constants (pK (A) values) is challenging. In order to analyze the biphasic titrations exhibited by the side chain (13)C(γ) nuclei ...
Klein C M - - 2011
Pathways of docosahexaenoic (DHA) biohydrogenation are not known; however, DHA is metabolized by ruminal microorganisms. The addition of DHA to the rumen alters the fatty acid profile of the rumen and milk and leads to increased trans-18:1 isomers, particularly trans-11 18:1. This study included 2 in vitro experiments to identify ...
Azócar Laura - - 2011
One major problem in the lipase-catalyzed production of biodiesel or fatty acid methyl esters (FAME) is the high acidity of the product, mainly caused by water presence, which produces parallel hydrolysis and esterification reactions instead of transesterification to FAME. Therefore, the use of reaction medium in absence of water (anhydrous ...
Thiru Meikandhan - - 2011
The objective of the current report is process optimization for economical production of lipids by the well known oleaginous yeast Cryptococcus curvatus and conversion of the lipids to biodiesel. A high cell density fed-batch cultivation on low cost substrate viz. crude glycerol resulted in a dry biomass and oil yield ...
El-Alfy Taha S - - 2011
A chemical study of the red type of the seeds of Eragrostis tef (Zucc.) Trotter (Poaceae) led to the isolation of seven compounds from its ethanol extract, namely β-sitosterol (1), β-amyrin-3-O-(2'-acetyl(glucoside (2), β-sitosterol-3-O-β-D-glucoside (3), naringenin (4), naringenin-4'-methoxy-7-O-α-L-rhamnoside (5), eriodictyol-3',7-dimethoxy-4'-O-β-D-glucoside (6) and isorhamnetin-3-O-rhamnoglucoside (7), which are reported for the first time ...
Bartowsky Eveline J - - 2011
Malolactic fermentation (MLF) is the bacterially driven decarboxylation of L: -malic acid to L: -lactic acid and carbon dioxide, and brings about deacidification, flavour modification and microbial stability of wine. The main objective of MLF is to decrease wine sourness by a small increase in wine pH via the metabolism ...
Babu R Suresh - - 2011
A novel amperometric sensor for the determination of uric acid was fabricated using room temperature ionic liquid and nickel hexacyanoferrate nanoparticle composite which was immobilized on paraffin wax impregnated graphite electrode. The nickel hexacyanoferrate nanoparticle was characterized by UV-vis, X-ray diffraction and field emission scanning electron microscopy. The electrochemical behavior ...
Fu Jing - - 2011
The specificities of carboxypeptidases from Actinomucor elegans were investigated by determining enzymatic activities at pH 7.0 and pH 4.0 with 16 Z-dipeptides and three Z-tripeptides as substrates. The debittering effect was evaluated and the free amino acid compositions of the soybean protein hydrolysates were analyzed before and after treatment with A. elegans ...
Yu Kyung Ok - - 2011
The high price of petroleum-based diesel fuel has led to the development of alternative fuels, such as ethanol. Saccharomyces cerevisiae was metabolically engineered to utilize glycerol as a substrate for ethanol production. For the synthesis of fatty acid ethyl esters (FAEEs) by engineered S. cerevisiae that utilize glycerol as substrate, ...
Yuan Zhimin - - 2011
CdTe quantum dots (QDs) were prepared in an aqueous solution using various mercaptocarboxylic acids, such as 3-mercaptopropionic acid (MPA) and thioglycolic acid (TGA), as stabilizing agents. The experimental result indicated that these stabilizing agents played an important role for the properties of the QDs. Although both TGA and MPA-capped CdTe ...
Qureshi Mohd Shadbar - - 2011
Lactic acid produced by fermentation process mostly contains a number of aliphatic carboxylic acids as impurities. In this work, carboxylic acid impurities in lactic acid samples from a number of sources were determined at ppm levels. A simple HPLC method was developed that utilized a new generation polar embedded reverse ...
Jaworska G - - 2011
This study provides a qualitative comparison of blackcurrant and blackcurrant-whey beverages over a 12-month storage period. The amount of extract in the beverages was established as 12%, of which 25% was blackcurrant concentrate. Acid whey was used for the production of blackcurrant-whey beverages. In comparison to blackcurrant-whey beverages, blackcurrant beverages ...
Lemaire Arnaud - - 2011
A simple synthesis pathway has been developed for the design of hierarchically structured spongy or spherical voids assembled meso-macroporous aluminosilicates with high tetrahedral aluminium content on the basis of the aqueous polymerisation of new stabilized alkoxy-bridged single molecular precursors. The intimate mixing of an aluminosilicate ester (sec-BuO)(2)-Al-O-Si(OEt)(3) and a silica ...
Teichert Sarah A - - 2011
Stearidonic acid soybean oil (SDASO) is a plant source of n-3 polyunsaturated fatty acids (n-3 PUFAs). Solvent-free enzymatic interesterification was used to produce structured lipids (SLs) in a 1 L stir-batch reactor with a 1:2 substrate mole ratio of SDASO to tripalmitin, at 65<sup>o</sup>C for 18 h. Two SLs were ...
Zhou Zhengxiong - - 2011
The effects of temperature, agitation rate and medium composition, including concentrations of glucose, soybean peptone, and inorganic ions, on pellet formation and pellet diameter of Rhizopus delemar (Rhizopus oryzae) NRRL1526 during pre-culture were studied. Inorganic ions and soybean peptone had negative and positive effects on pellet formation, respectively. The initial ...
Véras Ilvania C - - 2011
This work aims to demonstrate the enzymatic production of fatty acid ethyl ester biodiesel from highly acidic feedstock in a single-step reaction, without co-solvents and avoiding the inhibition of the enzyme by ethanol and glycerol. Additionally, an empirical equation is proposed to predict the kinetics of the production reaction as ...
Forrest Andrea K - - 2011
The MixAlco™ process biologically converts biomass to carboxylate salts that may be chemically converted to a wide variety of chemicals and fuels. The process utilizes lignocellulosic biomass as feedstock (e.g., municipal solid waste, sewage sludge, and agricultural residues), creating an economic basis for sustainable biofuels. This study provides a thermodynamic ...
Kim Hyun Jung - - 2011
Our previous study showed β-glucan with low molecular weight (MW, 1.56 × 10<sup>5</sup> g/mol) bound more bile acid and produced greater amounts of short-chain fatty acids (SCFA) than did -glucan with high MW (Mn = 6.87 × 10<sup>5</sup> g/mol). In the current study, β-glucan extracted from oat flour was fractionated ...
Shi Zheng - - 2011
A visible-light activatable photoacid has been studied, which upon irradiation, changes from a weak acid, with a pKa of 7.8, to a strong acid, which achieves nearly complete proton dissociation. This process is reversible and the lifetime of the proton-dissociation state is ~70s. The long lifetime of the proton-dissociation state ...
Morita Tomotake - - 2011
Cryptococcus humicola JCM 1461 efficiently produced cellobiose lipids (CLs), bolaform biosurfactants. The main product was identified as 16-O-(2″,3″,4″,6'-tetra-O-acetyl-β-cellobiosyl)-2-hydroxyhexadecanoic acid. The production yield of CLs reached 13.1 g/L under the intermittent feeding of glucose. The critical micelle concentrations (CMC) of the main product at pH 4.0 and 7.0 were 3.3×10(-5) M ...
Gao Chao - - 2011
Lactic acid, the most important hydroxycarboxylic acid, is now commercially produced by the fermentation of sugars present in biomass. In addition to its use in the synthesis of biodegradable polymers, lactic acid can be regarded as a feedstock for the green chemistry of the future. Different potentially useful chemicals such ...
Liao Li - - 2011
A new agarase, AgaA(CN41), cloned from Vibrio sp. strain CN41, consists of 990 amino acids, with only 49% amino acid sequence identity with known β-agarases. AgaA(CN41) belongs to the GH50 (glycoside hydrolase 50) family but yields neoagarotetraose as the end product. AgaA(CN41) was expressed and characterized.
Hibi Makoto - - 2011
We determined the enzymatic characteristics of an industrially important biocatalyst, α-ketoglutarate-dependent l-isoleucine dioxygenase (IDO), which was found to be the enzyme responsible for the generation of (2S,3R,4S)-4-hydroxyisoleucine in Bacillus thuringiensis 2e2. Depending on the amino acid used as the substrate, IDO catalyzed three different types of oxidation reactions: hydroxylation, dehydrogenation, ...
Poureslami Reza - - 2011
BACKGROUND: The health benefits of n-3 fatty acids have led to much research on manipulating the fatty acid composition of animal-derived foods. In this study, two experiments were conducted to investigate the interaction of dietary fatty acids on egg yolk fatty acid concentrations. In experiment I, 32 dietary treatments with ...
Berenjian Aydin - - 2011
The aim of this study was to assess the effect of nutrients on the production of menaquinone-7 and determine the optimum conditions to achieve a high concentration of this product. Bacillus subtilis natto was fermented at 40°C for a period of six days. Design of experiments was used for screening ...
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