Showing papers on "Citric acid published in 1977"

Influence of manganese on enzyme synthesis and citric acid accumulation inAspergillus niger

Abstract: A comparison of citric acid fermentations in manganese-deficient and manganese-containing media showed that manganese strongly influences idiophase metabolism In the presence of manganese, cell growth increases, sugar consumption is diminished and acidogenesis decreases drastically An investigation of the key enzymes of glycolysis, the pentosephosphate pathway, TCA-cycle, nitrogen metabolism, and gluconeogenesis indicated that manganese deficiency was accompanied by a repression of anabolic and TCA-cycle-enzymes with the exception of citrate synthase The activity of this enzyme and the enzymes of glycolysis paralleled the sugar consumption rate In the presence of manganese, no repression of enzyme synthesis was observed Activities of 2-oxoglutarate dehydrogenase and isocitrate lyase could not be detected in either case The results support the hypothesis that manganese deficiency mainly affects the operation of biosynthetic reactions inAspergillus niger, thus leading to an overflow of citric acid as an end product of glycolysis

Organic acid and potassium accumulation in guard cells during stomatal opening.

Abstract: Leaflets of Vicia faba L. with either open or closed stomata were quick-frozen and freeze-dried. Individual guard cell pairs and pure samples of palisade parenchyma, spongy parenchyma, and epidermis lacking guard cells were dissected from the leaflets, weighed, and assayed for organic acids or K+.K+ was measured by a new enzymatic method. In guard cells of open stomata, as compared to closed stomata, K+ was 2- to 4-fold higher, malic acid 6-fold higher, and citric acid 3-fold higher. Both aspartic and glutamic acids were also higher, but the amounts present were low compared to malic and citric acids. Isocitric acid was significantly higher in one experiment, but not in another. Glyceric acid was not increased. Succinic acid was too low to detect by the method used; but in guard cells of open stomata the concentration must have been less than 2% of that of malic acid. Malic acid was higher in the palisade parenchyma from the leaflet with open stomata. The ion balance shows that malic and citric acids provide much of the counter ion for the K+ taken up during stomatal opening

Antimicrobial compositions and methods for utilizing the same employing mixtures of amines

Abstract: There are provided antimicrobial compositions of the low toxicity having enhanced activity against gram positive and gram negative bacteria as well as fungi or protozoa and consists essentially of: (a) an alkyl-N-betaine in amounts up to 40 parts, by weight, (b) an alkyl-N,N-dimethylamine oxide, an alkyl-N,N-dihydroxy-ethylamine oxide, or an acylamido t-amine oxide in amounts up to 40 parts, by weight, and (c) a protonating agent, such as hydrochloric acid, acetic acid or citric acid in an amount sufficient to adjust the pH of the overall composition to from about 4.0 to about 5.5. The composition exhibits skin degerming, cleansing, and deodorizing properties and, particularly, its use exhibits long term inhibition of body odor.

Citric acid fermentation of brewery waste

Abstract: Spent grain liquor, a brewery waste, was used as a fermentation medium for the production of citric acid by Aspergillus foetidus (formerly called A. niger NRRL 337.) The yields of citric acid varied from 3.5–12.3g/liter of the waste fermented, depending on the samples. On the basis of the reducing sugar consumed, the yields ranged from 42–58%. The added nitrogen compounds increased mycelial growth and the consumption of sugar, but markedly reduced the amount of citric acid formed. The addition of phosphate (KH2PO4) appeared to have little effect on mycelial growth and citric acid production. Methanol in concentrations of 2–4% markedly increased the formation of citric acid from the waste. There was a reduction in mycelial growth associated with the use of methanol.

Citric acid consumption and the human dentition

Abstract: The action of citric acid and its effect on dental tissues is discussed, and two cases are presented in which the appearance of affected tooth surfaces was improved with the use of a composite resin. Besides caries, various destructive processes of the dental hard tissues are rather common in the form of erosions and abrasions. Two cases and treatment of a specific type of pernicious process ascribed to the abusive use of citric acid are described. A discussion of the action of citric acid and its effect on dental tissues is presented. The question is raised as to the possible contribution of citric acid to the origin of other erosive processes.

Enzymatic formation of glutathione-citryl thioester by a mitochondrial system and its inhibition by (-)erythrofluorocitrate.

Abstract: A soluble extract of the mitochondrial compartment composed of the inner membrane and matrix catalyzes the enzymatic synthesis and hydrolysis of the 1:1 adduct of citric acid and glutathione. The adduct was identified as the thioester by isolation with single and double isotope labeling ([14C]citric acid and [35S]glutathione) and by conversion to the monohydroxamate of citric acid and comparison with the synthetic product by thin layer chromatography and high voltage electrophoresis. The enzymatic formation of the thioester (pH optimum 7.39 at 30°) requires oxidized glutathione and citrate; both substrates exhibit a Michaelis-Menten kinetics. During the enzymatic reaction equimolar quantities of thioester and glutathione sulfinic acid are formed. After gel filtration or salt fractionation the enzyme system requires Mn2+ (or Mg2+, which is less effective) for maximal activity. When extracts of mitoplast are tested, the time course of reaction is biphasic due to the rapid synthesis of the product by the thioester-forming system (molecular weight 171,000) followed by its decay by the hydrolase (molecular weight 71,000). The two systems were separated by molecular filtration on Sephadex G-200 and by precipitation with (NH4)2SO4. The thioester-forming system is inhibited by preincubation with 0.5 mM mersalyl. Other inhibitors are 1,2,3-propane tricarboxylic acid, 10 mM Ca2+, 200 mM K+, and the free radical trapping agent, phenazine methosulfate. The citrate-glutathione thioester formation is irreversibly and specifically inhibited by (-)erythrofluorocitrate (50% inhibition at 25 pmol of added fluorocitrate per mg of protein), which forms a trichloroacetic acid-stable adduct with the enzyme protein (at 50% inhibition, 0.8 pmol is bound to 1 mg of protein). Synthesis of malyl-glutathione thioester by inner membrane vesicles is selectively inhibited by (-)erythrofluoromalate.

Corrosion inhibiting composition and process of using same

Abstract: This invention is directed to a corrosion inhibiting composition and to a process for inhibiting corrosion and the deposition of mineral scale on metal in aqueous systems which comprises adding to the water effective amounts of citric acid and/or the alkali metal salts thereof or combinations of a metal molybdate with citric acid and/or an alkali metal salt thereof and at least one amino methylene phosphonic acid or a derivative thereof.

Oral and topical compsns. for psoriasis treatment - contg. fumaric acid (derivs.) and diluent contg. org. acid salts.

Abstract: A palatable, oral compsn for treatment of psoriasis, which is easy to measure out, consists of >=1 fumaric acid cpd. (I) diluted with the acid alkali salts of tartaric citric and ascorbic acid, and with MgSO4 and sugar, and is administered dissolved in water. (I) is fumaric acid itself; its neutral or acid salts:di- or mono-esters or their salts including Mn salts. Also new are topical (I)-based compsns. applied together with the acid salts of tartaric and citric acids and opt. with Vitamin A acid. The compsns. quickly normalise the metabolic status in cases of psoriasis and also improve circulatory disorders and senile diabetes, and normalise cholesterol levels. The solns. have an acceptable baste, are readily accepted by children and alleviate gastric and intestinal disorders from which many psoriasis patients suffer. A compsns. for adding to bathing water comprises (wt. pts.) fumaric acid 100; dimethyl fumarate 100; tartaric acid 100; K or NaHCO3 150; citric acid 50. 2-5 Teaspoons are added to the bath.

Regulation of the central metabolism in relation to citric acid production in Saccharomycopsis lipolytica

Abstract: The mechanism of the massive extracellular production of citric and isocitric acids by Saccharomycopsis lipolytica grown on n-paraffins has been studied. When growth stops, because of nitrogen limitation, the intracellular concentration of ATP sharply rises whereas that of AMP and ADP decreases to a low level. At the same time production of acids begins. The activity of the NAD-dependent isocitrate dehydrogenase which requires AMP for activity becomes very low and prevents the oxidative function of the citric acid cycle whereas isocitrate lyase is not inhibited. As citrate synthase inhibition by ATP appears to be insufficient to stop n-paraffin degradation, citric and isocitric acids accumulation can take place. Massive excretion of these acids, however, probably still involves other physiological changes brought about by nitrogen limitation, possibly some permeabilization of the cell to these acids.

Subcellular structures in fermenting cocoa beans. Effect of aeration and temperature during seed and fragment incubation

Abstract: Chemical reactions in cocoa seeds during fermentation and roasting may depend on post-mortem structural changes in the mesophyll cells. Aeration, temperature and acetic acid concentration vary considerably during commercial fermentation. Light and electron microscopic studies of seeds after artificial fermentations give evidence that the kind and the degree of subcellular structural changes depend on these variations. At 50°C in the presence of acetic acid (35 mM/litre, pH 4.0) water-containing compartments are destroyed shortly before the lipid vacuoles fuse. The hydrophilic particles of the plasm become dispersed within the lipid phase. These changes occur within 6–20 h independent of the presence of air. At 40°C in the absence of acetic acid (citric acid, pH 5.5) the seeds germinate and protein vacuoles in many cells of the mesophyll inflate considerably within 6 h, which is before post-mortem structural changes, different from those following treatment in acetic acid at 50°C, become obvious. Incubation of cotyledon fragments instead of whole seeds submerged in buffer induced these structural changes as well and were even more pronounced. The significance of temperature differences in the range of 40–50°C and induction of germination during fermentation is discussed.

Production of citric acid from n-paraffins bySaccharomycopsis lipolytica: Kinetics and balance of the fermentation

Abstract: The excretion of citric and isocitric acids was studied in a stirred fermentor with control of various fermentation parameters. Growth being nitrogen-limited, excretion was found to start at the end of the growth phase, constant production rates being then obtained for the two acids for about 90 h. A linear relationship between these production rates and cell density is observed, thus allowing a definition of specific production rates. Variation of these rates with temperature, aeration, pH and medium iron content were studied. The main effects observed are those of pH, which shows a clear optimum at pH 5, and of iron content, the lower values of which promote citric acid excretion. During the excretion phase rate measurements for all reactants (n-paraffins-oxygen) and products (carbon dioxide-citric and isocitric acids) show that good carbon and oxygen balance are obtained. Comparison with a similar fermentation using glucose is also presented and discussed.

Oral scour formulations with citrate

Abstract: A veterinary composition comprising 40 to 80% of an actively absorbed monosaccharide, 7.5 to 30% of an actively absorbed naturally occurring amino acid, and 0.5 to 10% of an agent which is citric acid or a salt thereof; except that when the agent is a salt of citric acid, then the amino acid represents no more than 13% of the composition; are useful in the treatment of diarrhoea in animals such as calves.

Metal oxide remover containing a strong mineral acid, citric acid and a basic ammonia derivative

Abstract: Composition and method for removing metal oxides from ferrous metals. The composition contains an ammonia derivative such as an amine, a strong mineral acid and citric acid in an aqueous solution having an acidic pH of about 0.5-3.0. Metal oxides are removed by applying the solution at elevated temperature.

Lack of Effect of Ascorbic and Citric Acids on Calcium Metabolism of Chickens

Abstract: Five experiments were carried out in which various levels of calcium and ascorbic acid or citric acid were fed to adult male chickens, young chickens, or young coturnix. Observations were made on body weight, feed efficiency, plasma calcium and tibia mineral content. One percent dietary ascorbic acid had no adverse effect on body weight, tibia ash or tibia calcium content of adult male chickens over a 224-day period, even at calcium levels as low as 0.026% of the diet. In growing chicks, body weight and plasma calcium and tibia mineral content varied with the calcium level of the diet, but were not influenced by ascorbic acid even at 0.65% of the diet. Citric acid at the same molar level was also ineffective in altering calcium metabolism in growing chickens. Growing coturnix showed differences in growth and tibia ash content with 0.4% and 0.85% calcium, but there were no pronounced effects caused by dietary ascorbic acid. There is no evidence in this work that these relatively high levels of ascorbic acid or citric acid have any adverse effect on calcium metabolism because of their chelating properties.

Use of citric acid to make catalyst from catalyst fines

Abstract: The addition of citric acid to large amounts of catalyst fines allows their incorporation into catalyst formulations without the loss of important physical properties.

Preparation of lllysine

Abstract: PURPOSE:To obtain L-lysine in high yield, by cultivating a variant, belonging to the genus Brevibacterium or Corynebacterium, having lower activities of citric acid synthesizing enzyme than a parent strain and no demanding properties for L- glutamic acid. CONSTITUTION:A variant having L-lysine producing cmpetence, derived from Brevibacterium devaricatum ATCC14020 as a parent strain, etc., belonging to the genus of Brevibacterium or Corynebacterium, having lower activities of citric acid synthesizing enzyme than the parent strain, possessing no L-glutamic acid demanding properties, is cultivated. The cultivation is carried out using an ordinary nutrient medium conventionally. It is done under aerobic conditions at 24-37 deg.C in pH5-9 for 2-7 days, and L-lysine is collected from the culture solution by a method, e.g., ordinary ion exchange resin method, etc.

CO{HD 2 {B measurement and reagents therefor

Abstract: Reagent compositions for use in CO2 analysis which comprise certain acids and/or buffered acids together with selected additives. The acids and buffered acids have pH less than 4 and a vapor pressure not in excess of 10mm mercury. Examples of these acids include lactic acid, citric acid, phosphoric acid, sulfuric acid, perchloric acid, malic acid, malonic acid, oxalic acid, naphthalenesulfonic acid, picric acid, sulfamic acid, and nitric acid. The additives, which can be used separately or with one another, are ethers of fatty alcohols and polyoxyethylene (having the structure R-O-(C2H4-O)nH), glycerin, polyvinyl alcohol, and pH sensitive indicator dyes, including methyl red, p-nitrophenol, neutral red, phenolphthalein, and o-cresolphthalein. An improved method for analysis of CO2 in body fluids comprises the steps of adding these reagents to body fluid samples to release CO2 therefrom into a gas space, displacing the released CO2 to a detector, and measuring the amount of released CO2 in the detector. Generally, acid reagents including at least one of the ethers of fatty alcohols and polyoxyethylene are preferable for releasing CO2 from a body fluid sample.

Effect of Blue Light on Metabolism in Penicillium isariiforme

Abstract: Summary: In blue light Penicillium isariiforme assimilates less CO2 and excretes less citric acid into the medium than when grown in continuous darkness. This is due to a decreased supply of pyruvate which is carboxylated to form citric acid via oxaloacetate. Pyruvate carboxylase rather than phosphoenolpyruvate carboxylase or phosphoenolpyruvate carboxykinase is mainly responsible for CO2 assimilation in this fungus. Of the glycolytic intermediates assayed, steady-state concentrations of pyruvate were low and concentrations of glucose 6-phosphate, glucose 1-phosphate and fructose 6-phosphate were high in mycelium grown in the light compared with those in mycelium grown in the dark. Results of experiments with specifically-labelled glucose suggest that light stimulates the pentose phosphate pathway and inhibits the supply of pyruvate for citric acid synthesis via the Embden–Meyerhof–Parnas pathway.

Influence of Citric Acid on Reactions in the System 3CaO·Al2O3‐CaSO4·2H2O‐CaO‐H2O

Abstract: The influence of citric acid on paste hydration of 3CaO· Al2O3 in the presence of CaSO4·2H2O and Ca(OH)2 was studied using X-ray diffraction, scanning electron microscopy, and conduction calorimetry. The time at which the citric acid is added (either prior to or with the mixing water) determines how it affects the reactivity of the aluminate. Immediately after the paste is gaged citric acid promotes a more rapid reaction, but later reactions are retarded. Hexagonal calcium aluminate hydrates, ettringite, and monosulfate were all detected as early hydration products. The influence of citric acid on the hydration of 3CaO·Al2O3 slabs immersed in saturated CaSO4·2H2O solutions was also studied and a reaction scheme proposed.

Anaerobic incorporation of radioactivity from 2,3-14C-succinic acid into citric acid cycle intermediates and related compounds in the sea musselMytilus edulis L.

Abstract: Sea mussels were exposed to nitrogen for various periods (0, 1, 3 and 6 days) and subsequently injected with 2,3-14C-succinic acid. After 2.5 h anaerobic incubation concentrations of succinate, some amino acids and volatile fatty acids were determined as well as the distribution of radioactivity.

Determination of citric acid and its decomposed products in edible oils by gas liquid chromatography

Abstract: A quantitative gas liquid chromatographic (GLC) method for four organic acids-citric, aconitic, itaconic, and citraconic acids-in refined oils and fats was developed. After the organic acids are extracted with water from soybean oils, the extract is esterified with n-butanol and an aliquot of the ester is subjected to GLC on a temperature-programmed 10% DEGS column equipped with a flame ionization detector. At 20 and 30 ppm levels, recoveries of the acids from the oil varied from 95 to 100% except for itaconic acid. Citric acid content in commercial edible oils in Japan was from trace to 16 ppm. However, aconitic, itaconic, and citraconic acids were not detected.

Effects of Cultivars and Fertilizers on Nonvolatile Organic Acids in Potato Tubers

Abstract: The nonvolatile acids were extracted from potatoes and isolated by ion exchange chromatography. They were then analyzed by paper chromatography and gas-liquid chromatography (GLC) in conjunction with mass spectrometry. The GLC procedure involved a preparation of trimethylsilyl derivatives of the nonvolatile acids followed by their separation on 3% SE-52 or OV-3 liquid phase using glutaric acid as an internal standard. Citric, malic, 2-pyrrolidone-5-carboxylic (PCA), and phosphoric acids were found to be the major acids in potatoes. Citric and malic acids accounted for 93% of total acidity in Netted Gems. Cultivar variations in the relative abundance of the major acids were observed. Excessive amounts of nitrogen fertilization were found to cause a substantial decrease in cirtric and malic acids and increase in PCA and phosphoric acid. However, the total acidity declined as the fertilizer application was increased. Since the rate of formation of PCA, a bitter principle in cooked potatoes, depends upon glutamine content, the excessive use of nitrogen fertilizer should be avoided if the accumulation of glutamine is to be controlled. Also, a high concentration of citric acid would be required to prevent discoloration of cooked potatoes.

Acidic zinc phosphate solution and method

Abstract: An aqueous acidic oxidant-free zinc phosphate solution contains tartaric acid, citric acid and/or a salt of either. At a pH of about 3.5 to 4.7, the solution produces a microcrystalline coating of zinc phosphate on iron or steel. The solution preferably contains nickel ion also.

Seminal fructose, citric acid and phosphatase levels and their relation to the sperm count in man.

Abstract: Seminal fructose, citric acid and phosphatase levels were estimated in 60 normal adults and compared with 60 oligospermic and 24 azoospermic Indian subjects. In normal group, the seminal plasma fructose level and acid phosphatase activity showed a fall as the sperm count increased. As compared to normals, significantly higher mean values for fructose and acid phosphatase activity were observed in oligospermic and azoospermic groups. Seminal alkaline phosphatase activity did not show any relationship with sperm count. Similarity in changes observed in seminal fructose and acid phosphatase levels with respect to seminal citric acid content and sperm concentration suggests that both these parameters are probably regulated by similar physiological mechanism.