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PubMed1992

Utilization of tartaric acid and related compounds by yeasts: taxonomic implications.

A survey of yeasts capable of growing on L(+)-tartaric acid as the sole source of carbon and energy showed that this organic acid is assimilated by a significant number of species of basidiomycetous affinity and is seldom utilized by ascomycetous yeasts. This conclusion was further supported by the fact that among approximately 100 isolates from various natural substrates, using selective media with L(+)-tartaric acid, only one strain of ascomycetous affinity was obtained. In a more comprehensive survey 442 yeast strains belonging to 138 species, mostly of basidiomycetous affinity, were also screened for the assimilation of different aldaric acids: D(-)-tartaric acid, meso-tartaric acid, L(-)-malic acid, D(+)-glucaric acid (saccharic acid), and galactaric acid (mucic acid). L(+)-Tartrate was the most frequently utilized tartaric acid isomer (55% of the total number of strains of basidiomycetous affinity belonging to either the Tremellales/Filobasidiales or the Ustilaginales) when compared with the D(-) and meso forms, which were assimilated by 12 and 18% of the total number of strains, respectively (mainly of tremellaceous species). Saccharic acid was utilized by about 75% of the total number of species of Tremellales affinity and by less than 20% of the ustilaginaceous species. Assimilation of mucic acid occurred in more than 50% of the tremellaceous species and only in 5% of the species related to the Ustilaginales. These tests, not used in standard yeast identification sets, appear to contribute to distinguishing taxa at or above the species level.

Basidiomycota↗
PubMed1996

Acceptance of minerals and other compounds by calcium-deprived rats: 24-h tests.

We measured 24-h spontaneous intake of four to eight concentrations of 31 different solutions by groups of rats fed control or low-calcium diets. Relative to controls, those fed low-calcium diet had increased acceptance of one or more concentrations of sodium chloride, sodium acetate, and sodium bicarbonate, but not sodium gluconate. Differences in palatability between these sodium salts were unimportant because the rats fed low-calcium diet consumed more sodium chloride even if this was made less acceptable by adulteration with citric acid. The possibility that calcium-deprived rats have an enhanced general cation or mineral appetite was supported by findings of increased acceptance of one or more concentrations of nine of ten chloride minerals tested (aluminum chloride, ammonium chloride, ferric chloride, ferrous chloride, magnesium chloride, sodium chloride, potassium chloride, strontium chloride, zinc chloride). However, there were no differences in acceptance of any concentration of cesium chloride, magnesium sulfate, or lead acetate. Moreover, calcium-deprived rats drank more hydrochloric acid and malic acid than did controls. Thus the effect of calcium deficiency on intake was not confined to minerals. Acidity or bitterness did not appear important because there was no difference between the groups in intake of sulfuric acid, citric acid, or quinine hydrochloride. Consistent with the exacerbating effects of phosphates on calcium deprivation, deprived rats had decreased intakes of phosphates (sodium phosphate, potassium phosphate). However, they also had decreased intakes of sucrose and saccharin. It is clear that calcium deprivation does not induce a general increase in acceptance of all taste solutions, but there appears to be no simple explanation for what these animals consume.

Acids↗
PubMed1975

Histochemical demonstration of mitochondrial dehydrogenases in developing normal and nervous mutant mouse Purkinje cells.

The mouse mutation nervous (nr), expressed as a recessive, causes a morphologic change in cerebellar Purkinje cell perikaryonal mitochondria during the 2nd postnatal week which is followed by the selective degeneration of most Purkinje cells. In the present study, mitochondrial dehydrogenase activities (succinic acid dehydrogenase, lactic acid dehydrogenase, malic acid dehydrogenase, reduced diphosphopyridine nucleotide diaphorase and succinic semialdehyde dehyrogenase) are found by light microscopy to be similar in the perikarya of normal and nervous Purkinje cells until after mitochondrial rounding has begun to occur, but then staining increases markedly in nervous. Although only a small fraction of mitochondrial functions were examined, those enzymes assayed were present and competent. In a sense, the only mitochondrial abnormalities demonstrated thus far in nervous Purkinje cells are their unusual shape and probable loss of motility.

Aging↗
PubMed2005

Effect of postinduction nutrient feed composition and use of lactose as inducer during production of thermostable xylanase in Escherichia coli glucose-limited fed-batch cultivations.

Escherichia coli is a microorganism routinely used in the production of heterologous proteins. The overexpression of a xylanase (Xyn 10 A Delta NC), which originated from the thermophile Rhodothermus marinus cloned under the control of the strong T7/lac promoter in a defined medium (mAT) using a substrate-limited feed strategy, was however shown to impose a significant metabolic burden on host cells. This resulted in a decreased cell growth rate and ultimately also a decreased target protein production. The investigation hence centers on the effect of some selected nutrient feed additives (amino acid [Cys] or TCA-intermediates [citrate, succinate, malate]) used to relieve the metabolic burden imposed during the feeding and postinduction phases of these glucose-limited fed-batch cultivations. The use of either succinic acid or malic acid as feed-additives resulted in an increase in production of approximately 40% of the heterologous thermostable xylanase. Furthermore, use of lactose as an alternative inducer of the T7/lac promoter was also proven to be a suitable strategy that significantly prolonged the heterologous protein production phase as compared with induction using isopropyl beta-D-thiogalactopyranoside (IPTG).

Bioreactors↗
PubMed2003

Simultaneous monitoring of organic acids and sugars in fresh and processed apple juice by Fourier transform infrared-attenuated total reflection spectroscopy.

A combination of Fourier transform infrared spectroscopy (FT-IR) and chemometrics was used as a screening tool for the determination of sugars and organic acids such as sucrose, glucose, fructose, sorbitol, citric acid, and malic acid in processed commercial and extracted fresh apple juices. Prepared samples of synthetic apple juice in different constituent concentration ranges were scanned by attenuated total reflectance (ATR) accessory and the spectral region in the range between 950 and 1500 cm(-1) was selected for calibration model development using partial least squares (PLS) regression and principal component regression (PCR). The calibration models were successfully validated by high-performance liquid chromatography (HPLC) measurements against several commercial juice varieties as well as juice extracted from different apple varieties to provide an overall R2 correlation of 0.998. The present study demonstrates that Fourier transform infrared spectroscopy could be used for rapid and nondestructive determination of multiple constituents in commercial and fresh apple juices. Results indicate this approach to be a rapid and cost-effective tool for routine monitoring of multiple constituents in a fruit juice production facility.

Beverages↗
PubMed2005

Inhibition of specific degradation of 57-kDa protein in royal jelly during storage by citrate buffer.

We have previously shown that ethylenediaminetetraacetic acid (EDTA) suppresses the storage-dependent degradation of 57-kDa protein, which is a possible marker for freshness and quality of royal jelly (RJ) through the inhibition of a proteinase in RJ. We suggested that EDTA could be useful as a preservative agent to maintain the quality of RJ. Here, we report the effects of other metal chelators, di- or tricarboxylic acids such as citric acid and malic acid, on proteinase activity in RJ and the specific degradation of 57-kDa protein during storage. Various carboxylic acids inhibited the proteinase activity in RJ, but did not suppress storage-dependent degradation of 57-kDa protein. However, when RJ was stored with various carboxylate buffers (pH 4.0) at 40 degrees C, the degradation of 57-kDa protein during storage was suppressed through the inhibition of proteinase in RJ. Among the buffers, citrate buffer (pH 4.0) effectively inhibited the decrease of 57-kDa protein concentration in RJ during storage. These results suggest that citrate buffer (pH 4.0) could be available as a new preservative agent to maintain the quality of RJ.

Animals↗
PubMed2001

[Chelate-induced phytoextraction of copper contaminated upland red soil].

A copper spiked red soil was used in pot experiment to study the effects of EDTA and low molecule weight organic acids on Cu speciation in soil, and Cu uptake by Brassica juncea. The results showed that the mobility of Cu in soil was improved obviously when EDTA was added at the vigorous growth stage. Both water-extractable and exchangeable Cu concentration increased significantly following EDTA addition. Citric acid and malic acid only had an effect on water-extractable Cu, and no effect on Cu uptake by the plant. EDTA significantly increased the concentration of Cu in plant leaves and roots, and the Cu uptake by Brassica juncea. All of these indicated the chelate-induced phytoextraction.

Absorption↗
PubMed2005

[Organic acid secretion and its detoxification mechanism in plant roots under aluminum stress].

Phytotoxicity of Al is becoming one of the most serious problems in limiting plant growth on acid soils. Under Al stress, a number of plant species, cultivars or genotypes exhibit inheritable tolerance by organic acid secretion which is specific to Al stress and localized to the root apex. Citric acid, oxalic acid and malic acid are thought to be the most effective organic acids in detoxifying Al. Organic acid detoxifies Al both extracellular and intracellular. Two exudation patterns and their related speculation are introduced in this review. The possible factors responsible for the organic acid secretion are discussed, which are also the research focuses in this field. At last, we put forward our perspective in the field.

Aluminum↗
PubMed2005

Degradation of 2,6-di-tert-butylphenol by an isolated high-efficiency bacterium strain.

An aerobic bacterium strain, F-3-4, capable of effectively degrading 2, 6-ditert-butylphenol (2, 6-DTBP), was isolated and screened out from an acrylic fiber wastewater and the biofilm in the wastewater treatment facilities. This strain was identified as Alcaligenes sp. through morphological, physiological and biochemical examinations. After cultivation, the strain was enhanced by 26.3% in its degradation capacity for 2,6-DTBP. Results indicated that the strain was able to utilize 2,6-DTBP, lysine, lactamine, citrate, n-utenedioic acid and malic acid as the sole carbon and energy source, alkalinize acetamide, asparagine, L-histidine, acetate, citrate and propionate, but failed to utilize glucose, D-fructose, D-seminose, D-xylose, serine and phenylalanine as the sole carbon and energy source. The optimal growth conditions were determined to be: temperature 37 degrees C, pH 7.0, inoculum size 0.1% and shaker rotary speed 250 r/min. Under the optimal conditions, the degradation kinetics of 2,6-DTBP with an initial concentration of 100 mg/L was studied. Results indicated that 62.4% of 2,6-DTBP was removed after 11 d. The degradation kinetics could be expressed by Eckenfelder equation with a half life of 9.38 d. In addition, the initial concentration of 2,6-DTBP played an important role on the degradation ability of the strain. The maximum initial concentration of 2,6-DTBP was determined to be 200 mg/L. Above this level, the strain was overloaded and exhibited significant inhibition.

Alcaligenes↗
PubMed1995

[Effect of selected additives on the quality of the Wegirka Zwykła brand of frozen plums].

The aim of the work was to determine the effect of sugar, pectin formulation, and L-ascorbic acid on selected physico-chemical properties and organoleptic quality of frozen Wegierka Zwykła plums. Sugar at a dose of 10 g per 100 g of fruit in a loose form or as 60% syrup was used separately or with an addition of pectins or 0.5% L-ascorbic acid. A 1.5% solution of pectins at a dose of 10 g per 100 g of fruit was used separately or with an addition of 0.5% l-ascorbic acid. Plums were cut into halves, stoned, treated with an additives, placed in plastic containers, and frozen at -30 degrees C. The temperature of -20 degrees C at which frozen products were stored, was obtained after 90 min. The evaluation was carried out at the stage of row material and of frozen fruit directly after freezing and after 12-month storage. In the case of vitamin C and anthocyanins analyses were conducted at 3-month intervals. Fresh fruit contained 18.4% of dry weight, 11.3% of total sugars, 0.81% of acids as malic acid, 12.7 mg/100 g of vitamin C, and 17.9 mg/100 g of anthocyanins. The addition of additives contributed to variability of frozen fruit with respect to the level of dry matter and sugars, and brought about a slight dilution of acids, vitamin C, and anthocyanins. Freezing did not significantly change the content of vitamin C and anthocyanins. On the other hand, one-year storage of the product frozen without the additives brought about a decrease in the content of vitamin C to 3.6 mg/100 g and of anthocyanins to 1.9 mg per 100 g of fruit. In the samples with the additives the respective values were 4.6-13.5 mg and 3.2-6.7 mg. After 12-month storage the organoleptic quality of frozen products without the antioxidants was 3.82 and of those with the antioxidants added 4.04-4.76 in a 5-score scale. From the analysed variants of additives used in freezing plums for dessert sugar syrup with an addition of L-ascorbic acid may be recommended on account of a good preservation of components, high organoleptic value, and also simple way of application. A solution of pectins with L-ascorbic acid can be used in preparing frozen fruit for people not tolerating sugar in their diet.

Anthocyanins↗
PubMed1977

Inhibitory effect of fumaric acid and dicarboxylic acids on gastric ulceration in rats.

Production of gastric ulcerations in rats by pyloric ligation was found to be inhibited by either intraperitoneal or oral administration of fumaric acid in a dose of 50 mg per kg. The antiulcer action was also exhibited by the four-carbon dicarboxylic acids, maleic acid, oxalacetic acid, succinic acid and malic acid. The studies on fumaric acid indicated that the acid's antiulcer action was based on its ability to inhibit the gastric juice secretion and to dilate the stomach muscle.

Animals↗
PubMed1984

Characterization of the vacuolar ATPase activity of the crassulacean-acid-metabolism plant Kalanchoë daigremontiana. Receptor modulating.

Plants performing crassulacean acid metabolism show a large nocturnal accumulation of malic acid in the vacuole of the photosynthetic cells. It has been postulated that an H+-translocating ATPase energizes the transport of malic acid across the tonoplast into the vacuole. In the present work we have characterized the ATPase activity associated with vacuoles of the crassulacean-acid-metabolism plant Kalanchoë daigremontiana and compare it with other phosphohydrolases. Vacuoles were isolated by polybase-induced lysis of mesophyll-cell protoplasts. The vacuoles had a high activity of unspecific acid phosphatase (pH optimum 5.3). The acid phosphatase was strongly inhibited by ammonium molybdate (with 50% inhibition at about 0.5 mmol m-3), but was not completely inhibited even at much higher ammonium-molybdate concentrations. In contrast, the vacuolar ATPase activity, assayed in the presence of 100 mmol m-3 ammonium molybdate, had a pH optimum of 8.0. ATP was the preferred substrate, but GTP, ITP and ADP were hydrolyzed at appreciable rates. The mean ATPase activity at pH 8.0 was 14.5 nmol h-1 (10(3) vacuoles)-1, an average 13% of which was attributable to residual acid-phosphatase activity. Inorganic-pyrophosphatase activity could not be demonstrated unambiguously. The vacuolar ATPase activity was Mg2+-dependent, had an apparent Km for MgATP2- of 0.31 mol m-3, and was 32% stimulated by 50 mol m-3 KCl. Of the inhibitors tested, oligomycin slightly inhibited the vacuolar ATPase activity and diethylstilbestrol and NO-3 were both markedly inhibitory. Dicyclohexylcarbodiimide and tributyltin were also strongly inhibitory. Tributyltin caused a 50% inhibition at about 0.3 mmol m-3. This is taken as evidence that the vacuolar ATPase might function as an H+-translocating ATPase. It is shown that the measured activity of the vacuolar ATPase would be of the right order to account for the observed rates of nocturnal malic-acid accumulation in K. daigremontiana.

Acid Phosphatase↗
PubMed1980

Changes in the hepatic levels of messenger ribonucleic acid for malic enzyme during induction by thyroid hormone or diet.

Levels of hepatic messenger ribonucleic acid (mRNA) for malic enzyme [L-malate:NADP oxidoreductase (decarboxylating), EC 1.1.1.40] were quantitated in different dietary and hormonal states of the rat. Polysomal or total cellular poly(A)-containing RNA was translated in the rabbit reticulocyte lysate system, which had been treated to reduce endogenous mRNA activity. The relative level of incorporation of radiolabeled amino acid into malic enzyme was determined by immunoprecipitation with antibody to malic enzyme and formaldehyde-fixed Staphylococcus aureus (Cowens I strain) as an immunoadsorbent. The immunoprecipitated product comigrated with purified malic enzyme on sodium dodecyl sulfate--polyacrylamide gel electrophoresis. No malic enzyme was detected when nonspecific antisera or an excess of unlabeled malic enzyme was added during immunoprecipitation. The level of malic enzyme mRNA was found to markedly increase relative to euthyroid, chow-fed rats when the animal was either fed a high carbohydrate, fat-free diet or made hyperthyroid. Animals receiving both treatments had a further increase in mRNA activity to a level which was approximately 0.2% of the total incorporation of [3H]leucine. Levels of malic enzyme activity and the relative rate of synthesis were found to increase roughly in proportion to mRNA levels in these three states. Thus, the induction of malic enzyme by thyroid hormone or high carbohydrate, fat-free diet is due largely to an increase in the mRNA coding for this enzyme.

Animals↗
PubMed1989

Soluble Sugars as the Carbohydrate Reserve for CAM in Pineapple Leaves : Implications for the Role of Pyrophosphate:6-Phosphofructokinase in Glycolysis.

Neutral ethanol-soluble sugar pools serve as carbohydrate reserves for Crassulacean acid metabolism (CAM) in pineapple (Ananas comosus (L.) Merr.) leaves. Levels of neutral soluble sugars and glucans fluctuated reciprocally with concentrations of malic acid. Hexose loss from neutral soluble-sugar pools was sufficient to account for malic acid accumulation with about 95% of the required hexose accounted for by turnover of fructose and glucose pools. Hexose loss from starch or starch plus lower molecular weight glucan pools was insufficient to account for nocturnal accumulation of malic acid. The apparent maximum catalytic capacity of pyrophosphate:6-phosphofructokinase (PPi-PFK) at 15 degrees C was about 16 times higher than the mean maximum rate of glycolysis that occurred to support malic acid accumulation in pineapple leaves at night and 12 times higher than the mean maximum rate of hexose turnover from all carbohydrate pools. The apparent maximum catalytic capacity of ATP-PFK at 15 degrees C was about 70% of the activity required to account for the mean maximal rate of hexose turnover from all carbohydrate pools if turnover were completely via glycolysis, and marginally sufficient to account for mean maximal rates of acidification. Therefore, at low night temperatures conducive to CAM and under subsaturating substrate concentrations, PPi-PFK activity, but not ATP-PFK activity, would be sufficient to support the rate of glycolytic carbohydrate processing required for acid accumulation. These data for pineapple establish that there are at least two types of CAM plants with respect to the nature of the carbohydrate reserve utilized to support nighttime CO(2) accumulation. The data further indicate that the glycolytic carbohydrate processing that supports acidification proceeds in different subcellular compartments in plants utilizing different carbohydrate reserves.

Journal Article↗
PubMed1965

PRELIMINARY ENZYMATIC EVENTS IN ASPARAGINE-DEPENDENT DENITRIFICATION BY PSEUDOMONAS PERFECTOMARINUS.

Best, Audrey N. (University of Georgia, Athens), and W. J. Payne. Preliminary enzymatic events in asparagine-dependent denitrification by Pseudomonas perfectomarinus. J. Bacteriol. 89:1051-1054. 1965.-The initial events leading to denitrification by Pseudomonas perfectomarinus grown anaerobically in the presence of NO(3) (-) were investigated. Conversion of asparagine to malic acid was demonstrated. The nicotinamide adenine dinucleotide phosphate-linked malic acid dehydrogenase in this bacterium was shown to have a dependence for a divalent cation. A transhydrogenase was demonstrated. Oxaloacetic acid, a likely intermediate in conversion of malic to pyruvic acid, was rapidly decarboxylated by enzymes in cell-free extracts. We were not able to show reversible formation of malic acid with oxaloacetic acid and reduced nicotinamide adenine dinucleotide phosphate, nor of oxaloacetic acid with pyruvic acid and CO(2).

Asparagine↗
PubMed1990

Low-dose almitrine bismesylate enhances hypoxic pulmonary vasoconstriction in closed-chest dogs.

The effect of almitrine bismesylate on the hypoxic pulmonary vasoconstrictor response was studied in six closed-chest dogs anesthetized with pentobarbital and paralyzed with pancuronium. The right lung was ventilated continuously with 100% O2; the left lung was ventilated either with 100% O2 ("hyperoxia") or with an hypoxic gas mixture ("hypoxia": end-tidal oxygen tension = 60.3 +/- 0.6 mm Hg). On two consecutive days, each dog received either almitrine (Vectarion, Servier Lab) or malic acid. Consecutive almitrine doses of 0.003, 0.03, 0.3, and 3.0 micrograms.kg-1.min-1, or the equivalent volumes of malic acid without almitrine, were administered intravenously as a constant peripheral infusion for 15 min. Percent blood flow to each lung was calculated based on a variation of the traditional shunt equation. The change in percent left lung blood flow (delta %QL-VA) increased significantly between the hypoxia-no drug and the hypoxia-almitrine (3.0 micrograms.kg-1.min-1) phase. No significant changes occurred during the other almitrine doses or the respective malic acid control phases. The change in arterial oxygen tension (delta PaO2) also increased significantly between the hypoxia-no drug and the hypoxia-almitrine (3.0 micrograms.kg-1.min-1) phase. No significant changes occurred during the other almitrine doses or the respective malic acid control phases. It is concluded that in dogs low-dose almitrine enhances hypoxic pulmonary vasoconstriction and that this enhancement is dose-related.

Almitrine↗
PubMed1992

Competitive Growth of Genetically Marked Malolactic-Deficient Lactobacillus plantarum in Cucumber Fermentations.

Procedures were developed for the differential enumeration of an added strain of Lactobacillus plantarum and indigenous lactic acid bacteria (LAB) during the fermentation of brined cucumbers. The added strain was an N,N-nitrosoguanidine-generated mutant that lacked the ability to produce CO(2) from malic acid (MDC). The MDC phenotype is desirable because CO(2) production from malic acid decarboxylation has been shown to contribute to bloater formation in fermented cucumbers. A basal medium containing malic acid and adjusted to pH 4.0 permitted growth of indigenous LAB (predominantly MDC), but not growth of the added MDC culture. Transformation of the MDC culture by electroporation with cloning vector pGK12 conferred chloramphenicol resistance, which permitted selective enumeration of this culture. The reversion frequency of the MDC mutation was determined by a fluctuation test to be less than 10. The level of retention of plasmid pGK12 was greater than 90% after 10 generations in cucumber juice medium at 32 degrees C. With the procedures developed, we were able to establish the ratio of MDC to MDC LAB that results in malic acid retention in fermentations of filter-sterilized cucumber juice and unsterilized whole cucumbers under specified conditions.

Journal Article↗
PubMed1989

Production of Leuconostoc oenos Biomass under pH Control.

Leuconostoc oenos was grown on apple juice-based media. The effect of pH control on metabolism and biomass production was studied. Without pH control, L. oenos acidified the apple juice media to approximately pH 3.6. More than 75% of the malic acid was used under these conditions, but less than half of the carbohydrates was assimilated. Under pH control, biomass yields increased by 60%; most of the malic acid was used, but high levels of unfermented carbohydrates remained. The addition of tomato juice, vitamins, nucleotides, Mn, and malic acid did not permit further increases in the cell counts; however, malic acid did induce further acidification. Growth without pH control favored a more homofermentative metabolism. Biomass production was higher in filter-sterilized apple juice media compared with that in the autoclaved media.

Journal Article↗