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PubMed2003

Human milk is a source of lactic acid bacteria for the infant gut.

OBJECTIVES: To investigate whether human breast milk contains potentially probiotic lactic acid bacteria, and therefore, whether it can be considered a synbiotic food. Study design Lactic acid bacteria were isolated from milk, mammary areola, and breast skin of eight healthy mothers and oral swabs and feces of their respective breast-fed infants. Some isolates (178 from each mother and newborn pair) were randomly selected and submitted to randomly amplified polymorphic DNA (RAPD) polymerase chain reaction analysis, and those that displayed identical RAPD patterns were identified by 16S rDNA sequencing. RESULTS: Within each mother and newborn pair, some rod-shaped lactic acid bacteria isolated from mammary areola, breast milk, and infant oral swabs and feces displayed identical RAPD profiles. All of them, independently from the mother and child pair, were identified as Lactobacillus gasseri. Similarly, among coccoid lactic acid bacteria from these different sources, some shared an identical RAPD pattern and were identified as Enterococcus faecium. In contrast, none of the lactic acid bacteria isolated from breast skin shared RAPD profiles with lactic acid bacteria of the other sources. CONCLUSIONS: Breast-feeding can be a significant source of lactic acid bacteria to the infant gut. Lactic acid bacteria present in milk may have an endogenous origin and may not be the result of contamination from the surrounding breast skin.

Breast↗
PubMed2000

Acid and bile tolerance of spore-forming lactic acid bacteria.

Criteria for screening probiotics such as bile tolerance and resistance to acids were studied with 13 spore-forming lactic acid producing bacteria. Different strains of Sporolactobacillus, Bacillus laevolacticus, Bacillus racemilacticus and Bacillus coagulans grown in MRS broth were subjected to low pH conditions (2, 2.5 and 3) and increasing bile concentrations. Among these microorganisms, Bacillus laevolacticus DSM 6475 and all Sporolactobacillus strains tested except Sporolactobacillus racemicus IAM 12395, were resistant to pH 3. Only Bacillus racemilacticus and Bacillus coagulans strains were tolerant to bile concentrations over 0.3% (w/v).

Bacillus↗
PubMed1996

Cerebrospinal fluid/serum lactic acid in Nigerian children with febrile convulsions.

Cerebrospinal fluid (CSF) and serum lactic acid levels were prospectively assayed in 42 children less than 5 years old with febrile convulsions who were divided into two groups for analytical purposes, irrespective of aetiology of pyrexia. One group (24 children) had brief febrile seizures and the remaining 18 children had prolonged febrile seizures. CSF and serum lactic acid values were obtained for brief and prolonged seizures. On admission, the mean CSF lactic acid was significantly higher (p < 0.05) in children with prolonged than with brief seizures, but the mean serum lactic acid was not significantly different between the two groups. Twelve of the 18 children (67%) with prolonged seizures and elevated CSF lactate had seizure recurrence. There were no recurrences of seizures in children with a brief initial seizure and low CSF lactate. CSF lactic acid is elevated in children with prolonged seizures and this may be useful in detecting those with a prolonged seizure where the history of the duration of the seizure is not clear. Prolonged seizure has been associated with the risk of recurrence and therefore such children with elevated CSF lactic acid levels might benefit from long-term anticonvulsant therapy.

Anticonvulsants↗
PubMed1997

The role of transport processes in survival of lactic acid bacteria. Energy transduction and multidrug resistance.

Lactic acid bacteria play an essential role in many food fermentation processes. They are anaerobic organisms which obtain their metabolic energy by substrate phosphorylation. In addition three secondary energy transducing processes can contribute to the generation of a proton motive force: proton/substrate symport as in lactic acid excretion, electrogenic precursor/product exchange as in malolactic and citrolactic fermentation and histidine/histamine exchange, and electrogenic uniport as in malate and citrate uptake in Leuconostoc oenos. In several of these processes additional H+ consumption occurs during metabolism leading to the generation of a pH gradient, internally alkaline. Lactic acid bacteria have also developed multidrug resistance systems. In Lactococcus lactis three toxin excretion systems have been characterized: cationic toxins can be excreted by a toxin/proton antiport system and by an ABC-transporter. This cationic ABC-transporter has surprisingly high structural and functional analogy with the human MDR1-(P-glycoprotein). For anions an ATP-driven ABC-like excretion systems exist.

ATP-Binding Cassette Transporters↗
PubMed1988

A pH Control System Based on Malate Decarboxylation for the Cultivation of Lactic Acid Bacteria.

Most species of lactic acid bacteria decarboxylate l-malate to lactate and CO(2) if an energy source such as glucose is present. A proton is taken up in the reaction, which prevents pH decreases in the growth medium caused by lactic acid production from glucose fermentation. MRS broth (pH 7.0) (Difco Laboratories) containing 10 mM glucose and various concentrations of l-malate (0, 25, 50, 75, and 100 mM) was used to cultivate Lactobacillus plantarum. After 72 h at 37 degrees C, all malate was decarboxylated and all glucose was fermented, with resultant final pH values of 4.5, 6.3, 6.9, 7.3, and 7.5, respectively. When d-malate (which cannot be decarboxylated) was substituted for l-malate, the final pH values were 4.5, 5.2, 5.6, 5.8, and 5.9. By varying the ratios of glucose to l-malate in the growth medium, it was possible to obtain pH values which were lower, the same, or higher than the initial pH values. In contrast, buffers such as phosphate only retard decreases in pH. l-Malate, when compared with K(2)PO(4) on an equal molar basis, provided greater resistance to decreases in pH. Higher specific growth rates were observed for L. plantarum and Leuconostoc mesenteroides when l-malate rather than K(2)PO(4) was incorporated into the growth medium.

Journal Article↗
PubMed2004

Lactic acid production with lactate dehydrogenase using the visible light sensitization of zinc porphyrin.

Lactic acid production with L-lactate dehydrogenase from Pig heart (LDH) and reduced methyl viologen produced by the visible light photosensitization of zinc tetrakis(4-methylpyridyl)porphyrin (ZnTMPyP) was investigated. When the sample solution containing triethanolamine as an electron-donating reagent, ZnTMPyP, methyl viologen as an electron carrier, pyruvic acid and LDH in potassium phosphate buffer (pH 7) was irradiated, lactic acid production was observed. After 240 min irradiation, the amount of lactic acid production and the yield of pyruvic acid to lactic acid were estimated to be 0.17 mmol dm(-3) and 17.0%, respectively.

Animals↗
PubMed1990

Enzymatic activity toward poly(L-lactic acid) implants.

Tissue reactions toward biodegradable poly(L-lactic acid) implants were monitored by studying the activity pattern of seven enzymes as a function of time: alkaline phosphatase, acid phosphatase, alpha-naphthylacetyl esterase, beta-glucuronidase, ATP-ase, NADH-reductase, and lactate dehydrogenase. Cell types were identified by their specific enzyme patterns, their morphology and location. Special attention was paid to the enzyme patterns of macrophages, fibroblasts and polymorphonuclear granulocytes (PMNs), being involved in foreign body reactions or inflammatory responses. One day after implantation, an influx of neutrophilic and eosinophilic granulocytes was observed, coinciding with activity of alkaline phosphatase (PMN's) and beta-glucuronidase (eosinophils). From day 3 on, macrophages containing ATP-ase, acid phosphatase and esterase could be observed. From day 7 on, lactate dehydrogenase, the enzyme normally involved in the conversion of lactic acid, and its coenzyme NADH-reductase were observed in macrophages and fibroblasts. These two enzymes demonstrated more activity than expected on basis of wound-healing reactions upon implantation of a nonbiodegradable, inert biomaterial (as, e.g., Teflon). It is concluded that the biodegradable poly (L-lactic acid) used in these implantation studies is tissue compatible, and evokes a foreign body reaction with minor macrophage and giant cell activity, as observed during this 3-week implantation period. Most enzyme patterns were simply due to a wound-healing reaction. The slightly increased levels of LDH and NADH suggest the release of lactic acid from the implant, and thus confirms the biodegradable nature of this polymer.

Animals↗
PubMed2004

Chemiluminescence biosensor system for lactic acid using natural animal tissue as recognition element.

A new method based on natural animal tissue porcine kidney as recognition element for chemiluminescence sensing of lactic acid is proposed in this paper. The principle for lactic acid sensing is that lactic acid is oxidized by oxygen under the catalysis of alpha-hydroxy acid oxidase in the tissue column to produce hydrogen peroxide, which can react with luminol in the presence of potassium ferricyanide to generate a CL signal. The experimental results show that the CL emission intensity was linear with lactic acid concentration in the range of 1-1000 micromol/L and the detection limit (3sigma) for lactic acid was 0.2 micromol/L. The biosensor could be used continuously for 6h with no significant changes in the response. More than 240 measurements were carried out during this time. A complete analysis, including sampling and washing, could be performed in 1.5 min with a relative standard deviation of 1.12% for 100 micromol/L lactic acid. The reproducibility among tissue columns was satisfactory (RSD among columns is less than 5%). The biosensor has been applied successfully to the analysis of lactic acid in plasma and milk samples.

Animals↗
PubMed2005

Transport mechanism for L-lactic acid in human myocytes using human prototypic embryonal rhabdomyosarcoma cell line (RD cells).

Monocarboxylate transporter (MCT), which cotransport L-lactic acid and protons across cell membranes, are important for regulation of muscle pH. However, it has not been demonstrated in detail whether MCT isoform contribute to the transport of L-lactic acid in skeletal muscle. The aim of this study was to characterize L-lactic acid transport using an human rhabdomyosarcoma (RD) cell line as a model of human skeletal muscle. mRNAs of MCT 1, 2 and 4 were found to be expressed in RD cells. The [14C] L-lactic acid uptake was concentration-dependent with a Km of 1.19 mM. This Km value was comparable to its Km values for MCT1 or MCT2. MCT1 mRNA was found to be present markedly greater than that MCT2. Therefore, MCT1 most probably acts on L-lactic acid uptake at RD cells. [14C] L-Lactic acid efflux in RD cells was inhibited by alpha-cyano-4-hydroxycinnamate (CHC) but not by butyric acid, a substrate of MCT1. Accordingly, MCT2 or MCT4 is responsible for L-lactic acid efflux by RD cells. MCT4 mRNA was found to be present significantly greater than that MCT2. We conclude that MCT1 is responsible for L-lactic acid uptake and L-lactic acid efflux is mediated by MCT4 in RD cells.

Base Sequence↗
PubMed2005

Reducing by-product formation in L-lactic acid fermentation by Rhizopus oryzae.

During L-lactic acid fermentation by Rhizopus oryzae, increasing the phosphate level in the fermentation medium from 0.1 g l(-1) to 0.6 g l(-1) KH2PO4 reduced the maximal concentration of L-lactic acid and fumaric acid from 85 g l(-1) to 71 g l(-1) and from 1.36 g l(-1) to 0.18 g l(-1), respectively; and it decreased the fermentation time from 72 h to 52 h. Phosphate at 0.40 g l(-1) KH2PO4 was suitable for both minimizing fumaric acid accumulation and benefiting L-lactic acid production.

Fermentation↗
PubMed2025

Targeting MondoA-TXNIP restores antitumour immunity in lactic-acid-induced immunosuppressive microenvironment.

In the tumour microenvironment, accumulated lactic acid (LA) promotes tumour immune evasion by facilitating regulatory T cell (Treg) immunosuppressive function and restraining CD8+ T cell cytotoxicity, but the underlying mechanism remains elusive. Here we report that transcriptional factor MondoA-induced thioredoxin interacting protein (TXNIP) transcription is a common feature of both Treg and CD8+ T cells in response to lactic acid. In contrast to reduction in immunosuppressive capacity in MondoA-deficient Treg cells, loss of MondoA enhanced CD8+ T cell cytotoxic function in the lactic-acid-induced immunosuppressive microenvironment, by restoring glucose uptake and glycolysis. Mechanistically, lactic acid relied on sentrin/SUMO-specific protease 1 (SENP1) to stimulate the MondoA-TXNIP axis, which impaired TCR/CD28-signal-induced CD8+ T cell activation. Importantly, targeting the MondoA-TXNIP axis potentiated antitumour immunity in multiple cancer types and synergized with anti-PD-1 therapy to promote effective T cell responses in colorectal cancer. Our results demonstrate that the MondoA-TXNIP axis is a promising therapeutic target for improving cancer immunotherapy.

Tumor Microenvironment↗
PubMed2004

Effects of L-glutamate/D-aspartate and monensin on lactic acid production in retina and cultured retinal Müller cells.

We have investigated the dependence of the rate of lactic acid production on the rate of Na(+) entry in cultured transformed rat Müller cells and in normal and dystrophic (RCS) rat retinas that lack photoreceptors. To modulate the rate of Na(+) entry, two approaches were employed: (i) the addition of L-glutamate (D-aspartate) to stimulate coupled uptake of Na(+) and the amino acid; and (ii) the addition of monensin to enhance Na(+) exchange. Müller cells produced lactate aerobically and anaerobically at high rates. Incubation of the cells for 2-4 h with 0.1-1 mM L-glutamate or D-aspartate did not alter the rate of production of lactate. ATP content in the cells at the end of the incubation period was unchanged by addition of L-glutamate or D-aspartate to the incubation media. Na(+)-dependent L-glutamate uptake was observed in the Müller cells, but the rate of uptake was very low relative to the rate of lactic acid production. Ouabain (1 mM) decreased the rate of lactic acid production by 30-35% in Müller cells, indicating that energy demand is enhanced by the activity of the Na(+)-K(+) pump or depressed by its inhibition. Incubation of Müller cells with 0.01 mM monensin, a Na(+) ionophore, caused a twofold increase in aerobic lactic acid production, but monensin did not alter the rate of anaerobic lactic acid production. Aerobic ATP content in cells incubated with monensin was not different from that found in control cells, but anaerobic ATP content decreased by 40%. These results show that Na(+)-dependent L-glutamate/D-aspartate uptake by cultured retinal Müller cells causes negligible changes in lactic acid production, apparently because the rates of uptake are low relative to the basal rates of lactic acid production. In contrast, the marked stimulation of aerobic lactic acid production caused by monensin opening Na(+) channels shows that glycolysis is an effective source of ATP production for the Na(+)-K(+) ATPase. A previous report suggests that coupled Na(+)-L-glutamate transport stimulates glycolysis in freshly dissociated salamander Müller cells by activation of glutamine synthetase. The Müller cell line used in this study does not express glutamine synthetase; consequently these cells could only be used to examine the linkage between Na(+) entry and the Na(+) pump. As normal and RCS retinas express glutamine synthetase, the role of this enzyme was examined by coapplication of L-glutamate and NH(4) (+) in the presence and absence of methionine sulfoximine, an inhibitor of glutamine synthetase. In normal retinas, neither the addition of L-glutamate alone or together with NH(4) (+) caused a significant change in the glycolytic rate, an effect linked to the low rate of uptake of this amino acid relative to the basal rate of retinal glycolysis. However, incubation of the RCS retinas in media containing L-glutamate and NH(4)(+) did produce a small (15%) increase in the rate of glycolysis above the rate found with L-glutamate alone and controls. It is unlikely that this increase was the result of conversion of L-glutamate to L-glutamine, as it was not suppressed by inhibition of glutamine synthetase with 5 mm methionine sulfoximine. It appears that the magnitude of Müller cell glycolysis required to sustain the coupled transport of Na(+) and L-glutamate and synthesis of L-glutamine is small relative to the basal glycolytic activity in a rat retina.

Animals↗
PubMed2005

Polyphasic characterization of the lactic acid bacteria in kefir.

The lactic acid bacteria of kefir were isolated and characterized using phenotypical, biochemical, and genotypical methods. Polyphasic analyses of results permitted the identification of the microflora to the strain level. The genus Lactobacillus was represented by the species Lb. kefir and Lb. kefiranofaciens. Both subspecies of Lactococcus lactis (lactis and cremoris) were isolated. Leuconostoc mesenteroides subsp. cremoris was also found. The kefir studied contained few species of lactic acid bacteria but showed a high number of different strains. We found that the polyphasic analysis approach increases the confidence in strain determination. It helped confirm strain groupings and it showed that it could have an impact on the phylogeny of the strains.

Cultured Milk Products↗
PubMedDate not supplied

Effect of ethanol on lactic acid production by exercised normal muscle.

Several studies have suggested that muscle lactic acid production is defective in alcoholic myopathy. However, normal controls have not been evaluated. To study the effects of ethanol on the production of lactic acid in normal exercised muscle, oral ethanol (1 g per kg body weight, 20% v/v) was given to eight nonalcoholic subjects. Forearm ischemic exercise with a total work load of 7.2 kg-m/min was performed just before and 90 min after ingestion of ethanol. At the time of exercise, the serum ethanol level was 95.7 +/- 15.1 mg% (mean +/- SD). Resting serum lactic acid was significantly higher after ingestion of ethanol (15.7 +/- 4.5 mg%) than before (8.5 +/- 4.7 mg%). Lactic acid generation with ischemic exercise was significantly lower after ethanol ingestion. The mean peak serum lactic acid level (expressed as percentage elevation above resting) was 330.5 +/- 118.2% before and 127.9 +/- 75.1% after (p less than .05). These results indicate that a single oral dose of ethanol decreases lactic acid production by exercised muscle in normal subjects.

Adult↗
PubMed2005

Direct fermentation of potato starch wastewater to lactic acid by Rhizopus oryzae and Rhizopus arrhizus.

The biochemical kinetic of direct fermentation for lactic acid production by fungal species of Rhizopus arrhizus 3,6017 and Rhizopus oryzae 2,062 was studied with respect to growth pH, temperature and substrate. The direct fermentation was characterized by starch hydrolysis, accumulation of reducing sugar, and production of lactic acid and fungal biomass. Starch hydrolysis, reducing sugar accumulation, biomass formation and lactic acid production were affected with the variations in pH, temperature, and starch source and concentration. A growth condition with starch concentration approximately 20 g/l at pH 6.0 and 30 degrees C was favourable for both starch saccharification and lactic acid fermentation, resulting in lactic acid yield of 0.87-0.97 g/g starch associated with 1.5-2.0 g/l fungal biomass produced in 36 h fermentation. R. arrhizus 3,6017 had a higher capacity to produce lactic acid, while R. oryzae 2,062 produced more fungal biomass under similar conditions.

Industrial Microbiology↗
PubMed1964

SUBSTITUTION OF MANGANESE FOR TOMATO JUICE IN THE CULTIVATION OF LACTIC ACID BACTERIA.

Tomato juice was separated by chemical and physical methods into various active fractions, as measured by growth response and acid production by numerous lactic acid bacteria. Incineration of the treated extracts with little apparent loss in activity established the fact that the stimulatory component was of inorganic composition. Of the various cations tested, manganese was the only element that produced biological activity comparable to that of the original extract. Of the 71 strains of lactic acid bacteria tested, 63 strains showed a definite requirement for manganese or tomato juice.

Culture Media↗