Artykuły w czasopismach na temat „Lactic acid – Metabolism”
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Pin, Carmen, Gonzalo D. García de Fernando i Juan A. Ordóñez. "Effect of Modified Atmosphere Composition on the Metabolism of Glucose by Brochothrix thermosphacta". Applied and Environmental Microbiology 68, nr 9 (wrzesień 2002): 4441–47. http://dx.doi.org/10.1128/aem.68.9.4441-4447.2002.
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ABSTRACT The influence of atmosphere composition on the metabolism of Brochothrix thermosphacta was studied by analyzing the consumption of glucose and the production of ethanol, acetic and lactic acids, acetaldehyde, and diacetyl-acetoin under atmospheres containing different combinations of carbon dioxide and oxygen. When glucose was metabolized under oxygen-free atmospheres, lactic acid was one of the main end products, while under atmospheres rich in oxygen mainly acetoin-diacetyl was produced. The proportions of the total consumed glucose used for the production of acetoin (aerobic metabolism) and lactic acid (anaerobic metabolism) were used to decide whether aerobic or anaerobic metabolism predominated at a given atmosphere composition. The boundary conditions between dominantly anaerobic and aerobic metabolisms were determined by logistic regression. The metabolism of glucose by B. thermosphacta was influenced not only by the oxygen content of the atmosphere but also by the carbon dioxide content. At high CO2 percentages, glucose metabolism remained anaerobic under greater oxygen contents.
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Oh, Euhlim. "Dynamic Modeling of Lactic Acid Fermentation Metabolism with Lactococcus lactis". Journal of Microbiology and Biotechnology 21, nr 2 (luty 2011): 162–69. http://dx.doi.org/10.4014/jmb.1007.07066.
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Hugenholtz, Jeroen. "Citrate metabolism in lactic acid bacteria". FEMS Microbiology Reviews 12, nr 1-3 (wrzesień 1993): 165–78. http://dx.doi.org/10.1111/j.1574-6976.1993.tb00017.x.
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Miller, O. Neal, i Gaetano Bazzano. "PROPANEDIOL METABOLISM AND ITS RELATION TO LACTIC ACID METABOLISM*". Annals of the New York Academy of Sciences 119, nr 3 (16.12.2006): 957–73. http://dx.doi.org/10.1111/j.1749-6632.1965.tb47455.x.
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Porro, Danilo, Michele M. Bianchi, Luca Brambilla, Rossella Menghini, Davide Bolzani, Vittorio Carrera, Jefferson Lievense i in. "Replacement of a Metabolic Pathway for Large-Scale Production of Lactic Acid from Engineered Yeasts". Applied and Environmental Microbiology 65, nr 9 (1.09.1999): 4211–15. http://dx.doi.org/10.1128/aem.65.9.4211-4215.1999.
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ABSTRACT Interest in the production of l-(+)-lactic acid is presently growing in relation to its applications in the synthesis of biodegradable polymer materials. With the aim of obtaining efficient production and high productivity, we introduced the bovinel-lactate dehydrogenase gene (LDH) into a wild-type Kluyveromyces lactis yeast strain. The observed lactic acid production was not satisfactory due to the continued coproduction of ethanol. A further restructuring of the cellular metabolism was obtained by introducing the LDH gene into aK. lactis strain in which the unique pyruvate decarboxylase gene had been deleted. With this modified strain, in which lactic fermentation substituted completely for the pathway leading to the production of ethanol, we obtained concentrations, productivities, and yields of lactic acid as high as 109 g liter−1, 0.91 g liter−1 h−1, and 1.19 mol per mole of glucose consumed, respectively. The organic acid was also produced at pH levels lower than those usual for bacterial processes.
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Gänzle, Michael G. "Lactic metabolism revisited: metabolism of lactic acid bacteria in food fermentations and food spoilage". Current Opinion in Food Science 2 (kwiecień 2015): 106–17. http://dx.doi.org/10.1016/j.cofs.2015.03.001.
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Osborne, J. P., R. Mira de Orduña, G. J. Pilone i S. Q. Liu. "Acetaldehyde metabolism by wine lactic acid bacteria". FEMS Microbiology Letters 191, nr 1 (październik 2000): 51–55. http://dx.doi.org/10.1111/j.1574-6968.2000.tb09318.x.
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de Vos, Willem M., Michiel Kleerebezem i Oscar P. Kuipers. "Lactic acid bacteria — Genetics, metabolism and application". FEMS Microbiology Reviews 29, nr 3 (sierpień 2005): 391. http://dx.doi.org/10.1016/j.fmrre.2005.05.001.
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DEVOS, W., M. KLEEREBEZEM i O. KUIPERS. "Lactic acid bacteria – Genetics, metabolism and application". FEMS Microbiology Reviews 29, nr 3 (sierpień 2005): 391. http://dx.doi.org/10.1016/j.femsre.2005.05.001.
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Matejčeková, Zuzana, Elena Dujmić, Denisa Liptáková i Ľubomír Valík. "Modeling of lactic acid fermentation of soy formulation with Lactobacillus plantarum HM1". Food Science and Technology International 25, nr 2 (4.10.2018): 141–49. http://dx.doi.org/10.1177/1082013218803257.
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Lactic acid bacteria alone or with special adjunct probiotic strains are inevitable for the preparation of various specific functional foods. Moreover, because of their growth and metabolism, the final products are preserved for a certain time. Thus, growth dynamics of the lactic acid bacteria of the Fresco DVS 1010 culture ( Lactococcus lactis spp. lactis, Lactococcus lactis spp. cremoris, Streptococcus salivarius spp. thermophilus) during liquid-state fermentation of soya mashes and pH values within the process were analyzed in this study. Although milk is the most typical growth medium for the lactic acid bacteria, presumable viable counts of Fresco culture reached levels 109 CFU ml−1 after 8 h, representing 2–3 log increase in comparison to initial state (specific growth rates ranged from 1.06 to 1.64 h−1). After 21 days of storage period, the pH levels in the products were reduced to 4.50–4.70, representing a decrease of about 1.5–1.7 units. All prepared soybean products contained detectable amounts of raffinose-series oligosaccharides (0.25–0.68 g per 100 g) that were reduced in average by about 30.5% during period of 21 days.
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Fischer, Karin, Petra Hoffmann, Simon Voelkl, Norbert Meidenbauer, Julia Ammer, Matthias Edinger, Eva Gottfried i in. "Inhibitory effect of tumor cell–derived lactic acid on human T cells". Blood 109, nr 9 (25.01.2007): 3812–19. http://dx.doi.org/10.1182/blood-2006-07-035972.
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Abstract A characteristic feature of tumors is high production of lactic acid due to enhanced glycolysis. Here, we show a positive correlation between lactate serum levels and tumor burden in cancer patients and examine the influence of lactic acid on immune functions in vitro. Lactic acid suppressed the proliferation and cytokine production of human cytotoxic T lymphocytes (CTLs) up to 95% and led to a 50% decrease in cytotoxic activity. A 24-hour recovery period in lactic acid–free medium restored CTL function. CTLs infiltrating lactic acid–producing multicellular tumor spheroids showed a reduced cytokine production. Pretreatment of tumor spheroids with an inhibitor of lactic acid production prevented this effect. Activated T cells themselves use glycolysis and rely on the efficient secretion of lactic acid, as its intracellular accumulation disturbs their metabolism. Export by monocarboxylate transporter-1 (MCT-1) depends on a gradient between cytoplasmic and extracellular lactic acid concentrations and consequently, blockade of MCT-1 resulted in impaired CTL function. We conclude that high lactic acid concentrations in the tumor environment block lactic acid export in T cells, thereby disturbing their metabolism and function. These findings suggest that targeting this metabolic pathway in tumors is a promising strategy to enhance tumor immunogenicity.
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Maryati, Yati, Lilis Nuraida i Ratih Dewanti Hariyadi. "Production of Organic Acid and Short-Chain Fatty Acids (SCFA) from Lactic Acid Bacteria Isolate on Oligosaccharide Media". Jurnal Kimia Sains dan Aplikasi 24, nr 6 (11.08.2021): 213–21. http://dx.doi.org/10.14710/jksa.24.6.213-221.
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The growth of microorganisms in food, one of which is lactic acid bacteria (LAB), can produce metabolites beneficial to health. It is essential to study the results of LAB metabolism to improve the quality of a functional food product. This study aimed to evaluate the isolates Lactobacillus acidophilus FNCC 0051 and Lactobacillus rhamnosus R23 to metabolize oligosaccharides as a carbon source so that the final fermentation product can benefit health especially in lowering cholesterol. In vitro testing was carried out on MRS media with or without oligosaccharides, either singly or in a combination consisting of galactooligosaccharides (GOS), fructooligosaccharides (FOS), inulin (IN), inulin hydrolyzate (HI), or their combination as prebiotics by adding 0.3 % oxbile (bile salt) and inoculated with 1% v/v LAB isolate culture and incubated at 37°C for 24 hours. The results showed that the main product of oligosaccharide metabolism by L. acidophilus FNCC 0051 and L. rhamnosus R23 produced several organic acids (lactic acid), including short-chain fatty acids (SCFA) (acetic acid, propionic acid, and butyric acid). The single and combined carbon sources affected the proportion of lactic acid and acetic acid produced by L. acidophilus FNCC0051 (p<0.05). However, they did not affect the proportions of propionic acid and butyric acid. While in L. rhamnosus R23 (p<0.05), the presence of a single carbon source significantly affected the proportions of lactic acid, acetic acid, propionic acid, and butyric acid, while the combination of oligosaccharides affected the proportions of lactic acid and butyric acid produced. SCFA is the main product of prebiotic metabolism, but the characteristics of the acid produced have not been identified. The fermentation pattern is thought to be related to molecular weight, chain length, and oligosaccharide structure. Short-chain molecules, such as FOS generally ferment more rapidly than long-chain molecules such as inulin. The results of this study indicate that both isolates can be used as probiotics in the development of symbiotic products with the addition of oligosaccharides, which have a physiological effect in lowering cholesterol levels.
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Smetanková, Jana, Zuzana Hladíková, František Valach, Michaela Zimanová, Zlatica Kohajdová, Gabriel Greif i Mária Greifová. "Influence of aerobic and anaerobic conditions on the growth and metabolism of selected strains of Lactobacillus plantarum". Acta Chimica Slovaca 5, nr 2 (1.11.2012): 204–10. http://dx.doi.org/10.2478/v10188-012-0031-1.
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Abstract Three wild strains of Lactobacillus plantarum were investigated for their growth and ability to produce lactic acid, acetic acid and ethanol under aerobic and anaerobic conditions. They were tested at three different temperatures (30 °C, 37 °C and 45 °C). The growth of lactobacilli was studied by measuring optical density (OD) at λ = 600 nm and pH value at the following times. With increasing temperature difference of cell yield was observed. The final cell yield under aerobic conditions was higher. Organic acids and ethanol were analysed using an HPLC RID method. Formation of lactic acid (as the major metabolite) was the slowest during cultivation at 30 °C, but the final amount of lactic acid showed the highest values. Concentrations of metabolites produced by lactobacilli after 48th hours of cultivation were: 9.18-11.48 g.dm-3 (lactic acid), 0.84-1.65 g.dm-3 (acetic acid) and 2.51-4.03 g.dm-3 (ethanol). No significant differences (p = 0.05) were found in production of lactic acid and ethanol by different bacterial strains under aerobic and anaerobic conditions. Statistically significant differences (p = 0.05) were observed in production of acetic acid by 2L2 under aerobic and anaerobic conditions and for production of ethanol under anaerobic conditions by strains 1L5 and 2L2.
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Iwami, Y., S. Hata, N. Takahashi i T. Yamada. "Difference in Amounts between Titratable Acid and Total Carboxylic Acids Produced by Oral Streptococci during Sugar Metabolism". Journal of Dental Research 68, nr 1 (styczeń 1989): 16–19. http://dx.doi.org/10.1177/00220345890680010101.
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The acid produced by the resting cells of Streptococcus mutans NCTC 10449 and HS 6 and S. sanguis ATCC 10556 during sugar metabolism was estimated with a pH-stat and a carboxylic acid analyzer. Lactic, formic, acetic, pyruvic, and carbonic acids were detected in the reaction mixtures, but propionic, citric, succinic, iso-butyric, butyric, iso-valeric, and valeric acids were not detected. The amount of titratable acid estimated by alkaline titration with the pH-stat was larger than the amount of total carboxylic acids estimated with the carboxylic acid analyzer. The difference in quantity between the titratable and the total carboxylic acids increased significantly with an increase in the period of incubation with sugar. Moreover, the value of the alkaline titration of standard lactic, formic, acetic, and pyruvic acids was equal to the amount analyzed with the carboxylic acid analyzer. The results indicated that these two streptococci produced not only these carboxylic acids but also other acid(s), possibly non-carboxylic acid(s), during their sugar metabolism.
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Kobayashi, Jyumpei. "d-Amino Acids and Lactic Acid Bacteria". Microorganisms 7, nr 12 (12.12.2019): 690. http://dx.doi.org/10.3390/microorganisms7120690.
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Proteins are composed of l-amino acids except for glycine, which bears no asymmetric carbon atom. Accordingly, researchers have studied the function and metabolism of l-amino acids in living organisms but have paid less attention to the presence and roles of their d-enantiomers. However, with the recent developments in analytical techniques, the presence of various d-amino acids in the cells of various organisms and the importance of their roles have been revealed. For example, d-serine (d-Ser) and d-aspartate (d-Asp) act as neurotransmitters and hormone-like substances, respectively, in humans, whereas some kinds of d-amino acids act as a biofilm disassembly factor in bacteria. Interestingly, lactic acid bacteria produce various kinds of d-amino acids during fermentation, and many d-amino acids taste sweet, compared with the corresponding l-enantiomers. The influence of d-amino acids on human health and beauty has been reported in recent years. These facts suggest that the d-amino acids produced by lactic acid bacteria are important in terms of the taste and function of lactic-acid-fermented foods. Against this background, unique d-amino-acid-metabolizing enzymes have been searched for and observed in lactic acid bacteria. This review summarizes and introduces the importance of various d-amino acids in this regard.
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Pohanka, Miroslav. "D-Lactic Acid as a Metabolite: Toxicology, Diagnosis, and Detection". BioMed Research International 2020 (18.06.2020): 1–9. http://dx.doi.org/10.1155/2020/3419034.
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Two enantiomers of lactic acid exist. While L-lactic acid is a common compound of human metabolism, D-lactic acid is produced by some strains of microorganism or by some less relevant metabolic pathways. While L-lactic acid is an endogenous compound, D-lactic acid is a harmful enantiomer. Exposure to D-lactic acid can happen by various ways including contaminated food and beverages and by microbiota during some pathological states like short bowel syndrome. The exposure to D-lactic acid cannot be diagnosed because the common analytical methods are not suitable for distinguishing between the two enantiomers. In this review, pathways for D-lactic acid, pathological processes, and diagnostical and analytical methods are introduced followed by figures and tables. The current literature is summarized and discussed.
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Brin, Myron. "THE SYNTHESIS AND METABOLISM OF LACTIC ACID ISOMERS". Annals of the New York Academy of Sciences 119, nr 3 (16.12.2006): 942–56. http://dx.doi.org/10.1111/j.1749-6632.1965.tb47454.x.
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London, Jack. "Uncommon pathways of metabolism among lactic acid bacteria". FEMS Microbiology Letters 87, nr 1-2 (wrzesień 1990): 103–12. http://dx.doi.org/10.1111/j.1574-6968.1990.tb04882.x.
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Pastink, Margreet I., Bas Teusink, Pascal Hols, Sanne Visser, Willem M. de Vos i Jeroen Hugenholtz. "Genome-Scale Model of Streptococcus thermophilus LMG18311 for Metabolic Comparison of Lactic Acid Bacteria". Applied and Environmental Microbiology 75, nr 11 (3.04.2009): 3627–33. http://dx.doi.org/10.1128/aem.00138-09.
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ABSTRACT In this report, we describe the amino acid metabolism and amino acid dependency of the dairy bacterium Streptococcus thermophilus LMG18311 and compare them with those of two other characterized lactic acid bacteria, Lactococcus lactis and Lactobacillus plantarum. Through the construction of a genome-scale metabolic model of S. thermophilus, the metabolic differences between the three bacteria were visualized by direct projection on a metabolic map. The comparative analysis revealed the minimal amino acid auxotrophy (only histidine and methionine or cysteine) of S. thermophilus LMG18311 and the broad variety of volatiles produced from amino acids compared to the other two bacteria. It also revealed the limited number of pyruvate branches, forcing this strain to use the homofermentative metabolism for growth optimization. In addition, some industrially relevant features could be identified in S. thermophilus, such as the unique pathway for acetaldehyde (yogurt flavor) production and the absence of a complete pentose phosphate pathway.
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Luesink, Evert J., Oscar P. Kuipers i Willem M. de Vos. "Regulation of the carbohydrate metabolism in Lactococcus lactis and other lactic acid bacteria". Le Lait 78, nr 1 (1998): 69–76. http://dx.doi.org/10.1051/lait:199819.
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Gao, Yuting, Hao Zhou, Gege Liu, Junlu Wu, Yi Yuan i Anquan Shang. "Tumor Microenvironment: Lactic Acid Promotes Tumor Development". Journal of Immunology Research 2022 (12.06.2022): 1–8. http://dx.doi.org/10.1155/2022/3119375.
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Lactic acid is a “metabolic waste” product of glycolysis that is produced in the body. However, the role of lactic acid in the development of human malignancies has gained increasing interest lately as a multifunctional small molecule chemical. There is evidence that tumor cells may create a large amount of lactic acid through glycolysis even when they have abundant oxygen. Tumor tissues have a higher quantity of lactic acid than normal tissues. Lactic acid is required for tumor development. Lactate is an immunomodulatory chemical that affects both innate and adaptive immune cells’ effector functions. In immune cells, the lactate signaling pathway may potentially serve as a link between metabolism and immunity. Lactate homeostasis is significantly disrupted in the TME. Lactate accumulation results in acidosis, angiogenesis, immunosuppression, and tumor cell proliferation and survival, all of which are deleterious to health. Thus, augmenting anticancer immune responses by lactate metabolism inhibition may modify lactate levels in the tumor microenvironment. This review will evaluate the role of lactic acid in tumor formation, metastasis, prognosis, treatment, and histone modification. Our findings will be of considerable interest to readers, particularly those engaged in the therapeutic treatment of cancer patients. Treatments targeting the inhibition of lactate synthesis and blocking the source of lactate have emerged as a potential new therapeutic option for oncology patients. Additionally, lactic acid levels in the plasma may serve as biomarkers for disease stage and may be beneficial for evaluating therapy effectiveness in individuals with tumors.
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Van der Meulen, Roel, Tom Adriany, Kristof Verbrugghe i Luc De Vuyst. "Kinetic Analysis of Bifidobacterial Metabolism Reveals a Minor Role for Succinic Acid in the Regeneration of NAD+ through Its Growth-Associated Production". Applied and Environmental Microbiology 72, nr 8 (sierpień 2006): 5204–10. http://dx.doi.org/10.1128/aem.00146-06.
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ABSTRACT Several strains belonging to the genus Bifidobacterium were tested to determine their abilities to produce succinic acid. Bifidobacterium longum strain BB536 and Bifidobacterium animalis subsp. lactis strain Bb 12 were kinetically analyzed in detail using in vitro fermentations to obtain more insight into the metabolism and production of succinic acid by bifidobacteria. Changes in end product formation in strains of Bifidobacterium could be related to the specific rate of sugar consumption. When the specific sugar consumption rate increased, relatively more lactic acid and less acetic acid, formic acid, and ethanol were produced, and vice versa. All Bifidobacterium strains tested produced small amounts of succinic acid; the concentrations were not more than a few millimolar. Succinic acid production was found to be associated with growth and stopped when the energy source was depleted. The production of succinic acid contributed to regeneration of a small part of the NAD+, in addition to the regeneration through the production of lactic acid and ethanol.
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Filannino, Pasquale, Marco Gobbetti, Maria De Angelis i Raffaella Di Cagno. "Hydroxycinnamic Acids Used as External Acceptors of Electrons: an Energetic Advantage for Strictly Heterofermentative Lactic Acid Bacteria". Applied and Environmental Microbiology 80, nr 24 (26.09.2014): 7574–82. http://dx.doi.org/10.1128/aem.02413-14.
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ABSTRACTThe metabolism of hydroxycinnamic acids by strictly heterofermentative lactic acid bacteria (19 strains) was investigated as a potential alternative energy route.Lactobacillus curvatusPE5 was the most tolerant to hydroxycinnamic acids, followed by strains ofWeissellaspp.,Lactobacillus brevis,Lactobacillus fermentum, andLeuconostoc mesenteroides, for which the MIC values were the same. The highest sensitivity was found forLactobacillus rossiaestrains. During growth in MRS broth, lactic acid bacteria reduced caffeic,p-coumaric, and ferulic acids into dihydrocaffeic, phloretic, and dihydroferulic acids, respectively, or decarboxylated hydroxycinnamic acids into the corresponding vinyl derivatives and then reduced the latter compounds to ethyl compounds. Reductase activities mainly emerged, and the activities of selected strains were further investigated in chemically defined basal medium (CDM) under anaerobic conditions. The end products of carbon metabolism were quantified, as were the levels of intracellular ATP and the NAD+/NADH ratio. Electron and carbon balances and theoretical ATP/glucose yields were also estimated. When CDM was supplemented with hydroxycinnamic acids, the synthesis of ethanol decreased and the concentration of acetic acid increased. The levels of these metabolites reflected on the alcohol dehydrogenase and acetate kinase activities. Overall, some biochemical traits distinguished the common metabolism of strictly heterofermentative strains: main reductase activity toward hydroxycinnamic acids, a shift from alcohol dehydrogenase to acetate kinase activities, an increase in the NAD+/NADH ratio, and the accumulation of supplementary intracellular ATP. Taken together, the above-described metabolic responses suggest that strictly heterofermentative lactic acid bacteria mainly use hydroxycinnamic acids as external acceptors of electrons.
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Abbott, Derek A., Erwin Suir, Giang-Huong Duong, Erik de Hulster, Jack T. Pronk i Antonius J. A. van Maris. "Catalase Overexpression Reduces Lactic Acid-Induced Oxidative Stress in Saccharomyces cerevisiae". Applied and Environmental Microbiology 75, nr 8 (27.02.2009): 2320–25. http://dx.doi.org/10.1128/aem.00009-09.
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ABSTRACT Industrial production of lactic acid with the current pyruvate decarboxylase-negative Saccharomyces cerevisiae strains requires aeration to allow for respiratory generation of ATP to facilitate growth and, even under nongrowing conditions, cellular maintenance. In the current study, we observed an inhibition of aerobic growth in the presence of lactic acid. Unexpectedly, the cyb2Δ reference strain, used to avoid aerobic consumption of lactic acid, had a specific growth rate of 0.25 h−1 in anaerobic batch cultures containing lactic acid but only 0.16 h−1 in identical aerobic cultures. Measurements of aerobic cultures of S. cerevisiae showed that the addition of lactic acid to the growth medium resulted in elevated levels of reactive oxygen species (ROS). To reduce the accumulation of lactic acid-induced ROS, cytosolic catalase (CTT1) was overexpressed by replacing the native promoter with the strong constitutive TPI1 promoter. Increased activity of catalase was confirmed and later correlated with decreased levels of ROS and increased specific growth rates in the presence of high lactic acid concentrations. The increased fitness of this genetically modified strain demonstrates the successful attenuation of additional stress that is derived from aerobic metabolism and may provide the basis for enhanced (micro)aerobic production of organic acids in S. cerevisiae.
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Jodłowski, Grzegorz S., i Edyta Strzelec. "Use of glycerol waste in lactic acid bacteria metabolism for the production of lactic acid: State of the art in Poland". Open Chemistry 19, nr 1 (1.01.2021): 998–1008. http://dx.doi.org/10.1515/chem-2021-0073.
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Abstract Lactic acid is a naturally existing organic acid, which may be used in many different branches of industrial application. It can be made in the sugar fermentation process from renewable raw lactic acid, which is an indispensable raw material, including in the agricultural, food, and pharmaceutical industries. It is an ecological product that has enjoyed great popularity in recent years. In 2010, the US Department of Energy published a report about lactic acid to be a potential building element for future technology, whose demand grows year by year. The lactic acid molecule naturally exists in plants, microorganisms, and animals and can also be produced by carbohydrate fermentation or chemical synthesis from coal, petroleum products, and natural gas. In industry, lactic acid can be produced by chemical synthesis or fermentation. Although racemic lactic acid is always produced chemically from petrochemical sources, the optically pure L(+) – or D(−) – lactic acid forms can be obtained by microbial fermentation of renewable resources when an appropriate microorganism is selected. Depending on the application, one form of optically pure LA is preferred over the other. Additionally, microbial fermentation offers benefits including cheap renewable substrates, low production temperatures, and low energy consumption. Due to these advantages, the most commonly used biotechnological production process with the use of biocatalysts, i.e., lactic acid bacteria. The cost of raw materials is one of the major factors in the economic production of lactic acid. As substrate costs cannot be reduced by scaling up the process, extensive research is currently underway to find new substrates for the production of LA. These searches include starch raw materials, lignocellulosic biomass, as well as waste from the food and refining industries. Here, the greatest attention is still drawn to molasses and whey as the largest sources of lactose, vitamins, and carbohydrates, as well as glycerol – a by-product of the biodiesel component production process. Focusing on the importance of lactic acid and its subsequent use as a product, but also a valuable raw material for polymerization (exactly to PLA), this review summarizes information about the properties and applications of lactic acid, as well as about its production and purification processes. An industrial installation for the production of lactic acid is only planned to be launched in Poland. As of today, there is no commercial-scale production of this bio-raw material. Thus, there is great potential for the application of the lactic acid production technology and research should be carried out on its development.
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Shah, Ira. "Lactic Acidosis in Children – A Varied Presentation". Journal of Pediatric Intensive Care 06, nr 03 (1.12.2016): 206–8. http://dx.doi.org/10.1055/s-0036-1596065.
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AbstractPrimary lactic acidemias represent a family of disorders of pyruvate metabolism or defects in the respiratory chain. However, lactic acidosis may also be seen in metabolic disorders such as organic acidemias, urea cycle defects, and fatty acid oxidation defects, which can be easily excluded by serum ammonia estimation, urinary organic acid estimation, and quantification of plasma amino acids. The classical presentation of a patient with primary lactic acidemia is growth retardation, ataxia, stroke, and increased lactic acid levels in the blood and cerebrospinal fluid. Patients may also present with cerebral edema, acute rhabdomyolysis, cardiac arrhythmias, cardiomyopathy, coma, and neurodegeneration. We present three cases of lactic acidemia with varied presentation. The first child presented at 5 years with recurrent hematemesis with hypoglycemia. The second child presented at 11 years of age with recurrent episodes of unconsciousness. The third child presented at one and a half months with convulsions.
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Kilstrup, Mogens, Karin Hammer, Peter Ruhdal Jensen i Jan Martinussen. "Nucleotide metabolism and its control in lactic acid bacteria". FEMS Microbiology Reviews 29, nr 3 (sierpień 2005): 555–90. http://dx.doi.org/10.1016/j.fmrre.2005.04.006.
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Doi, Yuki. "Glycerol metabolism and its regulation in lactic acid bacteria". Applied Microbiology and Biotechnology 103, nr 13 (8.05.2019): 5079–93. http://dx.doi.org/10.1007/s00253-019-09830-y.
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Indrayanti, Laily, i Harjo Mulyono. "PROFIL ASAM LAKTAT PENDERITA DIABETES MELLITUS TERKENDALI (KONTROL) DAN TIDAK TERKENDALI (KONTROL)". INDONESIAN JOURNAL OF CLINICAL PATHOLOGY AND MEDICAL LABORATORY 14, nr 3 (16.03.2018): 97. http://dx.doi.org/10.24293/ijcpml.v14i3.927.
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Lactic acid is an intermediate product of carbohydrate metabolism. Increment of plasma lactic acid level usually correlated withaerobic metabolism defect which caused by hypoperfusion or hypoxia, that can be happened in DM (Diabetes Mellitus) patients. DiabetesMellitus is a risk factor of lactic acidosis. Determination of glycated Hb (HbA1c) is a parameter to monitor the blood glucose. The aimof this study is to compare the mean lactic acid level between uncontrolled and controlled DM) patients and their correlation betweenlactic acid and HbA1c level. The research carried out by cross sectional study which was done at the Clinical Pathology Laboratory ofSardjito Hospital between September–October 2007. Inclusion criteria of samples were diabetic patients who had HbA1c examination.Statistical analysis was done by independent t test and Pearson correlation test. Twenty one patients were included in this research.They were divided into two (2) groups, group I are those who had HbA1c ≤ 7%, they consist of 10 patients, group II are patients whohad HbA1c ≥ 7.1%, they consist 11 patients. The mean of lactic acid of group I was 1.85 mmol/L and group II was 1.74 mmol/L (p = 0.574). There wasn’t any significant correlation between HbA1c level and lactic acid. (r = -0.179, p = 0.437). The mean of lacticacid level in uncontrolled DM was lower than the controlled one but not significant, and there was no significant correlation betweenHbA1c level and lactic acid. It is suggested to continue this study but with larger sample to know the correlation between lactic acid andHbA1c in DM patients who had metformin therapy.
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Qiao, Wanjin, Fulu Liu, Xing Wan, Yu Qiao, Ran Li, Zhenzhou Wu, Per Erik Joakim Saris, Haijin Xu i Mingqiang Qiao. "Genomic Features and Construction of Streamlined Genome Chassis of Nisin Z Producer Lactococcus lactis N8". Microorganisms 10, nr 1 (27.12.2021): 47. http://dx.doi.org/10.3390/microorganisms10010047.
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Lactococcus lactis is a commonly used fermenting bacteria in cheese, beverages and meat products. Due to the lack of simplified chassis strains, it has not been widely used in the fields of synthetic biology. Thus, the construction of lactic acid bacteria chassis strains becomes more and more important. In this study, we performed whole genome sequencing, annotation and analysis of L. lactis N8. Based on the genome analysis, we found that L. lactis N8 contains two large plasmids, and the function prediction of the plasmids shows that some regions are related to carbohydrate transport/metabolism, multi-stress resistance and amino acid uptake. L. lactis N8 contains a total of seven prophage-related fragments and twelve genomic islands. A gene cluster encoding a hybrid NRPS–PKS system that was found in L. lactis N8 reveals that the strain has the potential to synthesize novel secondary metabolites. Furthermore, we have constructed a simplified genome chassis of L. lactis N8 and achieved the largest amount of deletion of L. lactis so far. Taken together, the present study offers further insights into the function and potential role of L. lactis N8 as a model strain of lactic acid bacteria and lays the foundation for its application in the field of synthetic biology.
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Cai, Peirong, Nannan Feng, Wanglong Zheng, Hao Zheng, Hui Zou, Yan Yuan, Xuezhong Liu, Zongping Liu, Jianhong Gu i Jianchun Bian. "Treatment with, Resveratrol, a SIRT1 Activator, Prevents Zearalenone-Induced Lactic Acid Metabolism Disorder in Rat Sertoli Cells". Molecules 24, nr 13 (5.07.2019): 2474. http://dx.doi.org/10.3390/molecules24132474.
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Zearalenone (ZEA) interferes with the function of the male reproductive system, but its molecular mechanism has yet to be completely elucidated. Sertoli cells (SCs) are important in the male reproductive system. Silencing information regulator 1 (SIRT1) is a cell metabolism sensor and resveratrol (RSV) is an activator of SIRT1. In this study we investigated whether SIRT1 is involved in the regulation of ZEA-induced lactate metabolism disorder in SCs. The results showed that the cytotoxicity of ZEA toward SCs increased with increasing ZEA concentration. Moreover, ZEA induced a decrease in the production of lactic acid and pyruvate of SCs and inhibited the expression of glycolytic genes and lactic acid production-related proteins. ZEA also led to a decreased expression of SIRT1 in energy receptors and decreased ATP levels in SCs. However, the ZEA-induced cytotoxicity and decline in lactic acid production in SCs were alleviated by the use of RSV, which is an activator of SIRT1. In summary, ZEA decreased lactic acid production in SCs, while the treatment with an SIRT1 activator, RSV, restored the inhibition of lactic acid production in SCs and reduced cytotoxicity of ZEA toward SCs.
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Laptook, Abbot R., Janet Peterson i A. Michael Porter. "Effects of Lactic Acid Infusions and pH on Cerebral Blood Flow and Metabolism". Journal of Cerebral Blood Flow & Metabolism 8, nr 2 (kwiecień 1988): 193–200. http://dx.doi.org/10.1038/jcbfm.1988.49.
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To determine the effects of lactic acidemia versus lactate on CBF, we infused lactic acid, either buffered with NaOH (L + NaOH) or with added NaCl (L + NaCl), to attain similar osmolalities in 18 piglets. CBF (microsphere technique), pH, blood gases, plasma osmolality, and cerebral arteriovenous differences of O2 content and lactic acid concentrations were measured prior to, at 30 min of a lactic acid infusion, and 15 and 90 min after completion of the infusion. Control arterial pH was comparable between groups (7.50 ± 0.02 vs. 7.49 ± 0.02, X̄ ± SE); during and following L + NaCl and L + NaOH, values were (p < 0.05) 7.09 ± 0.03, 7.35 ± 0.02, and 7.46 ± 0.02 vs. 7.58 ± 0.03,7.61 ± 0.01, and 7.57 ± 0.03, respectively. PaCO2 remained unchanged and osmolality rose by 15% in both groups during infusions and persisted throughout the study period. For L + NaCl piglets, CBF (ml/min · 100 g) rose from 136 ± 15 to 198 ±26 (p < 0.05) at 30 min of infusion and remained elevated at 201 ± 25 and 207 ± 28 at 15 and 90 min following the infusion, respectively. Similarly, for L + NaOH piglets, CBF rose from 130 ± 25 to 196 ±31 (p < 0.05) with the infusion and was 174 ± 17 and 166 ± 21 at 15 and 90 min afterward, respectively. Although lactic acid infusion increases CBF, the associated metabolic acidemia is not responsible for changes in CBF.
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THYAGARAJA, NAGAPPA, i AKIYOSHI HOSONO. "Antimutagenicity of Lactic Acid Bacteria from “Idly” Against Food-Related Mutagens". Journal of Food Protection 56, nr 12 (1.12.1993): 1061–66. http://dx.doi.org/10.4315/0362-028x-56.12.1061.
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Lactic acid bacteria from “Idly”, a traditional cereal pulse product of southern India, were evaluated for antimutagenic properties. Effect of their presence in Salmonella mutagenicity assay with foodborne mutagens like spice extracts, amino acid pyrolysates, and aflatoxins was examined. Variation of antimutagenic potential at different growth stages of these lactic acid bacteria was examined in time-course studies. The enzyme profile was examined to determine any possible relationship between antimutagenicity and enzymes in these lactic acid bacteria. Most of the lactic acid bacteria tested were found to decrease mutagenicities exerted by these mutagens significantly. Time-course studies showed that antimutagenic ability decreased in stationary phase of growth of lactic acid bacteria. There was no correlation between antimutagenicity and enzyme profile quantifying proteolytic, lipolytic, and other enzymes of carbohydrate metabolism. Lactic acid bacteria from “Idly” were found to be effective in suppressing the mutagenicities of the kinds encountered in foods.
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Luo, J., C. S. Ranadheera, S. King, C. A. Evans i S. K. Baines. "Potential influence of dairy propionibacteria on the growth and acid metabolism of Streptococcus bovis and Megasphaera elsdenii". Beneficial Microbes 8, nr 1 (7.02.2017): 111–19. http://dx.doi.org/10.3920/bm2016.0044.
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Ruminal acidosis is a prevalent disorder among dairy cows and feedlot cattle, which can significantly impair their health and productivity. This study, involving seven different strains of dairy propionibacteria, represents an in vitro investigation of the feasibility of using these organisms as direct-fed microbials to control lactic acid acumulation in the rumen. Interactions between the propionibacteria, Streptococcus bovis and Megasphaera elsdenii were evaluated in terms of effects on lactic, acetic and propionic acid metabolism, following co-incubation. Spot resistance tests showed slight but varying degrees of growth inhibition by S. bovis among the propionibacteria, while no inhibition was observed between M. elsdenii and the different strains of dairy propionibacteria. In the co-culture experiments comprising S. bovis in nutrient broth, significant differences in pH and the levels of production of lactic, acetic and propionic acid, were observed between treatments following inoculation with various propionibacteria and/or M. elsdenii. In general, lactic acid concentrations at the end of the incubation were significantly lower in the cultures containing propionibacteria compared with cultures comprising either S. bovis only or S. bovis + M. elsdenii, although efficacy of lactate metabolism varied between species and strains. Moreover,the accumulation of acetic and propionic acid in the combined cultures, but not in the solo S. bovis culture, indicated that these compounds were produced as a result of the metabolism of lactic acid by the propionibacteria and M. elsdenii.
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Greter, J., i C. E. Jacobson. "Urinary organic acids: isolation and quantification for routine metabolic screening." Clinical Chemistry 33, nr 4 (1.04.1987): 473–80. http://dx.doi.org/10.1093/clinchem/33.4.473.
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Abstract A method for isolating organic acids from acidified urine on an equivolume mixture of Porapak Q and Porapak T is described, and results are compared with extraction with ethyl acetate and ion exchange on DEAE-Sephadex. Average recoveries of 14C-labeled oxalic acid, lactic acid, succinic acid, alpha-ketoglutaric acid, citric acid, and cinnamic acid were equal to or better than those obtained with the solvent-extraction method. The ion-exchange method gave higher recoveries for oxalic acid, lactic acid, and citric acid. The quantification of separated acids from reconstructed mass spectrometric ion traces is compared with quantification from the simultaneously recorded flame ionization detector response signals. A good correlation was obtained. With the present routine metabolic screening method we have detected several patients with inborn errors of metabolism.
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Guth, H.-J., M. Wiersbitzky, M. Ziesche, H.-J. Rose i G. Kraatz. "Which Amino-Acids do Serum and Hemofiltrate of Critically Ill Patients with Acute Renal Failure Contain?" International Journal of Artificial Organs 20, nr 6 (czerwiec 1997): 309–15. http://dx.doi.org/10.1177/039139889702000603.
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The removal of amino acids during continuous renal replacement therapies induces clinical problems. Previous studies on animals have shown nephroprotective (glycine, alanine) or negative effects (lysine) on renal function in occurrence of acute renal failure. Disturbed metabolism in acute renal failure needs adequate parenteral nutrition. On the other hand, experience with continuous renal replacement therapies of metabolic crises in inborn errors of metabolism indicate a good control of disturbed amino acid metabolism. The aim of our study was to find amino acids, that might play an important role in the pathogenesis, prognosis and detection of acute renal failure and severe illness, so far only estimated by lactic acid. Thirty-three probes (serum and hemofiltrate) were taken from patients, suffering with acute renal failure caused by septic shock, severe pancreatitis and hepatorenal syndrome, one hour after the beginning of extracorporal circulation, the conditions of treatment were standardized. The material was deproteinized and studied by the amino acid analyzer LBK 4251 Apha Plus (Pharmacia, Stockholm, Sweden), while the lactic acid concentration was determined in a standard laboratory. Proline, glycine, alanine, methionine and histidine showed a close relationship to the lactic acid levels, but these amino acids were an essential part of parenteral nutrition. A statistical relationship was also established in (amino acids with amide groups) asparagine, glutamine, citrulline, cystathionine and phosphoethanolamine. The mean values of most of the amino acids were higher than normal, but standard deviations were increased. The presence of these amino acids in hemofiltrate and the good sieving coefficients could mean that the better prognosis of critically ill patients in continuous renal replacement therapies may also be due to continuous control of amino acid levels (especially with amide groups).
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Kleerebezem, Michiel, Herwig Bachmann, Eunice van Pelt-KleinJan, Sieze Douwenga, Eddy J. Smid, Bas Teusink i Oscar van Mastrigt. "Lifestyle, metabolism and environmental adaptation in Lactococcus lactis". FEMS Microbiology Reviews 44, nr 6 (29.09.2020): 804–20. http://dx.doi.org/10.1093/femsre/fuaa033.
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ABSTRACT Lactococcus lactis serves as a paradigm organism for the lactic acid bacteria (LAB). Extensive research into the molecular biology, metabolism and physiology of several model strains of this species has been fundamental for our understanding of the LAB. Genomic studies have provided new insights into the species L. lactis, including the resolution of the genetic basis of its subspecies division, as well as the control mechanisms involved in the fine-tuning of growth rate and energy metabolism. In addition, it has enabled novel approaches to study lactococcal lifestyle adaptations to the dairy application environment, including its adjustment to near-zero growth rates that are particularly relevant in the context of cheese ripening. This review highlights various insights in these areas and exemplifies the strength of combining experimental evolution with functional genomics and bacterial physiology research to expand our fundamental understanding of the L. lactis lifestyle under different environmental conditions.
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KISHINO, Shigenobu, i Jun OGAWA. "Novel Fatty Acid Metabolism of Lactic Acid Bacteria:Application to Functional Fatty Acid Production and Gut Lipid Metabolism Control". KAGAKU TO SEIBUTSU 51, nr 11 (2013): 738–44. http://dx.doi.org/10.1271/kagakutoseibutsu.51.738.
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Alber, Jana, i Michael Föller. "Lactic acid induces fibroblast growth factor 23 (FGF23) production in UMR106 osteoblast-like cells". Molecular and Cellular Biochemistry 477, nr 2 (3.11.2021): 363–70. http://dx.doi.org/10.1007/s11010-021-04287-y.
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AbstractEndocrine and paracrine fibroblast growth factor 23 (FGF23) is a protein predominantly produced by bone cells with strong impact on phosphate and vitamin D metabolism by targeting the kidney. Plasma FGF23 concentration early rises in kidney and cardiovascular diseases correlating with progression and outcome. Lactic acid is generated in anaerobic glycolysis. Lactic acidosis is the consequence of various physiological and pathological conditions and may be fatal. Since FGF23 production is stimulated by inflammation and lactic acid induces pro-inflammatory signaling, we investigated whether and how lactic acid influences FGF23. Experiments were performed in UMR106 osteoblast-like cells, Fgf23 mRNA levels estimated from quantitative real-time polymerase chain reaction, and FGF23 protein determined by enzyme-linked immunosorbent assay. Lactic acid dose-dependently induced Fgf23 gene expression and up-regulated FGF23 synthesis. Also, Na+-lactate as well as formic acid and acetic acid up-regulated Fgf23. The lactic acid effect was significantly attenuated by nuclear factor kappa-light-chain enhancer of activated B-cells (NFκB) inhibitors wogonin and withaferin A. Lactic acid induces FGF23 production, an effect at least in part mediated by NFκB. Lactic acidosis may, therefore, be paralleled by a surge in plasma FGF23.
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Ciosek, Aneta, Katarzyna Fulara, Olga Hrabia, Paweł Satora i Aleksander Poreda. "Chemical Composition of Sour Beer Resulting from Supplementation the Fermentation Medium with Magnesium and Zinc Ions". Biomolecules 10, nr 12 (25.11.2020): 1599. http://dx.doi.org/10.3390/biom10121599.
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The bioavailability of minerals, such as zinc and magnesium, has a significant impact on the fermentation process. These metal ions are known to influence the growth and metabolic activity of yeast, but there are few reports on their effects on lactic acid bacteria (LAB) metabolism during sour brewing. This study aimed to evaluate the influence of magnesium and zinc ions on the metabolism of Lactobacillus brevis WLP672 during the fermentation of brewers’ wort. We carried out lactic acid fermentations using wort with different mineral compositions: without supplementation; supplemented with magnesium at 60 mg/L and 120 mg/L; and supplemented with zinc at 0.4 mg/L and 2 mg/L. The concentration of organic acids, pH of the wort and carbohydrate use was determined during fermentation, while aroma compounds, real extract and ethanol were measured after the mixed fermentation. The addition of magnesium ions resulted in the pH of the fermenting wort decreasing more quickly, an increase in the level of L-lactic acid (after 48 h of fermentation) and increased concentrations of some volatile compounds. While zinc supplementation had a negative impact on the L. brevis strain, resulting in a decrease in the L-lactic acid content and a higher pH in the beer. We conclude that zinc supplementation is not recommended in sour beer production using L. brevis WLP672.
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HUTKINS, R. W., i H. A. MORRIS. "Carbohydrate Metabolism by Streptococcus thermophilus: A Review". Journal of Food Protection 50, nr 10 (1.10.1987): 876–84. http://dx.doi.org/10.4315/0362-028x-50.10.876.
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Despite the widespread use of Streptococcus thermophilus as a starter culture in the manufacture of many fermented dairy products, only recently has an understanding of the basic processes regarding carbohydrate metabolism been developed. Although S. thermophilus is related to other lactic streptococci by virtue of their common use in dairy fermentations, available information indicates that S. thermophilus is serologically, genetically, and physiologically distinct from the Group N, mesophilic streptococci. Carbohydrate metabolism, in particular, occurs by different processes in S. thermophilus than in the Group N streptococci (Streptococcus lactis and Streptococcus cremoris). The latter organisms utilize lactose by a specific phosphoenolpyruvate-dependent phosphotransferase system in which the lactose hydrolysis products, glucose and galactyose-6-phosphate, are concurrently metabolized to lactic acid. In contrast, S. thermophilus lacks phosphotransferase activity and instead possesses a lactose permease. After hydrolysis by β-galactosidase, only glucose is further metabolized and galactose is released into the extracellular medium. Most strains are unable to ferment galactose and are phenotypically galactose-negative. The rapid growth rates of S. thermophilus on lactose and slow growth rates on glucose and galactose are likely due to the differences between the lactose and monosaccharide transport activities. Galactose transport by S. thermophilus requires an exogenous energy source and is mediated by a galactose permease. Galactose is further metabolized in galactose-positive cells by the enzymes of the Leloir pathway, specifically, galactokinase, galactose-1-phosphate uridyl transferase, and uridine-5-diphospho-glucose-4-epimerase. The latter two enzymes are eonstituitively expressed; however, in galactose-positive cells galactokinase and the galactose permease are induced by galactose in the absence of lactose. The phenotypic differences between galactose-positive and galactose-negative S. thermophilus are, in part, due to differences in the galactokinase and galactose permease activities. Galactose released into the medium by lactose-grown, galactose-positive cells can be subsequently metabolized, homofermentatively, to lactic acid. However, the important practical implications of released galactose has produced the need for isolation and development of S. thermophilus strains which ferment the lactose components, glucose and galactose, completely and simultaneously.
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Rowe, J. B., Z. Ding, I. R. Godwin, Y. Xu, F. M. Ball i S. Atkinson. "No lactic acid absorbed from the caecum and rumen of sheep". Australian Journal of Agricultural Research 49, nr 2 (1998): 293. http://dx.doi.org/10.1071/a97077.
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A comparative study of the absorption of lactic acid, volatile fatty acids (VFA), glucose, and ammonia from caecal and rumen pouches was undertaken in anaesthetised sheep. Test solutions varying in pH, osmolarity, lactic acid concentration, and with fixed concentrations of VFA, ammonia, and glucose (100, 7, and 4 mmol/L, respectively) were introduced into the clean, surgically sealed pouches. Studies were undertaken in 9 sheep, each with 2 pouches in the caecum and 1 in the rumen. Samples were taken at 10-min intervals for 50 min to determine rate of absorption. Neither L-lactic acid nor D-lactic acid was absorbed from the caecal or rumen pouch and there was a slight increase in both isomers of lactic acid (0·39%/min of L-lactic acid and 0·24%/min of D-lactic acid averaged for the caecum and rumen values) which was presumably due to conversion of propionic acid and tissue metabolism during the experiment. The rate of increase per unit area in the caecum (0·06 µmol/cm2·min) was much greater than that in the rumen (0·015 µmol/cm2·min) based on the average of L- and D-lactic acid. The absorption rates of acetic, propionic, and butyric acids from the caecum (0·49, 0·17, and 0·08 µmol/cm2 ·min, respectively) and the rumen (0·48, 0·16, and 0·08 µmol/cm2· min, respectively), based on absorptive surface area of the pouches, were very similar. Glucose was apparently absorbed from rumen pouches (0·18 µmol/cm2 ·min), but not from caecal pouches (-0·01 µmol/cm2·min). The mean absorption rate of ammonia from caecal pouches (0·60 µg N/cm2·min) was 2·5 times greater than that from rumen pouches (0·24 µg N/cm2·min) (P < 0·0001). The mean absorption rate of ammonia for the caecal and rumen pouches was about 2·6 times higher at pH 6·5 (0·99%/min) than that at pH 4·5 (0·38%/min) (P < 0·0001) at the same osmolarity and lactic acid concentration. A decrease in pH, osmotic pressure, or the concentration of lactic acid resulted in corresponding increases in the absorption of VFA.
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Lemieux, Guy, Eduardo Junco, Raphael Perez, Elizabeth Allignet, Christiane Lemieux, Manuel Rengel Aranda i Fernando Valderrabano Quintana. "Renal metabolism during four types of lactic acidosis in the dog including anoxia". Canadian Journal of Physiology and Pharmacology 64, nr 2 (1.02.1986): 169–75. http://dx.doi.org/10.1139/y86-025.
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The present study was undertaken to evaluate the metabolic response of the kidney to lactic acidosis. Four types of lactic acidosis were induced in the dog: infusion of lactic acid, infusion of lactic acid with phenformin, administration of phenformin alone, and hypoxia by breathing 95% nitrogen. In all groups of animals, the same degree of acidosis was observed with plasma bicarbonate ranging from 12.8 to 14.9 mM. Plasma lactate concentration ranged from 3.0 to 8.1 μmol/mL. Renal ammoniagenesis failed to be influenced by lactic acidosis. As a matter of fact, it fell during anoxia. The extraction of glutamine by the kidney rose except during anoxia where it fell. The renal production of alanine rose during the infusion of lactic acid with and without phenformin. This coincided with the extraction of glutamine. The renal extraction of lactate rose in all forms of acidosis as well as the production of pyruvate. In the renal cortical tissue, the concentration of malate, pyruvate, and lactate rose. Alanine also rose except during anoxia. An important fall in cytosolic redox potential (NAD+/NADH lactate dehydrogenase) was observed, as well as a fall in mitochondrial redox (NAD+/NADH beta-hydroxybutyrate dehydrogenase). Lactate also accumulated in the liver and in the muscle. We propose that the kidney is unable to respond to lactic acidosis in terms of ammonia production and that this phenomenon is explained by transamination of pyruvate and glutamate into alanine and also by the observed fall in cytosolic redox potential. It is likely that renal gluconeogenesis is also inhibited and this is reflected by the rise in the concentration of malate in the kidney. Gross anoxia provokes the most severe form of lactic acidosis and the more important biochemical changes including a decrease in the uptake of glutamine and in ammonia production by the kidney.
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Bodzen, Aurore, Audrey Jossier, Sébastien Dupont, Pierre-Yves Mousset, Laurent Beney, Sophie Lafay i Patrick Gervais. "Increased Survival of Lactococcus lactis Strains Subjected to Freeze-Drying after Cultivation in an Acid Medium: Involvement of Membrane Fluidity". Food Technology and Biotechnology 59, nr 4 (2021): 443–53. http://dx.doi.org/10.17113/ftb.59.04.21.7076.
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Research background. Freeze-drying is the most widely used dehydration process in the food industry for the stabilization of bacteria. Studies have shown the effectiveness of an acid prestress in increasing the resistance of lactic acid bacteria to freeze-drying. Adaptation of bacteria to an acid stress is based on maintaining the properties of the plasma membrane. Indeed, the fatty acid composition of the membrane of lactic acid bacteria is often changed after an acid prestress. However, few studies have measured membrane fluidity after an acid stress during lactic acid bacterial strain cultivation. Experimental approach. In order to use two pH profiles, the strains Lactococcus lactis NCDO 712 and NZ9000 were cultivated in two media, without any pH control. The two pH profiles obtained were representative of the initial medium composition, medium buffering properties and strain metabolism. Absorbance at 600 nm and pH were measured during bacterial cultivation. Then, the two strains were freeze-dried and their survival rates determined. Membrane fluidity was evaluated by fluorescence anisotropy measurements using a spectrofluorometer. Results and conclusions. Cultivation under more acidic conditions significantly increased the survival during freeze-drying (p<0.05, ANOVA) of both strains. Moreover, in both strains of L. lactis, a more acidic condition during cultivation significantly increased membrane fluidity (p<0.05, ANOVA). Our results revealed that cultivation under such conditions, fluidifies the membrane and allows a better survival during freeze-drying of the two L. lactis strains. A more fluid membrane can facilitate membrane deformation and lateral reorganization of membrane components, critical for the maintenance of cellular integrity during dehydration and rehydration. Novelty and scientific contribution. A better understanding of the involvement of membrane properties, especially of membrane fluidity, in bacterial resistance to dehydration is provided in this study.
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Ferrarelli, Leslie K. "From lactate to antidepressant". Science Signaling 14, nr 686 (8.06.2021): eabj8007. http://dx.doi.org/10.1126/scisignal.abj8007.
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Filannino, Pasquale, Raffaella Di Cagno, Rocco Addante, Erica Pontonio i Marco Gobbetti. "Metabolism of Fructophilic Lactic Acid Bacteria Isolated from the Apis mellifera L. Bee Gut: Phenolic Acids as External Electron Acceptors". Applied and Environmental Microbiology 82, nr 23 (16.09.2016): 6899–911. http://dx.doi.org/10.1128/aem.02194-16.
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ABSTRACTFructophilic lactic acid bacteria (FLAB) are strongly associated with the gastrointestinal tracts (GITs) ofApis melliferaL. worker bees due to the consumption of fructose as a major carbohydrate. Seventy-seven presumptive lactic acid bacteria (LAB) were isolated from GITs of healthyA. melliferaL. adults, which were collected from 5 different geographical locations of the Apulia region of Italy. Almost all of the isolates showed fructophilic tendencies: these isolates were identified asLactobacillus kunkeei(69%) orFructobacillus fructosus(31%). A high-throughput phenotypic microarray targeting 190 carbon sources was used to determine that 83 compounds were differentially consumed. Phenotyping grouped the strains into two clusters, reflecting growth performance. The utilization of phenolic acids, such asp-coumaric, caffeic, syringic, or gallic acids, as electron acceptors was investigated in fructose-based medium. Almost all FLAB strains showed tolerance to high phenolic acid concentrations.p-Coumaric acid and caffeic acid were consumed by all FLAB strains through reductases or decarboxylases. Syringic and gallic acids were partially metabolized. The data collected suggest that FLAB require external electron acceptors to regenerate NADH. The use of phenolic acids as external electron acceptors by the 4 FLAB showing the highest phenolic acid reductase activity was investigated in glucose-based medium supplemented withp-coumaric acid. Metabolic responses observed through a phenotypic microarray suggested that FLAB may usep-coumaric acid as an external electron acceptor, enhancing glucose dissimilation but less efficiently than other external acceptors such as fructose or pyruvic acid.IMPORTANCEFructophilic lactic acid bacteria (FLAB) remain to be fully explored. This study intends to link unique biochemical features of FLAB with their habitat. The quite unique FLAB phenome within the group lactic acid bacteria (LAB) may have practical relevance in food fermentations. The FLAB phenome may have implications for the levels of hexose metabolism products in fermented foods, as well as food probiotication. Due to the harsh conditions of honeybees' GITs, these bacteria had to develop specific physiological and biochemical characteristics, such as tolerance to phenolic acids. The screening of FLAB strains based on metabolic pathways involving phenolic acids may allow the selection of starter cultures with both technological and functional beneficial attributes. Bioconversion of phenolic compounds may contribute to the aroma attributes and biofunctionality of fermented foods. Thus, the selection of FLAB strains as starter cultures with specific enzymatic activities involving phenolic acids may have a promising role in food fermentations.
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Upadhyay, R. C., i M. L. Madan. "Studies on blood acid-base status and muscle metabolism in working bullocks". Animal Science 40, nr 1 (luty 1985): 11–16. http://dx.doi.org/10.1017/s0003356100031792.
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ABSTRACTHaryana and crossbred (Holstein × local Haryana) bullocks were subjected to work under heavy loads in summer. During the work, bullocks exhibited distress symptoms. After work, rectal temperature, respiration rate, heart rate and minute volume increased significantly, the average pO2 content increased, muscle lactic acid increased and creatine phosphate level declined. From the results it was evident that oxygen availability in blood improved during work. Despite the enhanced oxygenation of blood, there was accumulation of lactic acid in muscle. This indicated a certain degree of tissue hypoxia, which probably brought about fatigue earlier.
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Oliveira, Juliana Silva de, Augusto César de Queiroz, Hilário Cuquetto Mantovani, Marcelo Rodrigues de Melo, Edenio Detmann, Edson Mauro Santos i Geraldo Fábio Viana Bayão. "Effect of propionic and lactic acids on in vitro ruminal bacteria growth". Revista Brasileira de Zootecnia 40, nr 5 (maj 2011): 1121–27. http://dx.doi.org/10.1590/s1516-35982011000500025.
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The objective of this work was to evaluate the effect of the levels of lactic and propionic acids on in vitro fermentation of ruminal microorganisms. In experiment 1, the levels, in a total of 12 were the following: addition of 0 (control 1), 50, 100, 150, 200 and 250 mM of lactic acid and 0 (control 2), 50, 100, 150, 200 and 250 mM of propionic acid, respectively, in incubation flasks, which contained ruminal inoculum, glucose and synthetic culture medium, with two repetitions for each combination. In experiment 2, the combinations, in a total of 4, were the following: presence of 12 and 24 mM of propionic acid and 0 mg of glucose, respectively; presence of 12 and 24 mM of propionic acid and 40 mg of glucose, respectively, to the incubation flasks which contained ruminal inoculum, with or without glucose and in synthetic culture medium with two repetitions each. There was no effect on the specific growth velocity of ruminal microorganisms in the presence of lactic acid or propionic acid. However, when there were greater concentrations of these acids in the media, there was a longer lag phase in the microorganism phase. Acid propionic at the concentration of 24 mM inhibited the production of acid acetic and butyric acid in a media with glucose. Despite of not being used as a source of energy by the ruminal microorganisms, propionic acid affects their metabolism. Lactic and propionic acids inhibit growth of some ruminal microorganisms at elevated concentrations.
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Wang, Joy X., Stephen Y. C. Choi, Xiaojia Niu, Ning Kang, Hui Xue, James Killam i Yuzhuo Wang. "Lactic Acid and an Acidic Tumor Microenvironment suppress Anticancer Immunity". International Journal of Molecular Sciences 21, nr 21 (7.11.2020): 8363. http://dx.doi.org/10.3390/ijms21218363.
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Immune evasion and altered metabolism, where glucose utilization is diverted to increased lactic acid production, are two fundamental hallmarks of cancer. Although lactic acid has long been considered a waste product of this alteration, it is now well accepted that increased lactic acid production and the resultant acidification of the tumor microenvironment (TME) promotes multiple critical oncogenic processes including angiogenesis, tissue invasion/metastasis, and drug resistance. We and others have hypothesized that excess lactic acid in the TME is responsible for suppressing anticancer immunity. Recent studies support this hypothesis and provide mechanistic evidence explaining how lactic acid and the acidic TME impede immune cell functions. In this review, we consider lactic acid’s role as a critical immunoregulatory molecule involved in suppressing immune effector cell proliferation and inducing immune cell de-differentiation. This results in the inhibition of antitumor immune responses and the activation of potent, negative regulators of innate and adaptive immune cells. We also consider the role of an acidic TME in suppressing anticancer immunity. Finally, we provide insights to help translate this new knowledge into impactful anticancer immune therapies.
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Vido, Karin, Dominique le Bars, Michel-Yves Mistou, Patricia Anglade, Alexandra Gruss i Philippe Gaudu. "Proteome Analyses of Heme-Dependent Respiration in Lactococcus lactis: Involvement of the Proteolytic System". Journal of Bacteriology 186, nr 6 (15.03.2004): 1648–57. http://dx.doi.org/10.1128/jb.186.6.1648-1657.2004.
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ABSTRACT Sugar fermentation was long considered the sole means of energy metabolism available to lactic acid bacteria. We recently showed that metabolism of Lactococcus lactis shifts progressively from fermentation to respiration during growth when oxygen and heme are available. To provide insights into this phenomenon, we compared the proteomic profiles of L. lactis under fermentative and respiratory growth conditions in rich medium. We identified 21 proteins whose levels differed significantly between these conditions. Two major groups of proteins were distinguished, one involved in carbon metabolism and the second in nitrogen metabolism. Unexpectedly, enzymes of the proteolytic system (PepO1 and PepC) which are repressed in rich medium in fermentation growth were induced under respiratory conditions despite the availability of free amino acids. A triple mutant (dtpT dtpP oppA) deficient in oligopeptide transport displayed normal respiration, showing that increased proteolytic activity is not an absolute requirement for respiratory metabolism. Transcriptional analysis confirmed that pepO1 is induced under respiration-permissive conditions. This induction was independent of CodY, the major regulator of proteolytic functions in L. lactis. We also observed that pepO1 induction is redox sensitive. In a codY mutant, pepO1 expression was increased twofold in aeration and eightfold in respiration-permissive conditions compared to static conditions. These observations suggest that new regulators activate proteolysis in L. lactis, which help to maintain the energetic needs of L. lactis during respiration.