Search results for "lactic acid"
showing 10 items of 660 documents
Dextransucrase Expression Is Concomitant with that of Replication and Maintenance Functions of the pMN1 Plasmid in
2017
The exopolysaccharide synthesized by Lactobacillus sakei MN1 is a dextran with antiviral and immunomodulatory properties of potential utility in aquaculture. In this work we have investigated the genetic basis of dextran production by this bacterium. Southern blot hybridization experiments demonstrated the plasmidic location of the dsrLS gene, which encodes the dextransucrase involved in dextran synthesis. DNA sequencing of the 11,126 kbp plasmid (pMN1) revealed that it belongs to a family which replicates by the theta mechanism, whose prototype is pUCL287. The plasmid comprises the origin of replication, repA, repB, and dsrLS genes, as well as seven open reading frames of uncharacterized f…
Development of molecular approaches for direct detection and quantification of wine-related microorganisms
2018
En esta tesis doctoral se han desarrollado procedimientos para la detección y cuantificación de levaduras y bacterias acéticas totales y, en concreto, de las especies más importantes en la vinificación como Saccharomyces cerevisiae, Brettanomyces bruxellensis, Zygosaccharomyces bailii, L. plantarum, y O. oeni. Las estrategias que se han utilizado para el desarrollo de nuevos métodos se centran fundamentalmente en la supresión del paso de extracción previa de ADN y de los procedimientos de eliminación de inhibidores de la reacción de PCR presentes en las muestras. Para llevar a cabo este objetivo general, se establecieron los siguientes objetivos específicos; 1, desarrollo de un método de qP…
Sourdough and cereal-based foods: traditional and innovative products
2017
Cereals represent the main crop of the five continents and contribute greatly to the diet of several populations. Cereals often undergo a fermentation before eating. This process is fundamental to confer high sensory quality, as well as to preserve and enhance the nutritional and safety aspects of the resulting products. Fermented cereal based foods are complex microbial ecosystems, mainly represented by lactic acid bacteria and yeasts. Among these products, sourdough is worldwide applied to produce breads. Sourdough technology is also used to improve the final characteristics of fortified and gluten–free breads. This chapter focuses on the use of cereals to produce the most relevant fermen…
Lindane-induced changes in carbohydrate metabolism in Anguilla anguilla
1992
Abstract 1. Anguilla anguilla (L.) was exposed to a sublethal concentration of 0.167 ppm (0.25 of the 96-hr lc 50 ) of lindane for 6, 12, 24, 48, 72 and 96 hr. 2. Changes in glycogen, glucose, pyruvate and lactate contents of liver and muscle after lindane exposure, were studied. 3. Muscle and liver glycogen levels decreased significantly during the exposure time. Muscle glucose values increased but on the other hand we found a decrease in those of liver. 4. Muscle and liver pyruvate content increased as did lactate levels in both tissues. 5. The observed effects of lindane on carbohydrate metabolism in fish are discussed in relation to acute stress syndrome.
Effects of Extracellular Acidosis on Glial Cell Intracellular pH: Evidence for a Glial Spatial H+-Buffering Mechanism?
1994
Acidosis and in particular lactacidosis from anaerobic metabolism are considered of primary significance among the consequences of cerebral ischemia, seizures,, and head injury (Siesjo 1981). A marked decrease in brain tissue pH has been demonstrated in cerebral ischemia - even more so in hyperglycemic subjects - where lactic acid may accumulate to 20–30 mM and higher concentrations (Rehncrona et al. 1980; Katsura et al. 1991). Tissue pH may drop to pH 5.5 (Chopp et al. 1988). In consequence, acidosis has since long been suspected as a mediator of brain damage (Siesjo 1981).
Is there a critical tissue oxygen tension for bioenergetic status and cellular pH regulation in solid tumors?
1996
Bioenergetic and metabolic status have been correlated with tissue oxygenation in murine fibrosarcomas (FSaII) of varying sizes (44-600 mm3). Ratios of beta-nucleoside triphosphates to inorganic phosphate (beta NTP/P) and phosphocreatine to inorganic phosphate (PCr/P(i)) ratios derived from 31P nuclear magnetic resonance spectroscopy (NMR) were positively correlated to median tissue O2 tension (pO2) values using O2-sensitive needle electrodes. pH declined during growth with intracellular acidosis being evident in tumors350 mm3. Whereas lactic acid formation greatly contributed to this decline in small and medium-sized tumors, adenosine triphosphate (ATP) hydrolysis and slowing down of the a…
Intracellular acidosis in murine fibrosarcomas coincides with ATP depletion, hypoxia, and high levels of lactate and total Pi
1994
Bioenergetic and metabolic status of murine FSaII tumours were evaluated using 31P MRS, acid extracts ('global' techniques) and quantitative bioluminescence ('microregional' assay). Data obtained from s.c. tumours of varying sizes (44-600 mm3) have been correlated with the oxygenation status evaluated using O2-sensitive needle electrodes. beta-NTP/Pi and phosphocreatine (PCr)/Pi ratios derived from 31P MRS were positively correlated to the median tissue pO2 values. pH declined during growth with intracellular acidosis being evident in tumours > 350 mm3. Whereas lactic acid formation greatly contributed to this decline in small- and medium-sized tumours, ATP hydrolysis and slowing down of th…
Intestinal ischaemia during cardiac arrest and resuscitation: comparative analysis of extracellular metabolites by microdialysis.
2003
Intestinal ischaemia is a major complication of shock syndromes causing translocation of bacteria and endotoxins and multiple organ failure in intensive care patients. The present study was designed to use microdialysis as a tool to monitor intestinal ischaemia after cardiac arrest and resuscitation in pigs. For this purpose, microdialysis probes were implanted in pig jejunal wall, peritoneum, skeletal muscle and brain, and interstitial fluid was obtained during circulatory arrest (induced by ventricular fibrillation) and after return of spontaneous circulation (ROSC). Cardiac arrest for 4 min caused a prolonged (60 min) reduction of blood flow in jejunal wall, muscle and brain as determine…
Prognostic value of blood lactate in critically ill patients
1984
Hyperlactatemia is frequently observed in critically ill patients. A correlation of blood lactate concentrations and outcome of patients has been proven in circulatory shock, circulatory arrest, acute myocardial infarction, acute hypnotic drug poisoning and severe pancreatitis. However, the prognostic relevance of hyperlactatemia yields from statistical examinations in larger groups of patients. It should not be misused as a reliable prognostic sign in the individual patient, but is of high value in comparing groups of patients. In individual patients, hyperlactatemia is a useful indicator pointing to the severity of illness and to superimposed complications. Blood lactate is of considerabl…
Effects of severe arterial hypocapnia on regional blood flow regulation, tissuePO2 and metabolism in the brain cortex of cats
1981
The effect of a stepwise decrease in PaCO2 from 3.9-1.6 kPa on rCBF, rCMRO2, tissue PO2 and concentrations of glucose, lactate, pyruvate, ATP, ADP, AMP and phosphocreatine in the brain cortex was studied in cats lightly anaesthetized with sodium pentobarbital. 1. Moderate lowering of PaCO2 to 2.5 kPa induced in all animals a homogeneous decrease of rCBF in corresponding areas of the right and left hemisphere. Mean rCBF fell from 129.2 to 103.1 ml X 100 g-1 X min-1, while rCMRO2 remained unchanged (12.7-12.9 ml X 100 g-1 X min-1). The tissue PO2 frequency histograms showed a shift to lower values without indicating the presence of brain tissue hypoxia. 2. Severe arterial hypocapnia (PaCO2 = …