Search results for " biotechnology"
showing 10 items of 3723 documents
Translational fusion to the Pir4 cell wall protein as a general and efficient method for cell surface immobilization or growth medium secretion of re…
2008
Allelic variants of hexose transporter Hxt3p and hexokinases Hxk1p/Hxk2p in strains ofSaccharomyces cerevisiaeand interspecies hybrids
2015
The transport of sugars across the plasma membrane is a critical step in the utilization of glucose and fructose by Saccharomyces cerevisiae during must fermentations. Variations in the molecular structure of hexose transporters and kinases may affect the ability of wine yeast strains to finish sugar fermentation, even under stressful wine conditions. In this context, we sequenced and compared genes encoding the hexose transporter Hxt3p and the kinases Hxk1p/Hxk2p of Saccharomyces strains and interspecies hybrids with different industrial usages and regional backgrounds. The Hxt3p primary structure varied in a small set of amino acids, which characterized robust yeast strains used for the p…
Interrelationships between Growth Yield, ATPase and Adenylate Kinase Activities inZymomonas mobilis
2001
The presence of cytoplasmic and membrane-bound adenylate kinase (EC 2.7,4.3) as well as inorganic pyrophosphatase (EC 3.6.1.1) was detected in Zymomonas mobilis ATCC 29191. An increase in the molar growth yield (Y X/S ) of Z. mobilis under aerobic growth conditions appeared to be in proportion to a reduction of membrane-bound adenylate kinase (mAK) and ATPase activities and to an increase in cytoplasmic adenylate kinase (AK) activity. Significant (1 - P < 0.01) multiple regressions were observed between the values of Y x (dependent variable), ATPase and AK or AK and mAK as independent variables, suggesting that a combined operation of these phosphohydrolases and phosphotransferases would be…
Distribution and mobility of phosphates and sodium ions in cheese by solid-state 31 P and double-quantum filtered 23 Na NMR spectroscopy
2010
The feasibility of solid-state magic angle spinning (MAS) (31)P nuclear magnetic resonance (NMR) spectroscopy and (23)Na NMR spectroscopy to investigate both phosphates and Na(+) ions distribution in semi-hard cheeses in a non-destructive way was studied. Two semi-hard cheeses of known composition were made with two different salt contents. (31)P Single-pulse excitation and cross-polarization MAS experiments allowed, for the first time, the identification and quantification of soluble and insoluble phosphates in the cheeses. The presence of a relatively 'mobile' fraction of colloidal phosphates was evidenced. The detection by (23)Na single-quantum NMR experiments of all the sodium ions in t…
Tryptophan catabolism via kynurenine production in Streptomyces coelicolor: identification of three genes coding for the enzymes of tryptophan to ant…
2011
Most enzymes involved in tryptophan catabolism via kynurenine formation are highly conserved in Prokaryotes and Eukaryotes. In humans, alterations of this pathway have been related to different pathologies mainly involving the central nervous system. In Bacteria, tryptophan and some of its derivates are important antibiotic precursors. Tryptophan degradation via kynurenine formation involves two different pathways: the eukaryotic kynurenine pathway, also recently found in some bacteria, and the tryptophan-to-anthranilate pathway, which is widespread in microorganisms. The latter produces anthranilate using three enzymes also involved in the kynurenine pathway: tryptophan 2,3-dioxygenase (TD…
Sources, Chemistry, and Biological Potential of Ellagitannins and Ellagic Acid Derivatives
2019
Abstract The consumption of polyphenols is considered an important part of a healthy life style and is related to reducing the risk for diseases. Ellagitanins (e.g., vescalagin, punicalagin, and castalagin) and ellagic acid and its derived compounds (e.g., urolithin) have been receiving attention in recent years as bioactive substances. This class of phenolic substances can be found in berries, pomegranates, walnuts, almonds, and other plant material that is consumed as traditional medicine to treat inflammatory diseases. Human gut microbiota are considered to play an important role in the bioactivity of ellagic acid derivative activity due to the production of urolithin and its antiinflamm…
Acid tolerance inLeuconostoc oenos. Isolation and characterization of an acid-resistant mutant
1996
The acid tolerance ofLeuconostoc oenos was examined in cells surviving at pH 2.6, which is lower than the acid limit of growth (about pH 3.0). Acid-adapted cells survived better than non-adapted cells. Tolerance to acid stress was found to be dependent upon the adaptive pH. Acid resistance was increased by an order of magnitude for cultures adapted to a pH of about 2.9. Inhibiting protein synthesis with chloramphenicol prior to acid shock revealed that acid adaptation may involve two separate systems, one of which appears to be independent of protein synthesis. The acid-resistant mutant LoV8413, isolated during a long-term survival screen at pH 2.6, was found to be able to grow in acidic me…
Chemical and physico‐chemical changes during the dry‐cured processing of deer loin
2019
The changes on chemical composition, physico‐chemical parameters, free fatty acids and free amino acids content of dry‐cured deer loin were investigated at day 0, 30 and 60 of dry‐cured process. On the whole, except for pH values (≈5.6) and composition (fat: 4.6–5.2%; protein: ≈73%; ash: ≈17.5%) that did not show differences between the processing days, the other physico‐chemical parameters were affected by curing process. Colour parameters and moisture (from 69 to 38.4%) decreased while the hardness increase from 12.35 to 342 N and lipid oxidation (from 0.2 to 0.52 mg MDA/kg) increased as dry‐cured stage progresses. In similar way, free fatty acid (2250 mg per 100 g of fat at 0 day and 594…
The yeastWickerhamomyces anomalusAS1 secretes a multifunctional exo-β-1,3-glucanase with implications for winemaking
2014
A multifunctional exo-β-1,3-glucanase (WaExg2) was purified from the culture supernatant of the yeast Wickerhamomyces anomalus AS1. The enzyme was identified by mass spectroscopic analysis of tryptic peptide fragments and the encoding gene WaEXG2 was sequenced. The latter codes for a protein of 427 amino acids, beginning with a probable signal peptide (17 aa) for secretion. The mature protein has a molecular mass of 47 456 Da with a calculated pI of 4.84. The somewhat higher mass of the protein in SDS–PAGE might be due to bound carbohydrates. Presumptive disulphide bridges confer a high compactness to the molecule. This explains the apparent smaller molecular mass (35 kDa) of the native enz…