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Inorganic Acids (inorganic + acid)
Selected AbstractsPhysiological and molecular analysis of the stress response of Saccharomyces cerevisiae imposed by strong inorganic acid with implication to industrial fermentationsJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2010H.F. De Melo Abstract Aims:, This work aimed to identify the molecular mechanism that allows yeast cells to survive at low pH environments such as those of bioethanol fermentation. Methods and Results:, The industrial strain JP1 cells grown at pH 2 was evaluated by microarray analysis showing that most of the genes induced at low pH were part of the general stress response (GSR). Further, an acid-tolerant yeast mutant was isolated by adaptive selection that was prone to grow at low pH in inorganic but weak organic acid. It showed higher viability under acid-temperature synergistic treatment. However, it was deficient in some physiological aspects that are associated with defects in protein kinase A (PKA) pathway. Microarray analysis showed the induction of genes involved in inhibition of RNA and protein synthesis. Conclusions:, The results point out that low pH activates GSR, mainly heat shock response, that is important for long-term cell survival and suggest that a fine regulatory PKA-dependent mechanism that might affect cell cycle in order to acquire tolerance to acid environment. Significance and Impact of the Study:, These findings might guide the construction of a high-fermentative stress-tolerant industrial yeast strain that can be used in complex industrial fermentation processes. [source] ISOLATION and CHARACTERIZATION of MANGO PEEL PECTINSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2000D.V. SUDHAKAR An efficient method for manufacture of pectin from Totapuri mango peels was standardized by studying various factors that govern the recovery and quality of pectin. Among the different organic and inorganic acids, 0.05 N HCl was found to be the best for recovery of pectin from mango peels. Optimum yield of pectin was obtained by taking two extractions each for one-hour duration employing a peel: extractant ratio of 1:2 and by alcohol precipitation method. Dried mango peels could be stored for six months at ambient conditions (14.5,33.9C) without any significant effect on the recovery of pectin. Pectin extract, an intermediate product in the manufacture of pectin, could be stored for one month either at low temperature (6C±2) or at ambient conditions (24.5,33.0C) by the addition of 700 ppm SO2 with minimum loss in the recovery of pectin. Using the optimum extracting conditions about 20.8% (DWB) of purified pectin was obtained from mango peels. the powdered pectin could be stored for over 6 months without any deterioration in quality when packed in airtight containers at ambient conditions. [source] Supramolecular motifs in the first structures of organic carboxylate salts of 1-(diaminomethylene)thiourea (HATU)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009gorzata Ho The structures of the first two organic carboxylate salts of 1-(diaminomethylene)thiourea (HATU), namely 1-(diaminomethylene)thiouron-1-ium formate, C2H7N4S+·HCOO,, (I), and bis[1-(diaminomethylene)thiouron-1-ium] oxalate dihydrate, 2C2H7N4S+·C2O42,·2H2O, (II), in which the oxalate lies on a symmetry centre, possess different extended hydrogen-bonding networks with different graph-set motifs. The R22(8) motif present in (I) does not appear in (II), but an R21(6) motif is present in both (I) and (II). Compound (I) has a three-dimensional hydrogen-bonding network, whereas (II) has a layered structure with layers joined by hydrogen-bonding motifs that form R42(8) patterns. This work extends the known supramolecular structural data for HATU to include these organic carboxylates in addition to the previously characterized salts with inorganic acids. [source] Expanding Sapphyrin: Towards Selective Phosphate BindingCHEMISTRY - A EUROPEAN JOURNAL, Issue 29 2008Evgeny Abstract The anion-templated syntheses and binding properties of novel macrocyclic oligopyrrole receptors in which pyrrole rings are linked through amide or imine bonds are described. The efficient synthesis was accomplished by anion-templated [1+1] Schiff-base condensation and acylation macrocyclization reactions. Free receptors and their host,guest complexes with hydrochloric acid, acetic acid, tetrabutylammonium chloride, and hydrogen sulfate were analyzed by single-crystal X-ray diffraction analysis. Stability constants with different tetrabutylammonium salts of inorganic acids were determined by standard 1H,NMR and UV/Vis titration techniques in [D6]DMSO/0.5,% water solution. According to the titration data, receptors containing three pyrrole rings (10 and 12) exhibit high affinity (log,Ka=5,7) for bifluoride, acetate, and dihydrogen phosphate, and interact weakly with chloride and hydrogen sulfate. The amido-bipyrrole receptors 11 and 13 with four pyrrole rings exhibit 104 - and 102 -fold selectivity for dihydrogen phosphate, respectively, as inferred from competitive titrations in the presence of tetrabutylammonium acetate. [source] | ||||||||||