Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.15 (pectinase)
 2,440 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The efficacy of enzyme-assisted ensiling (ENLAC) in the recovery of polyphenols from rosemary and sage was tested. Fresh rosemary and sage were chopped and ensiled in 0.5-L anaerobic jars. Treatments comprised control (no additives), 0.5% glucose and lactic acid bacteria, and 1% cellulase plus 1% hemicellulase plus pectinase. Following storage at room temperature for 45 days (experiment 1) and 26 days (experiment 2), polyphenols were extracted from the silages in ethanol either by direct blending or by cold extraction. The enzyme treatment resulted in silages with the lowest pH values, lowest fiber content, highest water-soluble sugar content, and highest polyphenol recovery; this treatment resulted in increased polyphenol recovery from rosemary and sage, by 100 and 20%, respectively. Comparison between direct blending and cold extraction revealed similar efficiency of polyphenol recovery.
 ...
PMID:Enhancement of polyphenol recovery from rosemary (Rosmarinus officinalis) and sage (Salvia officinalis) by enzyme-assisted ensiling (ENLAC). 1055 93

Pectin methyltransferase (PMT) catalyzing the transfer of the methyl group from S-adenosyl-L-methionine (SAM) to the C-6 carboxyl group of galactosyluronic acid residues in pectin was found in a membrane preparation of etiolated hypocotyls from 6-d-old soybean (Glycine max Merr.). The enzyme was maximally active at pH 6.8 and 35-40 degrees C, and required 0.5% (w/v) Triton X-100. The incorporation of the methyl group was significantly enhanced by addition of a pectin with a low (22%) degree of methyl-esterification (DE) as exogenous acceptor substrate. The apparent Michaelis constants for SAM and the pectin (DE22) were 0.23 mM and 66 microg x ml(-1), respectively. Attachment of the methyl group to the carboxyl group of the pectin via ester linkage was confirmed by analyzing radiolabeled product from incubation of the enzyme with [14C]methyl SAM and the acceptor pectin. Size-exclusion chromatography showed that both enzymatic hydrolysis with a pectin methylesterase and a mild alkali treatment (saponification) led to the release of radioactive methanol from the product. Enzymatic hydrolysis of the product with an endopolygalacturonase degraded it into small pectic fragments with low relative molecular mass, which also supports the idea that the methyl group is incorporated into the pectin. The soybean hypocotyls were fractionated into their cell wall components by successive extraction with water, EDTA, and alkali treatment. Among the resulting polysaccharide fractions, high PMT activity was observed when a de-esterified polysaccharide derived from the EDTA-soluble fraction (the pectic fraction) was added as an alternative acceptor substrate, indicating that the enzyme may be responsible for producing methyl-esterified pectin in vivo.
 ...
PMID:Characterization of pectin methyltransferase from soybean hypocotyls. 1080 50

Water-soluble polysaccharide fractions VO1-VO4 were isolated from the squeezed berries of snowball tree (Viburnum opulus) by successive extraction with water at various temperatures and pH and with aqueous solutions of ammonium oxalate. These fractions were purified by ion-exchange chromatography on DEAE cellulose, and the homogeneity of the purified polysaccharides was determined by gel filtration on Sephacryl S-500. Acidic polysaccharides close to pectins in their sugar composition were found in all the extracts (fractions VO1-1, VO2-1, VO3-2, and VO4-2). Residues of galacturonic acid, galactose, arabinose, and (to a lesser extent) rhamnose are their main constituents. Neutral polysaccharides composed mainly of galactose and mannose residues were additionally found in fractions extracted with acidified water (pH 4.0) and with aqueous ammonium oxalate solutions. Partial acidic hydrolysis and digestion with pectinase of acidic polysaccharides indicated that their carbohydrate backbone consists of alpha-1,4-linked residues of D-galacturonic acid. NMR spectra of acidic polysaccharides (fractions VO3-2 and VO3-3) confirmed this and demonstrated that their side oligosaccharide chains are composed of beta-1,4-linked galactopyranose residues and of terminal and 2,5- and 3,5-substituted residues of alpha-arabinofuranose at a Gal: Ara ratio of 3:1. Some polysaccharides from V. opulus were found to possess an immunostimulating activity: they enhance phagocytosis, in particular, the phagocytic index and the secretion of lysosomal enzymes with peritoneal macrophages. Calcium ions were found to be necessary for the appearance of the stimulating effect of acidic polysaccharides from V. opulus.
 ...
PMID:[The isolation, preliminary study of structure and physiological activity of water-soluble polysaccharides from squeezed berries of Snowball tree Viburnum opulus]. 1080 53

The effect of high-pressure treatment (200-600 MPa for 20 min) on the texture of cherry tomatoes and on the key softening enzymes (pectinmethylesterase and polygalacturonase) was investigated. When subjected to high-pressure treatment whole cherry tomatoes showed increasing textural damage with increasing pressures up to 400 MPa. However, treatment at pressures above 400 MPa (500-600 MPa) led to less apparent damage than treatment at 300 and 400 MPa; the tomatoes appearing more like the untreated samples. These visual changes were reflected in the texture (firmness) and amount of cell rupture in the tomatoes, with the least firmness and the most cell rupture being seen after treatment at 400 MPa. Light and scanning electron microscopy supported these observations. Although a sample of purified commercial pectinmethylesterase was partially inactivated at pressures above 200 MPa, irrespective of pH (4-9), in the whole cherry tomatoes no significant inactivation was seen even after treatment at 600 MPa, presumably because other components in the tomato offered protection or the isoenzymes were different. Polygalacturonase was more susceptible to pressure, being almost totally inactivated after treatment at 500 MPa. It is concluded that the textural changes in tomato induced by pressure involve at least two related phenomena. Initially, damage is caused by the greater compressibilty of the gaseous phase (air) compared to liquid-solid components, giving rise to a compact structure which, on pressure release, is damaged as the air rapidly expands, leading to increases in membrane permeability. This permits egress of water, and the damage also enables enzymatic action to increase, causing further cell damage and softening. The major enzyme involved in the further softening is polygalacturonase, which is inactivated at 500 MPa and above, and not pectinmethylesterase, which in the whole fruit, is barotolerant.
 ...
PMID:Effect of high-pressure treatment on the texture of cherry tomato. 1082 39

Polysaccharides from the roots of Panax ginseng were extracted by hot water and fractionated by using ethanol precipitation and ion exchange chromatography. Fractions FC (crude extract), F1 (fraction precipitated by ethanol), F1N (fraction unbound to DEAE-Sepharose CL-6B), and F1A (bound fraction) were obtained. Their carbohydrate analyses showed that acidic fraction F1A contains higher amounts of galactose, arabinose and uronic acids, in comparison to FC and F1. Fraction F1N mainly consists of glucose. The inhibition of Helicobacter pylori-induced hemagglutination revealed different inhibitory activities of these fractions. In particular, acidic fraction F1A showed a remarkable inhibitory activity (minimum inhibition concentration was 0.25 mg/ml) among the polysacharide fractions. However, digestion of the fraction F1A with pectinase resulted in a lower molecular weight oligosaccharide fraction F1AP which was non-inhibitory at the concentration of 4 mg/ml. Comparison of inhibitory activities and carbohydrate compositions of isolated fractions indicates that the activity correlated with the contents of galactose, arabinose, and uronic acids. These data suggest that acidic polysaccharides may be responsible for the inhibitory activity.
 ...
PMID:Inhibition of Helicobacter pylori hemagglutination by polysaccharide fractions from roots of Panax ginseng. 1082 Oct 45

Scanning electron microscopy (SEM) and chemical analysis were used to observe the cell wall changes that occur in cork with "mancha amarela", when compared to a standard cork. To mimic the microbial attack exhibited in cork with mancha amarela, the standard cork was treated enzymatically with commercial pectinase and hemicellulase preparations. The tissues treated with pectinase were comparable with those attacked with mancha amarela. Both were composed by deformed and wrinkly cells and exhibited cell wall separation at the middle lamella level, which suggests solubilization/removal of the pectic polysaccharides. The cork cell wall material, prepared as alcohol-insoluble residue, was fractionated by hot water (Pect(H)()2(O)) and hot dilute acid (Pect(acid)). The relatively large amount of hexuronic acid and the occurrence of Ara in the SPect(H)()2(O) and SPect(acid) allow to confirm, as far as we know, for the first time the presence of pectic polysaccharides in the cell walls of cork from Quercus suber L. They accounted for ca. 1.5% of the cork and may consist of polymers with long side chains of arabinosyl residues. These polymers have to be taken into account in any realistic model of the cork cell wall. Cork with mancha amarela contained a smaller amount of pectic polysaccharides (ca. 0.5%), which confirms that the cellular separation observed by SEM is related to the degradation/removal of the middle lamella pectic polysaccharides.
 ...
PMID:Demonstration of pectic polysaccharides in cork cell wall from Quercus suber L. 1088 89

The magnitude and diversity of the microbial population associated with dry (natural) processing of coffee (Coffea arabica) has been assessed during a 2-year period on 15 different farms in the Sul de Minas region of Brazil. Peptone water-washed samples were taken of maturing cherries on trees (cherries, raisins and dried cherries) and from ground fermentations. The microbial load varied from 3 x 10(4) to 2.2 x 10(9) cfu/cherry with a median value of 1.6 x 10(7) cfu/cherry. The microbial load increased after heavy rainfall on cherries that were drying on the ground. At all stages, bacteria were usually the most abundant group, followed by filamentous fungi and finally yeasts. Counts of bacteria, yeasts and fungi varied considerably between farms and at different stages of maturation and processing and no consistent pattern could be seen. Yeasts showed an increase during the fermentation process. Median counts were not significantly different for fungi, yeasts and bacteria between the 2 years although Gram-negative bacteria dominated in the wet year and Gram-positive bacteria dominated in the dry year. Of a total of 754 isolates, 626 were identified to at least genus level comprising 44 genera and 64 different species. The 164 isolates of Gram-negative bacteria included 17 genera and 26 species, the most common of which were members of the genera Aeromonas, Pseudomonas, Enterobacter and Serratia. Of 191 isolates of Gram-positive bacteria, 23 were spore-forming and included six Bacillus species, and 118 were non-spore-formers of which over half were Cellulomonas with lesser numbers of Arthrobacter, Microbacterium, Brochothrix, Dermabacter and Lactobacillus. Of the 107 yeast isolates, 90 were identified into 12 genera and 24 different species and almost all were fermentative. The most common genera, in decreasing frequency, were Pichia, Candida, Arxula and Saccharomycopsis. There were many rarely described yeasts including Pichia lynferdii and Arxula adeninivorans. Almost all 292 fungal isolates were identified to genus level and 52 were identified to species level. Cladosporium, Fusarium and Penicillium each comprised about one third of the isolates and were found on all farms. Only 3% of the isolates were Aspergillus. Beauvaria, Monilia, Rhizoctonia and Arthrobotrys species were also occasionally found. The microbial flora is much more varied and complex than found in wet fermentations. The genera and species identified include members known to have all types of pectinase and cellulase activities.
 ...
PMID:Microbial diversity during maturation and natural processing of coffee cherries of Coffea arabica in Brazil. 1101 14

We have studied macerated xylem of ferns, supplemented by sections, by means of scanning electron microscopy (SEM) in a series of 20 papers, the results of which are summarized and interpreted here. Studies were based mostly on macerations, but also on some sections; these methods should be supplemented by other methods to confirm or modify the findings presented. Guidelines are cited for our interpretations of features of pit membranes. Fern xylem offers many distinctive features: (1) presence of numerous vessels and various numbers of tracheids in most species; (2) presence of vessels in both roots and rhizomes in virtually all species; (3) presence of specialized end walls in vessels of only a few species; (4) multiple end-wall perforation plates in numerous species; (5) lateral-wall perforation plates in numerous species; (6) porose pit membranes associated with perforation plates in all species; and (7) pit dimorphism, yielding wide membrane-free perforations alternating with extremely narrow pits. Multiple end wall perforation plates and lateral wall perforation plates are associated with the packing of tracheary elements in fascicles in ferns: facets of tips of elements contact numerous facets of adjacent elements; all such contacts are potential sites for conduction by means of perforations. This packing differs from that in primary xylem of dicotyledons and monocotyledons. Porosities in pit membranes represent a way of interconnecting vessel elements within a rhizome or root. In addition, these porosities can interconnect rhizome vessel elements with those of roots, a feature of importance because roots are adventitious in ferns as opposed to those of vascular plants with taproots. Fully-formed or incipient (small-to-medium sized porosities in pit membranes) perforation plates are widespread in ferns. These are believed to represent (1) ease of lysis of pit membranes via pectinase and cellulase; (2) numerous potential sites for perforation plate formation because of fasciculate packing of tracheary elements; (3) evolution of ferns over a long period of time, so that lysis pathways have had time to form; (4) lack of disadvantage in perforation plate presence, regardless of whether habitat moisture fluctuates markedly or little, because ferns likely have maintaining integrity of water columns that override the embolism-confining advantage of tracheids. Although all ferns share some common features, the diversity in xylem anatomy discovered thus far in ferns suggests that much remains to be learned.
 ...
PMID:Vessels in ferns: structural, ecological, and evolutionary significance. 1115 21

An enzymatic method has been used to isolate, for the first time, polymeric suberin from the bark of Quercus suber L. or cork. This was achieved by solvent extraction (dichloromethane, ethanol and water), followed by a step-by-step enzymatic treatment with cellulase, hemicellulase and pectinase, and a final extraction with dioxane/water. The progress of suberin isolation was monitored by Fourier transform infrared spectroscopy using a photoacoustic cell (FTIR-PAS). The material obtained (polymeric suberin (PS)) was characterised by solid-state and liquid-state nuclear magnetic resonance, FTIR-PAS and vapour pressure osmometry, and compared with the suberin fraction obtained by alkaline depolymerisation (depolymerised suberin (DS)). The results showed that PS is an aliphatic polyester of saturated and unsaturated fatty acids, with an average molecular weight (M(w)) of 2050 g mol(-1). Although this fraction represents only 10% of the whole suberin of cork, its polymeric nature gives valuable information about the native form of the polymer. DS was found to have an average M(w) of 750 g mol(-1) and to comprise a significant amount of acidic and alcoholic short aliphatic chains.
 ...
PMID:Enzymatic isolation and structural characterisation of polymeric suberin of cork from Quercus suber L. 1116 27

Six different strains of yeast, namely Candida krusei, C. tropicalis, Pichia saitoi, Saccharomyces cerevisiae, P. anomala and Zygosaccharomyces bailii were found present in cassava-fermenting water in the early part of the fermentation. The latter part of the fermentation was dominated in all cases by three strains of yeast namely C. krusei, C. tropicalis and Z. bailii. All the yeast strains exhibited amylolytic capabilities while none was able to produce cellulase. All the strains except Zygosaccharomyces spp. exhibited polygalacturonase activity, but only C. krusei was able to produce linamarase. In a study on the inter-relationships between C. krusei and Lactobacillus plantarum, the growth of the yeast strain was not enhanced in cassava by the presence of the lactic acid bacteria, but the growth of the L. plantarum strain was significantly enhanced when co-inoculated with C. krusei.
 ...
PMID:Characteristics and significance of yeasts' involvement in cassava fermentation for 'fufu' production. 1139 90


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>