Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.15 (pectinase)
2,440 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A yeast strain secreting endopolygalacturonase was used in this work to study the possibility of continuous production of this enzyme. It is a feasible and interesting alternative to fungal batch production essentially due to the specificity of the type of pectinase excreted by Kluyveromyces marxianus CCT 3172, to the lower broth viscosity and to the easier downstream operations. In order to increase the reactors' productivity, a cellulosic carrier obtained from barley spent grains was tested as an immobilization support. Two types of reactors were studied for pectinase production using glucose as a carbon and energy source--a continuous stirred tank reactor (CSTR) and a packed bed reactor (PBR) with recycled flow. The highest value for pectinase volumetric productivity (P(V)=0.98 U ml(-1) h(-1)) was achieved in the PBR for D=0.40 h(-1), a glucose concentration on the inlet of S(in)=20 g l(-1), and a biomass load in the support of X(i)=0.225 g g(-1). The results demonstrate the attractiveness of the packed bed system for pectinase production.
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PMID:Continuous production of pectinase by immobilized yeast cells on spent grains. 1623 66

Studies were carried out on the production of pectinases using deseeded sunflower head by Aspergillus niger DMF 27 and DMF 45 in submerged fermentation (SmF) and solid-state fermentation (SSF). Higher titres of endo- and exo-pectinases were observed when medium was supplemented with carbon (4% glucose for SmF and 6% sucrose for SSF) and nitrogen (ammonium sulphate, 0.3% for both SmF and SSF) sources. Green gram husk proved to be relatively a better supplement to attain higher yield of endo-pectinase (11.7 U/g) and exo-pectinase (30.0 U/g) in solid-state conditions. Maximum production of endo-pectinase (19.8 U/g) and exo-pectinase (45.9 U/g) by DMF 45 were recorded in SSF when compared to endo-pectinase (18.9 U/ml) and exo-pectinase (30.3 U/ml) by DMF 27 in SmF under optimum process conditions.
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PMID:Production of pectinase from deseeded sunflower head by Aspergillus niger in submerged and solid-state conditions. 1626 74

Wines by yeast mutants producing polygalacturonase in high glucose concentration, from Saccharomyces wine-making strains, had higher filterability and more concentrated anthocyanin contents than that of their parent strains. These results suggest that the clarification process was improved at a lower cost by the low viscosity and that high-quality wines result from the increase in the anthocyanin contents.
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PMID:Characteristics of wines made by Saccharomyces mutants which produce a polygalacturonase under wine-making conditions. 1630 7

Growth and concomitant production of an extracellular pectin lyase (PL) [poly(methoxylgalactosiduronate) endolyase; EC 4.2.2.10] were investigated in a group of 16 fungi grown in liquid medium containing pectin as a supplementary carbon source. Culture filtrates of both Penicillium italicum (CECT 2294) and P. expansum (CECT 2275) showed the highest PL activity and contained polygalacturonase but not pectinesterase activity. The effect of the inoculum size, the carbon source (sucrose and glucose syrup), and the presence of pectin on the production of PL by P. italicum was studied. The presence of 2.6 mM glycerophosphate in the culture medium enhanced the appearance of PL but was not inhibitory for the in vitro activity. However, glycerol inhibited the enzyme nearly 50% at such a concentration.
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PMID:Pectin Lyase Production by a Penicillium italicum Strain. 1634 54

The range of polysaccharide-degrading enzymes and glycosidases formed by the phytopathogenic fungus Sclerotinia sclerotiorum was monitored following growth on 16 carbohydrate substrates. Endo- and exoenzymes capable of degrading cellulosic, hemicellulosic, and pectinolytic polysaccharides were secreted. Pectinolytic activities were produced constitutively on all of the substrates tested. Cellulolytic enzymes were not induced in simple sugar (i.e., glucose or xylose) media. Polysaccharide growth substrates and cellulase inducers increased all of the enzyme activities tested. Gel filtration analysis revealed the appearance of new molecular forms of pectinase, beta-xylosidase, and cellobiosidase during induction on pectin and carboxymethyl cellulose media.
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PMID:Production of Cell Wall-Degrading Enzymes by the Phytopathogenic Fungus Sclerotinia sclerotiorum. 1634 87

Pink yeasts identified as Rhodotorula glutinis var. glutinis, R. minuta var. minuta, and R. rubra produce polygalacturonases which cause a slow softening of olive tissue. Both pectin methyl esterase and polygalacturonase are produced when cultures are grown in appropriate media. Crude, cell-free dialyzed enzyme preparations measured viscosimetrically exhibited optimal activity on sodium polygalacturonate at pH 6.0 and 40 C, and were active in the range of pH 4.0 to 9.0 and 10 to 50 C. Cultures grown in sterilized olives and brine at pH 4.0 with sterile glucose added aseptically caused a slow softening of tissue as measured with a Christel texturometer. Similar results were obtained when crude, cell-free enzyme preparations were added to olives in buffer solution at pH 6.0 with Merthiolate. Commercial control of these yeasts is easy if anaerobic conditions can be provided. Otherwise, the industry has to resort to manual removal of the film from the brine surface, either by skimming or by flagellation.
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PMID:Some pink yeasts associated with softening of olives. 1634 64

The production of endopolygalacturonase (endoPG) by Colletotrichum lindemuthianum, a fungal pathogen causing anthracnose on bean seedlings, was enhanced when the fungus was grown in liquid medium with L-arabinose or L-rhamnose as the sole carbon source. These two neutral sugars are present in plant cell wall pectic polysaccharides. The endolytic nature of the enzyme was demonstrated by its specific interaction with the polygalacturonase-inhibiting protein of the host plant as well as by sugar analysis of the products released from its action on oligogalacturonides. Additional characterization of the protein was achieved with an antiserum raised against the pure endoPG of the fungus. Induction by arabinose and rhamnose was more prolonged and led to a level of enzyme activity at least five times higher than that on pectin. Northern blot experiments showed that this effect was correlated to the induction of a 1.6-kb transcript. A dose-response study indicated that the endoPG transcript level was already increased at a concentration of each sugar as low as 2.75 mM in the medium and was maximum at 55 mM arabinose and 28 mM rhamnose. Glucose, the main plant cell wall sugar residue which is also present in the apoplast, prevented endoPG gene expression, partially when added to pectin at concentrations ranging from 5 to 110 mM and totally when added at 55 mM to arabinose. Inhibition by glucose of the rhamnose-induced endoPG was correlated to nonuptake of rhamnose. This is the first report that arabinose and rhamnose stimulate endoPG gene expression in a fungus. The possible involvement of these various sugars on endoPG gene expression during pathogenesis is discussed.
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PMID:Induction by (alpha)-L-Arabinose and (alpha)-L-Rhamnose of Endopolygalacturonase Gene Expression in Colletotrichum lindemuthianum. 1653 26

The molecular structure, chemical properties, and biological function of the xyloglucan polysaccharide isolated from cell walls of suspension-cultured sycamore (Acer pseudoplatanus) cells are described. The sycamore wall xyloglucan is compared to the extracellular xyloglucan secreted by suspension-cultured sycamore cells into their culture medium and is also compared to the seed "amyloid" xyloglucans.Xyloglucan-or fragments of xyloglucan-and acidic fragments of the pectic polysaccharides are released from endopolygalacturonase-pretreated sycamore walls by treatment of these walls with 8 m urea, endoglucanase, or 0.5 n NaOH. Some of the xyloglucan thus released is found to cochromatograph with the acidic pectic fragments on diethylaminoethyl Sephadex. The chemical or enzymic treatments required for the release of xyloglucan from the walls and the cochromatography of xyloglucan with the acidic pectic fragments indicate that xyloglucan is covalently linked to the pectic polysaccharides and is noncovalently bound to the cellulose fibrils of the sycamore cell wall.The molecular structure of sycamore xyloglucan was characterized by methylation analysis of the oligosaccharides obtained by endoglucanase treatment of the polymer. The structure of the polymer is based on a repeating heptasaccharide unit which consists of 4 residues of beta-1-4-linked glucose and 3 residues of terminal xylose. A single xylose residue is glycosidically linked to carbon 6 of 3 of the glucosyl residues.
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PMID:The Structure of Plant Cell Walls: II. The Hemicellulose of the Walls of Suspension-cultured Sycamore Cells. 1665 81

Turnover of cell wall polysaccharides and effects of auxin thereon were examined after prelabeling polysaccharides by feeding pea (Pisum sativum var. Alaska) stem segments (14)C-glucose, then keeping the tissue 7 hours in unlabeled glucose with or without indoleacetic acid. There followed an extraction, hydrolysis, and chromatography procedure by which labeled monosaccharides and uronic acids were released and separated with consistently high recovery. Most wall polymers, including galacturonan and cellulose, did not undergo appreciable turnover. About 20% turnover of starch, which normally contaminates cell wall preparations but which was removed by a preliminary step in this procedure, occurred in 7 hours. Quantitatively, the principal wall polymer turnover process observed was a 50% decrease in galactose in the pectinase-extractable fraction, including galactose attached to a pectinase-resistant rhamnogalacturonan. Other pectinase-resistant galactan(s) did not undergo turnover. No turnover was observed in arabinans, but a doubling of radioactivity in arabinose of the pectinase-resistant, hot-acid-degradable fraction occurred in 7 hours, possibly indicating conversion of galactan into arabinan. None of the above changes was affected by indoleacetic acid, but a quantitatively minor turnover of a pectinase-degradable xyloglucan was found to be consistently promoted by indole-acetic acid. This was accompanied by a reciprocal increase in water-soluble xyloglucan, suggesting that indoleacetic acid induces conversion of wall xyloglucan from insoluble to water-soluble form. The results indicate a highly selective pattern of wall turnover processes with an even more specific influence of auxin.
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PMID:Turnover of cell wall polysaccharides in elongating pea stem segments. 1665 65

Production of carbohydrases by Alternaria solani is inhibited by glucose under low growth conditions. In an enriched medium, glucose has little effect on the production of polygalacturonase and cellulase while it still suppresses production of beta-glucosidase. Low levels of all three enzymes were produced in the absence of their respective substrates. Such regulation has been found with many organisms. However, far greater production of these carbohydrases occurred with additions of adenosine phosphates to the growth media. Highest stimulation of enzyme production was by adenosine 5'-phosphate. Adenosine 5'-triphosphate and cyclic 3', 5'-adenosine monophosphate gave lesser amounts. Starvation appears to induce production of extracellular carbohydrases and adenosine 5'-phosphate may have a role in the starvation process.
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PMID:Effect of Glucose and Adenosine Phosphates on Production of Extracellular Carbohydrases of Alternaria solani. 1665 49


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