PECTIC ENZYME SYNTHESIS IN RELATION TO VIRULENCE IN FUSARIUM OXYSPORUM F. LYCOPERSICI (SACC.) SNYDER AND HANSEN

1962 ◽  
Vol 40 (4) ◽  
pp. 533-541 ◽  
Author(s):  
R. Paquin ◽  
L. J. Coulombe
Keyword(s):  
Fusarium Oxysporum ◽  
Virulent Strain ◽  
Pectin Methylesterase ◽  
Enzyme Synthesis ◽  
Pectic Enzyme ◽  
Pectic Enzymes ◽  
Cultural Conditions ◽  
Pectin Content

The pectic enzymes produced by Fusarium oxysporum f. lycopersici appear to be causally related to the virulence of the pathogen. The effects of various cultural conditions on the synthesis of pectin methylesterase by two strains of the pathogen were investigated. The virulent strain grew better and produced more pectic enzymes than the avirulent one, and this difference became even more pronounced in media with high pectin content and when the temperature of incubation was raised from 15° to 28 °C. The correlation between the virulence of the pathogen and the production of the pectic enzymes is discussed.

Pectic enzymes produced by Pseudomonas fluorescens, an organism associated with “pink eye” disease of potato tubers

1972 ◽  
Vol 50 (12) ◽  
pp. 2479-2488 ◽  
Author(s):  
S. S. Hagar ◽  
G. A. McIntyre
Keyword(s):  
Pseudomonas Fluorescens ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Pectin Methylesterase ◽  
Viscosity Reduction ◽  
Cellulose Acetate Electrophoresis ◽  
Pectic Enzymes ◽  
Ph Range ◽  
Two Peaks ◽  
Layer Chromatography

No pectin methylesterase (PME) activity was observed in crude or dialyzed extracts from macerated potato tuber tissue inoculated with Pseudomonas fluorescens; however, pectic lyase (syn. polygalacturonic acid transeliminase, PATE) activity was observed. Two PATE enzymes (peaks 1 and 2) were eluted from a pH 9.4 DEAE-cellulose column using a gradient of pH 7.6 Tris-HCl buffer (0.01–0.1 M). Enzyme in peak 1 was about 6 times more active than enzyme in peak 2 based on reducing group assays, and 10 times more active in viscosity reduction of 1% Na-polypectate (NaPP) at pH 8.5. No increase in absorbancy was observed at 515 nm of clarified reaction mixtures, indicating that saturated oligouronides did not accumulate. Other properties of the two peaks: optimum pH range was 8.5–9.5, substrate preference was NaPP vs. pectin, addition of Ca2+ (0.001 M) enhanced activity while EDTA (0.001 M) decreased activity to [Formula: see text], cellulose acetate electrophoresis revealed one band of protein per peak, and heat of inactivation was 51–60C. Thin-layer chromatography of hydrolytic products from NaPP revealed unsaturated uronides and pectic fragments after 2 h hydrolysis; after 96 h hydrolysis only unsaturated uronides were observed. Molecular weight estimations by Sephadex G-200 gel filtration were about 18 000 (peak 1) and 22 500 (peak 2). Enzyme in either peak macerated 400-μ sections of potato tissue.

scholarly journals Mathematical modeling for ethanol, methanol and acetaldehyde generation through Mexican carignane grape (Vitis vinifera) vinification process

Biotecnia ◽  
2021 ◽  
Vol 23 (3) ◽  
Author(s):  
Carmen María López-Saiz ◽  
Norma Violeta Parra-Vergara ◽  
María Esther Parra-Durazo ◽  
Manuel Sánchez-Lucero ◽  
Armando Burgos-Hernández ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Adverse Effects ◽  
Vitis Vinifera ◽  
Mathematical Models ◽  
Human Health ◽  
Fermentation Process ◽  
Heart Diseases ◽  
Process Temperature ◽  
Pectic Enzyme ◽  
Pectic Enzymes

Wine is a worldwide known beverage, and even though its consumption has been associated with the reduction of heart diseases and the extent of lifespan, it also has compounds that might cause adverse effects on human health such as methanol and acetaldehyde. The aim of this study was to determine the effect of time, temperature, and pectic enzymes over wine methanol and acetaldehyde concentrations during vinification. Three temperatures (20, 30, and 35 °C) and three pectic enzyme concentrations (0, 9, and 18 mL/Kg) were tested, letting fermentation to stop due to sugar depletion. Both, metanol and acetaldehyde were quantified throughout the fermentation process. Temperature reduced metanol production, observing the lowest metanol concentration (53.543 ± 3.267 mg/100 mL of wine) at 35 °C in the absence of pectic enzyme. Acetaldehyde was not affected by these variables. Alcohol, metanol, and acetaldehyde concentrations were adjusted to mathematical models with high correlations.

scholarly journals CULTIVATION OF SPIROCHÆTA GALLINARUM

1912 ◽  
Vol 16 (5) ◽  
pp. 620-628 ◽  
Author(s):  
Hideyo Noguchi
Keyword(s):  
Virulent Strain ◽  
Maximum Growth ◽  
Sudden Onset ◽  
Rabbit Kidney ◽  
Fresh Tissue ◽  
Cultural Conditions ◽  
Chicken Muscle ◽  
The Media ◽  
The Individual ◽  
Successive Generations

1. Spirochœta gallinarum can be cultivated in suitable artificial media for many successive generations and probably for indefinite periods. The presence of fresh tissue and a certain amount of oxygen seems to be essential for its growth. No perceptible odor is produced in the cultures. 2. The maximum growth of Spirochœta gallinarum is reached on about the fifth day, but the phase of degeneration commences slowly and gradually, so that in this respect the gallinarum differs from the duttoni, kochi, obermeieri, or novyi, whose cultures are characterized by sudden onset of degeneration soon after the maximum growth is attained. 3. No rod formation resembling bacilli arises in the course of multiplication of Spirochœta gallinarum in cultures. Many round or oval bodies appear in old cultures, but no infection of animals or formation of spiral forms from these granules has been produced. The granules are probably the degeneration products derived from the periblast of the spirochœtœ. 4. Cultures of Spirochœta gallinarum, either old or young, do not contain a form which passes through a Berkefeld filter (V) that infects chickens or grows into spirochætæ. 5. Spirochœta gallinarum remains virulent for chickens after being in cultures for at least thirteen generations, but it may become avirulent under certain cultural conditions. The inoculation of chickens with the attenuated culture renders the birds refractory to the subsequent infection with a virulent strain. 6. When the spirochætæ are cultivated in the media containing rabbit kidney instead of chicken muscle, the individual specimens are somewhat thicker, but otherwise typical. 7. Spirochœta gallinarum multiplies in culture by transverse division. No positive evidence of a longitudinal division has been obtained.

scholarly journals Genome-Wide Identification and Expression Analysis of Polygalacturonase Gene Family in Kiwifruit (Actinidia chinensis) during Fruit Softening

Plants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 327
Author(s):  
Wenjun Huang ◽  
Meiyan Chen ◽  
Tingting Zhao ◽  
Fei Han ◽  
Qi Zhang ◽  
...  
Keyword(s):  
Gene Family ◽  
Genetic Manipulation ◽  
Functional Characterization ◽  
Hydrolytic Enzyme ◽  
Pectin Methylesterase ◽  
Fruit Softening ◽  
Actinidia Chinensis ◽  
Separation Processes ◽  
Pectin Content ◽  
Pectin Lyases

Polygalacturonase (PG) is an essential hydrolytic enzyme responsible for pectin degradation and thus plays an important role in fruit softening and other cell separation processes. PG protein is encoded by a multigene family, however, the members of PG gene family in kiwifruit (Actinidia chinensis) have not been extensively identified. In this study, a total of 51 AcPG genes in kiwifruit genome were identified. They are phylogenetically clustered into seven clades, and of them AcPG4 and AcPG18 with other known PG genes involved in fruit softening from peach, pear, papaya and melon form a small cluster together. The members of kiwifruit PG gene family consist of three to nine exons and two to eight introns, and their exon/intron structures are generally conserved in all clades except the clade D and E. During fruit softening of kiwifruit ‘Donghong’ under ambient temperature, cell wall modifying enzymes, including PG, PL (pectate and pectin lyases), and PE (pectinesterase, also known as pectin methylesterase, PME) showed a different activity profile, and of them, PG and PE activities largely correlated with the change of pectin content and firmness. Moreover, only 11 AcPG genes were highly or moderately expressed in softening fruit, and of which three AcPG genes (AcPG4, AcPG18, and AcPG8, especially the former two) has been found to strongly correlate with the profile of PG activity and pectin content, as well as fruit firmness, suggesting that they maybe play an important role in fruit softening. Thus, our findings not only benefit the functional characterization of kiwifruit PG genes, but also provide a subset of potential PG candidate genes for further genetic manipulation.

scholarly journals Pectin Methylesterase Is Induced in Arabidopsis upon Infection and Is Necessary for a Successful Colonization by Necrotrophic Pathogens

2011 ◽  
Vol 24 (4) ◽  
pp. 432-440 ◽  
Author(s):  
Alessandro Raiola ◽  
Vincenzo Lionetti ◽  
Ibrahim Elmaghraby ◽  
Peter Immerzeel ◽  
Ewa J. Mellerowicz ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Pectin Methylesterase ◽  
Host Tissue ◽  
Pectobacterium Carotovorum ◽  
Pectic Enzymes ◽  
Pectate Lyases ◽  
Susceptibility Factor ◽  
Successful Colonization

The ability of bacterial or fungal necrotrophs to produce enzymes capable of degrading pectin is often related to a successful initiation of the infective process. Pectin is synthesized in a highly methylesterified form and is subsequently de-esterified in muro by pectin methylesterase. De-esterification makes pectin more susceptible to the degradation by pectic enzymes such as endopolygalacturonases (endoPG) and pectate lyases secreted by necrotrophic pathogens during the first stages of infection. We show that, upon infection, Pectobacterium carotovorum and Botrytis cinerea induce in Arabidopsis a rapid expression of AtPME3 that acts as a susceptibility factor and is required for the initial colonization of the host tissue.

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