Multiple forms of pectic lyases and polygalacturonase from Fusarium oxysporum f,.sp. radicis lycopersici: regulation of their synthesis by galacturonic acid

1997 ◽  
Vol 43 (3) ◽  
pp. 245-253 ◽  
Author(s):  
M. A. Guevara ◽  
P. Estévez ◽  
M. T. González-Jaén
Keyword(s):  
Fusarium Oxysporum ◽  
Galacturonic Acid ◽  
Pectate Lyase ◽  
Pectin Lyase ◽  
Multiple Forms ◽  
Pectic Enzymes ◽  
Weak Preference ◽  
Absolute Requirement ◽  
Lyase Activity ◽  
Polygalacturonase Activity

The r2 isolate of Fusarium oxysporum f.sp. radicis-lycopersici produced several pectic enzymes that differ in substrate preference, reaction mechanism, and action pattern. We detected three forms that have lyase activity, four forms with polygalacturonase activity and one form with pectinesterase activity. Lyases had an absolute requirement for calcium and pIs of 9.20, 9.00, and 8.65. The two more alkaline forms had a weak preference for pectin, whereas the other was more active on polygalacturonate. Polygalacturonases had pIs of 9.30, 7.35, 6.85, and 6.55 and were inhibited by calcium ions. Lyases and polygalacturonases were induced by galacturonic acid and were subject to catabolite repression. Induced synthesis occurred at pHs 5.5 and 8.0 and no increase in lyase activities were promoted by alkalinization of cultures. Pectin lyase had an endo mode of action, whereas pectate lyase and polygalacturonase behaved more as exoenzymes. These results are discussed in relation to the appearance of the different pectic enzymes when the fungus is confronted with a pectic polymer.Key words: Fusarium oxysporum f.sp. radicis-lycopersici, Lycopersicon esculentum, pectate lyase, pectin lyase, polygalacturonase.

Evidence against involvement of pectic enzymes in the invasion of root hairs by Rhizobium trifolii

1969 ◽  
Vol 15 (6) ◽  
pp. 643-645 ◽  
Author(s):  
James D. Macmillan ◽  
Roderic C. Cooke
Keyword(s):  
Root Hairs ◽  
Red Clover ◽  
Infection Process ◽  
Pectin Lyase ◽  
Rhizobium Trifolii ◽  
Leguminous Plants ◽  
Pectic Enzymes ◽  
Lyase Activity ◽  
Rhizobium Spp ◽  
Polygalacturonate Lyase

It has been postulated that polygalacturonase is significant in the infection of root hairs of leguminous plants by Rhizobium spp. Recently this theory has been strongly questioned. Evidence for polygalacturonase was based on methods which would not distinguish between this enzyme and other pectic glycosidases. The possibility that pectin lyase or polygalacturonate lyase is involved in the invasion of red clover by Rhizobium trifolii was investigated. Weak pectin lyase activity was detected in uninoculated seedlings, but no increase in the activity was produced in inoculated seedlings. It was concluded that neither of the lyases has significance in the infection process.

Purification and characterization of an extracellular exopolygalacturonase from Geotrichum lactis

1991 ◽  
Vol 37 (12) ◽  
pp. 974-977 ◽  
Author(s):  
C. Pardo ◽  
M. A. Lapeña ◽  
M. Gacto
Keyword(s):  
Molecular Weight ◽  
Galacturonic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Pectic Enzymes ◽  
Ammonium Sulphate Precipitation ◽  
Polygalacturonase Activity ◽  
Single Enzyme

Geotrichum lactis ATCC 48590 produced extracellular polygalacturonase (EC 3.2.1.67) in media containing pectate, pectin, or galacturonic acid as inducers. The synthesis of the enzyme was strongly repressed by glucose. The polygalacturonase was purified 80-fold by ammonium sulphate precipitation, Sephadex G-100 filtration, and DEAE Sephadex ion-exchange chromatography. Polyacrylamide gel electrophoresis with copolymerized substrate indicated that the isolated material was a single enzyme with polygalacturonase activity. The main product of enzyme action was galacturonic acid. The enzyme shows a molecular weight close to 53 000 by gel filtration and degrades preferentially de-esterified substrates. Km values for pectate and pectin (64% esterified) were 0.09 and 0.49 mg mL−1, respectively. The optimum pH for enzyme activity was 5.0, while the optimum temperature was 40 °C. The polygalacturonase was precipitated by concanavalin A – Sepharose, and treatment with endoglycosidase H reduced its precipitation by the lectin, suggesting that the enzyme is a glycoprotein. In addition to being found extracellularly, the polygalacturonase is also present in the periplasm of the cells. A different form of the polygalacturonase showing a lower molecular weight was located inside the cells. Key words: polygalacturonase, pectic enzymes, Geotrichum lactis.

Production and Thermal Characterization of an Alkaline Pectin Lyase from Penicillium notatum

2015 ◽  
Vol 11 (4) ◽  
pp. 517-525 ◽  
Author(s):  
Umme Habibah Siddiqua ◽  
Haq Nawaz Bhatti ◽  
Shazia Nouren ◽  
Saima Noreen ◽  
Ismat Bibi
Keyword(s):  
Ammonium Sulphate ◽  
Thermal Inactivation ◽  
Thermal Characterization ◽  
Maximal Activity ◽  
Inhibitory Effect ◽  
Pectin Lyase ◽  
Partial Purification ◽  
Penicillium Notatum ◽  
Enhanced Production ◽  
Lyase Activity

Abstract The present study was aimed to investigate the potential of Penicillium notatum for the production of pectin lyase under solid state culture using wheat bran as substrate. Different process parameters were optimized using completely randomized design for enhanced production of the pectin lyase. P. notatum showed maximum production (1875 U/gds) of pectin lyase with substrate amount 15 g/250 ml, moisture level 60%, pH 6, incubation period 120 h at 30°C. Pectin lyase activity was further improved with the addition of maltose and ammonium sulphate as carbon and nitrogen additives (1%), respectively. Partial purification of enzyme was carried out by ammonium sulphate precipitation at 80% saturation level. The P. notatum pectin lyase showed maximal activity at 65°C and pH 8. Km and Vmax values were 0.29% and 0.487 µmol/min, respectively. Energy of activation was found to be 5.33 kJ/mol. A detailed kinetic study of thermal inactivation was carried out. The results showed that pectin lyase exhibited resistance against thermal unfolding. Effect of various metals on pectin lyase activity was also investigated. All the metals showed inhibitory effect on the enzyme activity. The present investigation revealed that pectin lyase isolated from P. notatum is thermally stable and alkaline in nature.

Pectin Lyase Activity in Culture Medium of Lasidioplodia theobromae

2007 ◽  
Vol 2 (3) ◽  
pp. 334-340 ◽  
Author(s):  
A.O. Adejuwon ◽  
P.O. Olutiola .
Keyword(s):  
Culture Medium ◽  
Pectin Lyase ◽  
Lyase Activity

Characteristics of the immobilized pectin lyase activity from a commercial pectolytic enzyme preparation

1990 ◽  
Vol 10 (6) ◽  
pp. 531-539 ◽  
Author(s):  
P. Lozano ◽  
A. Manjón ◽  
J. L. Iborra ◽  
D. M. Gálvez
Keyword(s):  
Enzyme Preparation ◽  
Pectin Lyase ◽  
Lyase Activity ◽  
Pectolytic Enzyme

scholarly journals The Homogalacturonan Deconstruction System of Paenibacillus amylolyticus 27C64 Requires No Extracellular Pectin Methylesterase and Has Significant Industrial Potential

2020 ◽  
Vol 86 (12) ◽  
Author(s):  
Christian Keggi ◽  
Joy Doran-Peterson
Keyword(s):  
Plant Cell ◽  
Plant Cell Wall ◽  
Pectate Lyase ◽  
Pectin Methylesterase ◽  
Pectin Lyase ◽  
Cell Wall Polysaccharide ◽  
Positive Bacterium ◽  
High Turnover ◽  
Gram Positive ◽  
Content Type

ABSTRACT Paenibacillus amylolyticus 27C64, a Gram-positive bacterium with diverse plant cell wall polysaccharide deconstruction capabilities, was isolated previously from an insect hindgut. Previous work suggested that this organism’s pectin deconstruction system differs from known systems in that its sole pectin methylesterase is cytoplasmic, not extracellular. In this work, we have characterized the specific roles of key extracellular pectinases involved in homogalacturonan deconstruction, including four pectate lyases and one pectin lyase. We show that one newly characterized pectate lyase, PelC, has a novel substrate specificity, with a lower Km for highly methylated pectins than for polygalacturonic acid. PelC works synergistically with PelB, a high-turnover exo-pectate lyase that releases Δ4,5-unsaturated trigalacturonate as its major product. It is likely that PelC frees internal stretches of demethylated homogalacturonan which PelB can degrade. We also show that the sole pectin lyase has a high kcat value and rapidly depolymerizes methylated substrates. Three cytoplasmic GH105 hydrolases were screened for the ability to remove terminal unsaturated galacturonic acid residues from oligogalacturonide products produced by the action of extracellular lyases, and we found that two are active on demethylated oligogalacturonides. This work confirms that efficient homogalacturonan deconstruction in P. amylolyticus 27C65 does not require extracellular pectin methylesterase activity. Three of the extracellular lyases studied in this work are also thermostable, function well over a broad pH range, and have significant industrial potential. IMPORTANCE Pectin is an important structural polysaccharide found in most plant cell walls. In the environment, pectin degradation is part of the decomposition process that turns over dead plant material and is important to organisms that feed on plants. Industrially, pectinases are used to improve the quality of fruit juices and can also be used to process coffee cherries or tea leaves. These enzymes may also prove useful in reducing the environmental impact of paper and cotton manufacturing. This work is significant because it focuses on a Gram-positive bacterium that is evolutionarily distinct from other well-studied pectin-degrading organisms and differs from known systems in key ways. Most importantly, a simplified extracellular deconstruction process in this organism is able to break down pectins without first removing the methyl groups that inhibit other systems. Moreover, some of the enzymes described here have the potential to improve industrial processes that rely on pectin deconstruction.

Cell wall degrading enzymes in fusarium wilt of chickpea: correlation between pectinase and xylanase activities and disease development in plants infected with two pathogenic races of Fusarium oxysporum f. sp. ciceris

2006 ◽  
Vol 84 (9) ◽  
pp. 1395-1404 ◽  
Author(s):  
Inmaculada Jorge ◽  
Juan A. Navas-Cortés ◽  
Rafael M. Jiménez-Díaz ◽  
Manuel Tena
Keyword(s):  
Cell Wall ◽  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Specific Activity ◽  
Gel Filtration ◽  
Pectate Lyase ◽  
Disease Development ◽  
In Planta ◽  
Cell Wall Degrading Enzymes ◽  
Degrading Enzymes

Production of cell wall degrading enzymes (CWDEs) polygalacturonase (PG), pectate lyase (PL), and xylanase was studied in chickpeas ( Cicer arietinum L. ‘P-2245’) inoculated with Fusarium oxysporum f. sp. ciceris (Padwick) Matuo & K. Sato races 0 (mildly virulent, causing a yellowing syndrome) and 5 (highly virulent, causing a wilting syndrome) by the water-culture method. These CWDEs were similarly produced in both syndromes. PG and PL were the only enzymes occurring in roots and stems and attained the highest specific activity, this being generally higher for race 5 than for race 0. Gel filtration chromatography revealed a similar complement of in planta expressed pectinase isoforms, dominated by an endo-PG and two endo-PLs, the endo-PLs being differentially expressed by the two races. CWDE activities in roots and stems were positively correlated with development of yellowing and wilting. Exceptions to this were PG in stems, which was negatively correlated with the development of yellowing, and PG in roots, which showed a negative trend with development of either syndrome. The levels of CWDEs that significantly correlated with disease development were adequately described by exponential functions of disease progress. Results have implications for the role played by CWDEs in the early and later stages of pathogenesis in chickpea fusarium wilt.

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