Properties Of Polygalacturonase Research Articles

Inactivation kinetics and thermodynamic properties of polygalacturonase produced by Aspergillus awamori CICC 2040 on pretreated orange and plantain peels

This study investigated the effect of pretreatment of orange and plantain peels on the inactivation kinetics and thermodynamic properties of polygalacturonase (PG) produced by Aspergillus awamori CICC 2040. Orange and plantain peel powders were subjected to microwave-assisted NaOH pretreatment and used as substrates for PG production. Un-treated peels served as controls. The PG was purified using acetone precipitation and column chromatography, and the inactivation kinetics, temperature dependency, and thermodynamic properties of the crude and purified PGs were determined. Higher inactivation rate constant was obtained for crude PG produced using pretreated orange peel (CPOF) and plantain peel (CPPF) compared to PG produced using untreated orange peel (Uo) and plantain peel (Up). At all the temperatures considered, higher half-life and decimal reduction time were recorded for CPOF and CPPF compared to Uo and Up. The highest half-life (45.60 min) and decimal reduction time (151.49 min) were recorded for CPOF at 60 ?C. Lower half-life and decimal reduction time were obtained for purified PGs compared to the crude PG. Polygalacturonase produced from pretreated peels had lower activation energy than those produced from untreated ones. The higher activation energy was recorded for the PG produced using orange peel compared to the one from plantain peels. The enthalpy of CPOF and CPPF was slightly lower than Uo and Up. The pretreatment of the peels resulted in a reduction of Gibbs free energy (?G ) and entropy (?S) of crude and purified PG. Higher ?G and ?S were recorded for the purified PG compared to the crude PG. Negative entropy and enthalpy were recorded for all the PGs. The findings from this study showed that the kinetic and thermodynamic properties of PG, produced by Aspergillus awamori CICC 2040, were enhanced by the pretreatment of orange and plantain peels.

Preliminary investigations on a polygalacturonase from Aspergillus fumigatus in Chinese Pu’er tea fermentation

Abstract Background Polygalacturonase is one kind of pectinases which hydrolyze the alpha-1,4 glycosidic bond between galacturonic acid residue. Polygalacturonase has been widely used in the fields of food, biofuel, and textile industries, in which thermostable polygalacturonase is often demanded at high temperatures of 50–60 °C. Herein, we reported a thermostable polygalacturonase producing from Aspergillus fumigatus isolated from the pile fermentation of Pu’er tea in China. Results The thermophilic polygalacturonase-producing strain was identified as A. fumigatus L45 on basis of its morphology, physicochemical properties, and 18S rDNA analysis. The crucial fermentation parameters affecting polygalacturonase activity were optimized by response surface methodology (RSM); the optimum fermentation parameters were the following: inoculums concentration of 0.07 % (v/v), fermentation time of 36 h, pH of 5.0, and temperature of 45 °C. Under the optimized conditions, the highest polygalacturonase activity of 359.1 ± 10.1 U/mL was obtained. The polygalacturonase showed good thermostability and pH stability. The enzyme was activated by metal ions Zn2+ and Mg2+, but inhibited by K+. However, Na+ and Ca2+ showed little effects on its activity. K m and V max values were estimated to be 35.0 mg/mL and 7.69 μmol/mL/min, respectively. Conclusions A polygalacturonase from A. fumigatus L45 was preliminarily investigated, the crucial fermentation parameters were optimized by RSM, and the properties of polygalacturonase was examined. The polygalacturonase showed good thermostability and pH stability, which suggested the enzyme has potential applications in the biofuel and textile industries.

Data Analysis on Properties of Polygalacturonase Purified and Separated From Kiwifruit

In this study, characteristics and enzyme activities of Polygalacturonase Purified and Separated from kiwifruit were studied. The study used chemical analysis and computer data analysis methods to make clear the best reaction temperature, best pH value to keep the Polygalacturonase activity and the inhibition activity of Polygalacturonase on certain metal ions were also investigated. The experiments results showed that the best temperature ranges for keeping enzyme activity were 30-50°C and the best pH value ranges were pH4.5-6.5. And the tests also showed that Polygalacturonase has obvious inhibition activities for many metal ions.

Isolation and characterization of polygalacturonase and invertase from a yeast Endomycopsis fibuligera (3812) bioconversion of date wastes

Properties of polygalacturonase [E.C. 3.2.1.15] (E1) and invertase (E.C. 3.2.1.26] (E2) isolated and purified in powdered form from Endomycopsis fibuligera grown on date wastes were measured.The molecular weights were estimated to be about 32000 and 69500, and they were highly specific for hydrolysing (1–4) and (1–2) glycosidic links respectively. the Km value of E1 was 7.1 × 10‐2M for soluble‐pectic acid and that for E2 was 6.7 × 10‐2M for sucrose at pH4.5, and optimal pHs were 3.5 for E1 and 4.0 for E2. the purified enzymes are stable on storage for more than one year at ‐ 20°C.

Occurrence and Properties of Polygalacturonase in Avena and Other Plants

Polygalacturonase activity has been detected in a number of plants including seedlings of Phaseolus vulgaris, Zea mays, Avena sativa, and Pisum sativum. Particular emphasis was placed on characterizing the enzyme from oat seedlings. This enzyme is solubilized by 0.2 m NaCl, and its activity is highest near the apical tips of oat coleoptiles. It has a pH optimum between 5 and 5.5 and is activated by Ca(2+), with an optimal concentration of 0.4 mm. Cd(2+) also activates the enzyme but less effectively than Ca(2+). The rate of attack is maximal for substrates with chain lengths of about 20 units and slowest for digalacturonate. The oat enzyme hydrolyzes galacturonans by removing galacturonic acid units from the nonreducing ends and progressively shortens the substrate chains.