Production and biochemical characterization of polygalacturonases produced byAureobasidium pullulans from forest soil

Abstract

The production of individual form of extracellular polygalacturonase by Aureobasidium pullulans from forest soil was found to depend on the pH of cultivation medium as well as on the nitrogen source in the precultivation or cultivation medium. Polygalacturonases were purified and characterized. The pH optima of polygalacturonases produced in the first phases of cultivation (24 or 48 h) and after 10 days as well as their molecular masses, isoelectric points, action pattern and ability to cleave polymeric and oligomeric substrates were different. Generally, polygalacturonases with random action pattern (EC 3.2.1.15) were produced only in the first phases of cultivation in acidic medium. The function of these enzymes for A. pullulans in the colonization of plant material rather than in the destruction of plant was hypothesized in physiological conditions. Exopolygalacturonases (EC 3.2.1.67) with terminal action pattern were produced in later phases of growth. Oligogalacturonate hydrolase as well as strongly basic polygalacturonase with unusual action pattern on substrates were found.

Antagonistic interactions between Aureobasidium pullulans and Fusarium culmorum, a fungal pathogen of winter wheat

“…The biotechnological potential of A. pullulans is also associated with its high enzymatic activity. Depending on temperature, type of fermentation, carbon source, pH and water availability, the isolates of A. pullulans produce endoglucanase, xylanase, beta-glucosidase (Leite et al 2008), polygalacturonases (Stratilová et al 2006), amylase (Li et al 2007;Manitchotpisit et al 2011) and chitinases (endochtinase, chitobiosidase) and beta-1,3-glucanase that is produced in culture and apple wounds (Castoria et al 2001). The enzymes produced by A. pullulans are involved in mode of action of this microrganism and play a key role in the biological control of plant diseases, suppressing the growth of phytopathogens.…”

Oligogalacturonate hydrolase with unique substrate preference from the pulp of parsley roots

“…The exoPGs of microbial origin favour oligomers of lower degree of polymerization (DP) (trimer or tetramer) (Heinrichová & Rexová-Benková 1976;Heinrichová et al 1993;Kester et al 1996;Stratilová et al 2006), digalacturonic acid (Hasegawa & Nagel 1968;van Rijssel et al 1993) or the substrate chain length is not a factor determining the enzyme effect (Musel & Strouse 1972). It was supposed that the most suitable substrates for exoPGs of plant origin are polymeric d-galacturonan (Heinrichová 1977) or a partially degraded d-galacturonan of DP about 20 (Hatanaka & Ozawa 1964;Pressey & Avants 1973).…”