Endo-polygalacturonase in wine yeasts: effect of carbon source on enzyme production

Abstract

Eight wine yeast strains of Saccharomyces sp. were tested for polygalacturonase (PGase) activity, after cultivation on various carbon sources. No strain showed any activity when grown on glucose, while five strains produced PGase in the presence of galactose and polygalacturonate. These data suggest that the PGase of wine strains is repressed by glucose and induced by galactose and polygalacturonate. The existence of the PGase gene in the wine strains and its similarity with that of the laboratory strains was proved by Southern hybridization and PCR amplification. The promoter region of the PGase gene in the wine strains was slightly different from that of the laboratory strains. This possibly explains the different pattern of gene expression in wine and laboratory strains. The PGase of wine strains produced di- or tri-galacturonic acid from polygalacturonic acid, different from the fungal PGase.

PGU1gene natural deletion is responsible for the absence of endo-polygalacturonase activity in some wine strains ofSaccharomyces cerevisiae

“…From 61 studied wine yeast strains, the authors found 52 strains showing an amplified band corresponding to the size of the PGU1 gene and, of these strains, only 36 were able to degrade polygalacturonic acid (pectin). Radoi et al (2005) also reported that the PGU1 gene might be absent from some strains, especially OC2, KW1 and L2226 (also confirmed by PCR and Southern analyses). The authors confirmed this observation using PCR and Southern blot analyses.…”

“…No amplification was obtained in 10 wine strains and in the BY4742pgu1D deletion mutant, whereas a clear band was amplified in all of the other strains screened (Fig. The absence of the PGU1 gene has already been described as a rare event (Fernandez-Gonzalez et al, 2004;Radoi et al, 2005). The absence of the PGU1 gene has already been described as a rare event (Fernandez-Gonzalez et al, 2004;Radoi et al, 2005).…”

“…At this stage, it was speculated that, in the negative strains, the phenotype may be the result of having a promoter-less PGU1 gene or a nonfunctional one (Blanco et al, 1998). However, the PGU1 promoter region was shown to exhibit very few mutations between various strains with low PGase activity and those with high PGase activity, and even with strains exhibiting no PGase activity (Hirose et al, 1999;Radoi et al, 2005). However, the PGU1 promoter region was shown to exhibit very few mutations between various strains with low PGase activity and those with high PGase activity, and even with strains exhibiting no PGase activity (Hirose et al, 1999;Radoi et al, 2005).…”

Production of Pectinolytic Enzymes by the Yeast Wickerhanomyces anomalus Isolated from Citrus Fruits Peels

“…Eight wine yeast strains of Saccharomyces sp. produced PG but none of them produced PL or PAL [19]. Masoud and Jespersen [20] reported that yeasts predominant during coffee processing (six strains of Pichia anomala , four strains of P. kluyveri, and two strains of Hanseniaspora uvarum ) were found to secrete PG but no PL or PE was found to be produced by the yeasts examined.…”

Characterization of an Exopolygalacturonase from Aspergillus niger

“…PG is produced by plants [3,4] and by microorganisms such as bacteria and fungi [5][6][7], but only a few yeast species show this ability [8,9]. In relation to their activity, PG cleaving α- [1,4]-glycosidic bonds of nonesterified galacturonic acid residues are classified as endoPG (EC 3.2.1.15) and exoPG (EC 3.2.1.67).…”