Perspectives in the biological function and the technological application of polygalacturonases

Abstract

Polygalacturonases (PG) have evolved in the past years from a pectinase "simply" being used for food processing to an important parameter in plant-fungal interaction. PG-inhibiting proteins (PGIP) that are synthesised in plants as a specific response to PGs of pathogenic fungi, have become a focus as a possible target in resistance breeding, and PGIPs are also a concern as an inhibiting factor in food processing. Plant PGs have been identified as a major factor in fruit ripening, and PG-deficient transgenic plants have been bred. Mainly fungal PGs are used in industrial processes for juice clarification and the range of enzymes is being extended through new recombinant and non-recombinant fungal strains. Finally, novel fields of application can be envisaged for PGs in the production of oligogalacturonides as functional food components. Here we aim to highlight the various fields where PGs are encountered and where they are of biological or technological importance.

Microbial strain improvement for enhanced polygalacturonase production by Aspergillus sojae

“…In some food processes, it is convenient to use only one type of pectinolytic enzymes, e.g. preparation of instant potato flakes and carrot juice for baby food requires the maceration, where vitamins, colour and aroma have to be preserved and for these applications preparations that mainly contain PG activity are preferred (Lang and Dörnenburg 2000).…”

Isolamento e seleção de microrganismos pectinolíticos a partir de resíduos provenientes de agroindústrias para produção de aromas frutais

“…De 104 linhagens testadas, 18 foram selecionadas para fermentarem em meio líquido, contendo pectina para a determinação de atividade de poligalacturonase (PG) e de pectina liase (PMGL), e em meio frutose/extrato de levedura para produção de aromas. As linhagens 2, 9, 20, 39, 70, 74 e 99 apresentaram unidades de atividade de PG superiores a 80 µmol de ácido galacturônico/mL/min, as linhagens 17, 18,31,37, 73, 74 e 125 apresentaram unidades de atividade de PMGL superiores a 1000 ηmol de produtos insaturados/ mL/min e as linhagens 13, 70, 73, 74, 125 e 144 apresentaram os melhores descritores e as maiores intensidades de aromas percebidos por um painel não treinado de provadores. Palavras-chave: pectina, fermentação, pectinase, poligalacturonase, pectina liase, aroma.…”

Kinetic study on inducibility of polygalacturonases from Aspergillus flavipes FP-500

“…The importance of pectin-degrading enzymes lies mainly in their actual and potential uses in a number of industries, like in food processing, textile industry, paper and pulp industry, pectic wastewater treatment and animal feed, among others (Jayani et al 2005;Niture, 2008). In addition, the understanding of the regulation process of the production of polygalacturonases will contribute to get insights in the molecular dialogue between the host and the pathogen, during microbial invasion of plant cell wall (Esquerré-Tugayé et al 2000;Lang and Dörnenburg, 2000).…”