Yeast Multi-Enzymatic Systems for Improving Colour Extraction, Technological Parameters and Antioxidant Activity of Wine.

Research Background: Wine yeasts are a heterogeneous microbial group with high enzymatic potential that makes them a useful tool in winemaking. With a better understanding of their oenological properties, selection procedures can be optimised to obtain more efficient strains. The present study aims to isolate and select yeasts from wine grape surface by studying their production of enzymes that hydrolyse plant cell wall polymers and by linking them to different technological parameters and antioxidant activity of wines.

Kinetic and metabolic behaviour of the pectinolytic strain Aureobasidium pullulans GM-R-22 during pre-fermentative cold maceration and its effect on red wine quality.

Pectinolytic yeasts can be applied to winemaking with the purpose of improving sensory and technological properties of wine because of their enzymes secreted during vinification. In this work, the autochthonous yeast-like pectinolytic strain from D.O.

Natural occurrence and production of tenuazonic acid in wine grapes in Argentina.

A survey was carried out to determine natural occurrence of tenuazonic acid (TA) in healthy and rotten wine grapes samples from different varieties ( = 37) collected during 2016 vintage in the region of DOC San Rafael (Argentina). In addition, inoculation experiments with three strains in wine grapes were done to elucidate TA production and its major influencing factors. The 16.

Isolation, identification and selection of antagonistic yeast against Alternaria alternata infection and tenuazonic acid production in wine grapes from Argentina.

Epiphytic isolates with yeast characteristics from grapes of the Malbec cultivar were obtained in order to find antagonists against Alternaria alternata. From a total of 111 isolates, 82% corresponded to the yeast-like organism Aureobasidium pullulans and the rest to the non-Saccharomyces yeasts Hanseniaspora uvarum (6.3%), Metschnikowia pulcherrima or spp.

Pectinolytic yeasts from viticultural and enological environments: novel finding of Filobasidium capsuligenum producing pectinases.

In this study indigenous yeasts associated with wineries, grapes and Malbec fermented must from San Rafael viticulture region (Argentina) were isolated to select pectinolytic strains for their potential use in enology. Pectinolytic yeasts were identified by physiological and molecular methods. Among 78 isolates, only nine were able to produce extracellular pectinases.

Isolation and selection of yeasts from wine grape ecosystem secreting cold-active pectinolytic activity.

The present study was undertaken with the purpose of selecting yeasts from wine grapes that are able to produce extracellular cold-active pectinases. After two consecutive selections yeast isolates were identified by pheno- and genotyping, and pectinolytic activity was preliminarily characterised at proximate winemaking conditions. Out of 1023 indigenous microorganisms isolated from grape skins of D.

Some factors affecting the adherence of probiotic Propionibacterium acidipropionici CRL 1198 to intestinal epithelial cells.

Adhesion to the intestinal mucosa is generally considered an important property of probiotic microorganisms and has been related to many of their health benefits. This study investigated some factors that could affect or be involved in the adherence of Propionibacterium acidipropionici CRL 1198, a dairy strain with suggested probiotic effects and high adherence in vitro and in vivo to intestinal epithelial cells. In vitro adhesion of propionibacteria was decreased by gastric digestion but not affected by bile and pancreatic enzymes.

Adhesion of dairy propionibacteria to intestinal epithelial tissue in vitro and in vivo.

Adhesion to the intestinal mucosa is a desirable property for probiotic microorganisms and has been related to many of their health benefits. In the present study, 24 dairy Propionibacterium strains were assessed with regard to their hydrophobic characteristics and their autoaggregation and hemagglutination abilities, since these traits have been shown to be indicative of adherence in other microorganisms. Six strains were further tested for their capacity to adhere to ileal epithelial cells in vitro and in vivo.

Acetaldehyde Production by Strains Used as Probiotics in Fermented Milk.

Lactic acid bacteria have diverse shunts for the metabolism of acetaldehyde, which is involved in the metabolism of carbohydrates, proteins and nucleic acids. In Lactobacillus acidophilus and Lactobacillus casei , strains isolated from feces of healthy children, acetaldehyde can be formed from different sources. Phosphotransacetilase, acetate kinase, aldehyde dehydrogenase and 2-deoxiriboaldolase activities were found in both strains.