Ecology and technological capability of lactic acid bacteria isolated during Grillo grape vinification in the Marsala production area.

Grapes of “Grillo” variety, used to produce Marsala wine, were harvested from five vineyards different for climatic and agronomic parameters, in order to obtain a first mapping of lactic acid bacteria (LAB) inhabiting the production area. Marsala base wine production was followed at large-scale and two experimental vinifications, different for lysozyme and SO2 concentration and combination, were carried out at pilot-plant scale. LAB communities and conventional chemical parameters were periodically analysed. LAB were found on grapes at an average concentration of about 102 CFU g-1 which decreased during the transformation process. A total of 146 colonies were collected, but only 35 were recognized as presumptive LAB. On the basis of phenotypic differences and isolation source, 16 isolates were then subjected to genotypic identification and gathered into the following species: Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, Enterococcus faecium, Leuconostoc fallax and Sporalactobacillus nakayamae subsp. nakayamae. Lactococcus lactis subsp. lactis strains was the species most frequently isolated during winemaking showing the highest resistance to SO2 and lysozyme

Malo-ethanolic fermentation in <I>Saccharomyces</I> and <I>Schizosaccharomyces</I>

NatuurwetenskappeMikrobiologiePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

Differential uptake of fumarate by Candida utilis and <I>Schizosaccharomyces pombe</I>.

NatuurwetenskappeMikrobiologiePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

Genetic Engineering of an Industrial Strain of <I>Saccharomyces cerevisiae </I>for L-Malic acid Degradation via an Efficient Malo- Ethanolic Pathway

NatuurwetenskappeMikrobiologiePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

Yeast killer toxins: from ecological significance to application

Killer toxins are proteins that are often glycosylated and bind to specific receptors on the surface of their target microorganism, which is then killed through a target-specific mode of action. The killer phenotype is widespread among yeast and about 100 yeast killer species have been described to date. The spectrum of action of the killer toxins they produce targets spoilage and pathogenic microorganisms. Thus, they have potential as natural antimicrobials in food and for biological control of plant pathogens, as well as therapeutic agents against animal and human infections. In spite of this wide range of possible applications, their exploitation on the industrial level is still in its infancy. Here, we initially briefly report on the biodiversity of killer toxins and the ecological significance of their production. Their actual and possible applications in the agro-food industry are discussed, together with recent advances in their heterologous production and the manipulation for development of peptide-based therapeutic agents

Use of fumaric acid to control pH and inhibit malolactic fermentation in wines

ABSTRACT Fumaric acid is an additive allowed by the Codex Alimentarius and under evaluation by the International Organisation of Vine and Wine (OIV) that can be used for wine acidification but also to inhibit malolactic fermentation (MLF). The use of 300–900 mg/L of fumaric acid can inhibit MLF in red wines decreasing pH by 0.2 units or more depending on the buffer capacity. When MLF was running with populations of either 7 or 8 log CFU/mL strain alpha (Oenococcus oeni) the application of 600 mg/L of fumaric acid stopped the process for more than 50 days and cells were undetected in specific media. In triangular tastings, fumaric acid was not detected at 300–600 mg/L (p < .05). In subsequent preference tests, some tasters perceived more acidity and body. Fumaric acid is a useful technological additive to improve wine microbiological stability and freshness, also allowing reduction of SO2 levels