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Zusammenfassung Die Weinrebe stellt ein natürliches Reservoir ansässiger mikrobieller Ressourcen dar, die in ein komplexes Mikroökosystem eingebettet ist. Ziel dieser Studie war herauszufinden, welche Keime sich im Blutungssaft befinden. Die Gewinnung des Blutungssaftes erfolgte mittels einer sauberen, mit Alkohol desinfizierten PET-Flasche. Nach erfolgter Anreicherung wurde die DNA-Extraktion mit anschließender NGS-Analyse mit der Zielregion V1V3 untersucht und die erhaltenen Sequenzen mit der NCBI-Datenbank abgeglichen. Die dominantesten Gattungen in den Rebstöcken waren Pseudomonas und Massilia, gefolgt von den Gattungen Zoogloea, Bacillus, Idonella, Sphingomonas und Paenibacillus. Zusätzlich konnte der hefeähnliche Mikroorganismus Aureobasidium pullulans bei zwei Rebstöcken bestimmt werden sowie wenige andere Bakteriengattungen, die vereinzelt auftreten. Die literarisch beschriebene hemmende Interaktion zwischen Pseudomonas und Aureobasidium konnte auch in unserer Studie bestätigt werden. Alle im Blutungssaft bestimmten Mikroorganismen haben generell einen pflanzenstärkenden Einfluss und stellen eine Basis für eine Besiedlung in gewebespezifische Pflanzenteile dar.

Zusammenfassung Weintrübung tritt häufig nach der Abfüllung aufgrund unzureichender Eiweißstabilisierung auf und wird oft als Qualitätsfehler von Kunden bezeichnet. Zur Vermeidung einer Weintrübung wird üblicherweise Bentonit verwendet, um bestimmte Proteinfraktionen zu entfernen. Proteasen stellen möglicherweise eine Alternative zu Bentonit dar, vor allem Aspergillopepsin. Ziel dieser Arbeit war heraus zu finden, ob es Vorteile für den Winzer durch den Einsatz einer sauren Protease, im Bereich Filtrationsleistung und Prophylaxe für Eiweißtrübungen gibt. Dafür wurden die Produkte Lallzyme P1 und Lallzyme P2 von der Firma Lallemand GmbH an der Sorte „Grüner Veltliner“ getestet. Die Ergebnisse zeigten, dass es große Unterschiede in der Filtrationsleistung gab. Die Enzymzugabe erhöht die Filtrierbarkeit der Weine wohingegen die Erhitzung der Probe diese wiederum senkte. Die beste Filtrierbarkeit zeigte die Probe, die sowohl mit dem Enzym Lallzyme P1 und P2 sowie mit Pectinasen versetzt und erhitzt wurde. Der Verblockungswert war am höchsten, wo keine Enzympräparate zugesetzt wurden. In der Darstellung der Proteine mittels SDS-PAGE konnten Unterschiede der Bandenintensitäten vor und nach der Enzymbehandlung festgestellt werden. Sensorisch konnten die erhitzten Weine eindeutig von den nicht erhitzten Proben differenziert werden.

Herbicides are increasingly applied in vineyards worldwide. However, not much is known on potential side effects on soil organisms or on the nutrition of grapevines (Vitis vinifera). In an experimental vineyard in Austria, we examined the impacts of three within-row herbicide treatments (active ingredients: flazasulfuron, glufosinate, glyphosate) and mechanical weeding on grapevine root mycorrhization; soil microorganisms; earthworms; and nutrient concentration in grapevine roots, leaves, xylem sap and grape juice. The three herbicides reduced grapevine root mycorrhization on average by 53% compared to mechanical weeding. Soil microorganisms (total colony-forming units, CFU) were significantly affected by herbicides with highest CFUs under glufosinate and lowest under glyphosate. Earthworms (surface casting activity, density, biomass, reproduction) or litter decomposition in soil were unaffected by herbicides. Herbicides altered nutrient composition in grapevine roots, leaves, grape juice and xylem sap that was collected 11 months after herbicide application. Xylem sap under herbicide treatments also contained on average 70% more bacteria than under mechanical weeding; however, due to high variability, this was not statistically significant. We conclude that interdisciplinary approaches should receive more attention when assessing ecological effects of herbicides in vineyard ecosystems. Electronic supplementary material The online version of this article (10.1007/s11356-018-2422-3) contains supplementary material, which is available to authorized users.

Glutathione (GSH, γ-L-Glutamyl-L-Cysteinyl Glycine) is a tripeptide of L-glutamate, L-cysteine and glycine. GSH in wine is derived from either grapes or yeast, during alcoholic fermentation. The GSH concentration in wine is very variable and depends on the environmental conditions as well as viticultural practices. During winemaking GSH has a significant role in oxidation prevention due to its unique redox and nucleophilic properties. Since GSH is very reactive it is highly important to prepare samples immediately and under inert conditions just prior to the determination of the GSH concentration. Therefore the aim of this research was to implement a method for the quantitative determination of GSH levels in grape juices (musts) made from different Austrian grape varieties and to investigate the influence of yeast on the GSH content in wine after aging. The results of this research have shown that monitoring with nitrogen gas, sulphur dioxide and freezing process at −25 ºC led to a good protective effect on the free glutathione amount in wine and grape samples. The GSH concentration in the samples was variable. Levels were ranging from non-detectable to up to 23.10 mg/l, and it showed that grape variety has no impact on GSH concentration in the must. Furthermore the results suggest that the choice of yeast has an impact on GSH content in wine even after 6 and 18 months of aging.

In a vineyard we examined the effects of broad-spectrum herbicides with three different active ingredients (glyphosate, glufosinate, flazasulfuron) on soil microorganisms. Mechanical weeding served as control treatment. Treatments were applied within grapevine rows and soil samples taken from there in 10–20 cm depth 77 days after application. Fungi were analyzed using classical sequencing technology and bacteria using next-generation sequencing. The number of colony-forming units (CFU) comprising bacteria, yeasts and molds was higher under flazasulfuron compared to all other treatments which had similar CFU levels. Abundance of the fungus Mucor was higher under flazasulfuron than glufosinate and mechanical weeding; Mucor was absent under glyphosate. Several other fungi taxa were exclusively found under a specific treatment. Up to 160 different bacteria species were found – some of them for the first time in vineyard soils. Total bacterial counts under herbicides were on average 260% higher than under mechanical weeding; however due to high variability this was not statistically significant. We suggest that herbicide-induced alterations of soil microorganisms could have knock-on effects on other parts of the grapevine system.

In this experiment, 27 different commercial yeasts were tested for their influence on the phenols of a rose wine. The phenols depend primarily on the vine variety, cultivation and cellar processing. This experiment sought to clarify how great the influence of the yeast on the phenols is. Blaufrankisch grapes with 20° KMW were matured in the cellar with 27 different commercial yeasts. The vinification was carried out in 34 l vessels. An HPLC Agilent Technology 1220 (RRLC) with a column of ZORBAX SB-C18 15 × 2.1 mm (1.8 μm) was used for the measurement. 5 μ l of the sample were injected directly. The column oven temperature was 40 °C. The transient was 0.5% formic acid (pH = 2.3) and a gradient of methanol (3%, 4%, 14%, 30% and 70%). The detection took place at 280 and 320 nm. It was shown that the effect of yeast on phenols is low. There was a great influence on the chemical substance tyrosol. This is a phenol that can be formed by the yeast itself. The values varied between 5.4 mg and 13.2 mg/l. The already described influence of the duration of fermentation on tyrosol formation could not be confirmed.

In this experiment RLU (relative light units) values of water of the filling stations of six wineries were examined before and after cleaning. For measurements of the ATP amounts an instrument from Kikkoman was used. This technique is very well suited for cleaning inspection. It shows quickly if the surface of filling station or water is clean or dirty. In this experiment rinse water of six wineries has been tested with LuciPac Pen (cotton swab for surface inspection) and LuciPac Pen-Aqua (special pens for water analysis). For most of the samples, the ATP measurements were made immediately after sample collection, with the remaining samples, the RLU values were taken only in the laboratory. The average ATP values of tap waters are approximately 20 RLU in Austria. This value agrees well with the water value of the Education and Research Center of Viticulture and Pomology in Klosterneuburg. The RLU amount was around 15 RLU. In wineries where well water was used as process water, dangerous germs were isolated. These bacteria were identified by Vitek 2 compact as soil bacteria of the family Pseudomonaceae.

In an experiment with Rosé wine, 27 different commercial yeasts were tested for their influence on the amino acid pattern of the wine. Amino acids are precursors for aromatic substances; therefore a large variation of the amino acid values in the wine was expected. Blaufränkisch grapes with 20° KMW were matured in the cellar with 27 different commercial yeasts. The fermentation was carried out in 34l vessels. The wines were measured for amino acids using an HP 1200 liquid chromatograph and HP-FLD1100 according to Umagat. The wines showed 13.5% alcohol and little residual sugar. The measurement results of the amino acids of the different wines showed large variations. For example, the amount of the amino acid alanine in wine varied from 17 to 138 mg. In particular, the wines of the yeast Pino Type showed the highest amounts of alanine in comparison to the other fermented wines.

The aim of the present study was to evaluate the autochthonous yeast population during spontaneous fermentations of grape musts in Austrian wine-producing areas. Investigation of genomic and genetic variations among wine yeasts was a first step towards a long-term goal of selecting strains with valuable enological properties typical for this geographical region. An approach, combining sequences of the D1/D2 domain of the 26S rRNA gene and random amplified polymorphic DNA fingerprinting, was used to characterize yeasts at the species level, whereas the differentiation of Saccharomyces strains was accomplished by amplified fragment length polymorphism fingerprinting. At the beginning of fermentation, representatives of nine genera were identified, with Hanseniaspora and Metschnikowia species characterized most frequently. Saccharomyces cerevisiae and Saccharomyces bayanus var. uvarum strains, which were identified throughout the entire fermentation process, showed a high level of genetic diversity. A number of S. cerevisiae strains were common at multiple wineries, but a wide range of strains with characteristic profiles were characterized at individual locations. This biodiversity survey represents a contribution to the investigation and preservation of genetic diversity of biotechnologically relevant yeasts in Austrian wine-making areas.

A genetic linkage map of grapevine was constructed with 92 progeny, which was derived from a cross of Welschriesling × Sirius using the pseudo-testcross strategy. Welschriesling is known for showing low magnesium uptake. The segregation pattern of this defect was compared with the segregation pattern of 251 molecular markers, 237 simple sequence repeat (SSR) and 14 random amplified polymorphic DNA (RAPD) marker. These markers were used to construct the parental genetic maps and could be arranged into 20 linkage groups. The maternal (Welschriesling) and the paternal (Sirius) maps were aligned in one consensus map. Mapmaker 3.0 software was used for the calculations of linkage groups. The genetic map rendered it possible to identify a QTL (quantitative trait loci) in linkage group 11. This loci can be associated with visual symptoms of Mg lack and the amount of Mg concentration in the leaves of the grape zone. The SSR markers VVS2 and VMC 6g1 showed the highest linkage to the core region of the Mg-QTL., José Luis Santiago is funded by a grant from Ministerio de Educacion y Ciencia of Spain.