Grapevine Pinot gris virus (GPGV) is considered to be a causal agent of Grapevine Leaf Mottling and Deformation (GLMD) disease that has been reported worldwide through the grapevine-growing regions. Seven grapevines that were collected from a vineyard in the Czech Republic were tested for the presence of GPGV in leaf and phloem tissues. Each of the seven grapevines was infected by GPGV, from which sic symptoms were mostly shown without a typical mottling. The phylogeny based on RNA-dependent RNA polymerase and movement/coat protein sequences indicated the same origin of the GPGV isolates. The GPGV titer was the highest in the grapevines with the highest GLMD-like symptoms; however, some of the grapevines with milder GLMD-like symptoms had a lower GPGV titer than the asymptomatic grapevine. Soil analysis showed uneven boron content in the direct vicinity of the grapevines, while the boron content in the grapevines was more, even showing no boron deficiency. The quantitative analysis of selected gene expressions associated with boron efflux and transport only partially explained the boron content in the soil and grapevines and only in the grapevines growing in soils with the highest or lowest boron contents. The VvBor2 and VvNIP5 genes had a higher expression and VvNIP6 had a lower expression in the grapevine growing in the soil with the lowest boron content, while a low expression of VvBor1 and VvBor2 was observed in the grapevine that was grown in the soil with the highest boron content.

This work aimed to study the properties of acetic fermentation bacteria during the acetic fermentation of wine. Attention was focused on the ability of the bacteria to metabolize selected organic substances and their suitability for wine vinegar production. For the production of wine vinegar, white wine of the variety Veltliner Green was used. Three variants were established for this experiment. The first variant was fermented with Gluconobacter oxydans, the second with Acetobacter aceti, and the third variant of vinegar production was carried out by spontaneous fermentation. During the vinegar fermentation, samples were taken at regular 24-hour intervals and subsequently analyzed. The alcohol, acetic, malic, and tartaric acid contents were monitored. The results showed that all variants showed a strong acetic and malic acid increase. Bacteria Acetobacter aceti produced the most acetic acid within nine days (25 g.L-1). This bacterium also produced the most lactic acid (18 g.L-1). Tartaric acid was also produced in all three variants, but not to the same extent as the previous two organic acids. Acetobacter aceti was found to metabolize ethanol more rapidly than Gluconobacter oxydans.

The presented work aimed to study the inhibition using nanoparticles produced by the green synthesis in selected acetic acid and lactic acid bacteria, which are related to viticulture. The degree of ability to eliminate silver particles produced by green syntheses was determined using the plate method on Petri dishes. This is done using two different approaches - the method of direct application of the solution to the surface of the inoculated medium (determination of inhibition zones) and the method of application using nanoparticles to the inoculated medium. Gluconobacter oxydans (CCM 3618) and Acetobacter aceti (CCM 3620T) were studied from acet acetic bacteria. The lactic acid bacteria were Lactobacillus brevis (CCM 1815) and Pediococcus damnosus (CCM 2465). The application of silver nanoparticles was always in concentrations of 0, 0.0625, 0.125, 0.25, 0.5, and 1 g.L-1. All applied concentrations of silver nanoparticles showed an inhibitory effect on the monitored microorganisms. Silver particles could be used in wine technology for their antibacterial effects, mainly to inhibit microorganisms during vinification, as a substitute for sulfur dioxide.