No abstract

Starmerella bacillaris (synonym Candida zemplinina) is an important non-Saccharomyces yeast in winemaking with valuable oenological properties, accompanying Saccharomyces species in sweet wine fermentation, and has also been suggested for application as combined starter culture in dry or sweet wines. In this study, the major metabolites and nitrogen utilization of these yeasts are evaluated in the musts with high or extremely high sugar concentration. The change in the metabolic footprint of Saccharomyces cerevisiae, Saccharomyces uvarum and Starmerella bacillaris strains was compared when they were present as pure cultures in chemically defined grape juice medium with 220 and 320 g/L of sugar, to represent a fully matured and an overripe grape. Surprisingly, the extreme sugar concentration did not result in a considerable change in the rate of sugar consumption; only a shift of the sugar consumption curves could be noticed for all species, especially for Starmerella bacillaris. At the extreme sugar concentration, Starmerella bacillaris showed excellent glycerol production, moderate nitrogen demand together with a noticeable proline utilisation. The change in the overall metabolite pattern of Starmerella bacillaris allowed clear discrimination from the change of the Saccharomyces species. In this experiment, the adequacy of this non-Saccharomyces yeast for co-fermentation in juices with high sugar concentration is highlighted. Moreover, the results suggest that Starmerella bacillaris has a more active adaptation mechanism to extremely high sugar concentration.

During the ageing in barrels, the contact with the fi ne lees triggers several processes in wine. Lees has a reductive effect by absorbing dissolved oxygen and reducing the amount, which will remain in the wine. At present, minimizing the addition of sulphur dioxide is the trend in all viticultural areas. In this study, the effect of various sulphur dioxide levels was monitored in presence of the lees to determine which dose is appropriate to provide the protection of susceptible white wine against oxidation.Without SO 2 protection, the rH and redox potential changed slightly, so the level of dissolved oxygen seemed to be controlled during the ageing period by the lees, though the antioxidant effect of lees in itself was not appropriate to protect the polyphenol content from chemical oxidation, which led to considerable browning. With the addition of a lower amount of SO 2 -40 mg l -1 , the lees is already able to protect the white wine samples in all aspects. Keywords: sur lie, fi ne lees, reducing agent, polyphenolic compoundsThe sur lie method is a special wine making technology, where the contact between the new wine and the fi ne lees can be taken advantage of. It has a special momentum, namely the battonage, when the wine is stirred periodically in the barrels. This technology originates from France, but nowadays wine makers -in all viticultural areas -use it to widen the white wine assortment. The contact with the fi ne lees plays an important role in traditional champagne production, too (FIA et al., 2016). From the practical point of view, the robust/full bodied wine, which is properly rich in alcohol and acids, is fi t for ageing on lees in oak barrels.The composition of fi ne lees is varying. It contains mainly yeast cells, and in much lower amount, tartaric acid and other organic and inorganic matter. The autolysis is known as a slow process that occurs during the wine ageing period (between 12 to 18 months). So the intracellular compounds, enzymes, plasma membrane, etc., are released just approximately after one year (LAVIGNE et al., 2007;PÉREZ-SERRADILLA & LUQUE DE CASTRO, 2008).It was shown that the resuspension of the lees by stirring (battonage) during the aging period signifi cantly increased the macromolecular extract of the wine (especially mannoproteins, proteins) beside saturated fatty acids and glutathione. The yeast strain, the turbidity of juice during the fermentation, the contact time and temperature also have effects on the migration of the polysaccharides (PÉREZ-SERRADILLA & LUQUE DE CASTRO, 2008).

The transmission of Severe Acute Respiratory Syndrome Coronavirus-2 in a community can be monitored by a wastewater-based epidemiological approach due to fecal shedding. Although sewage surveillance has gained a considerable amount of attention over the last 16 months, an indirect issue within the topic is whether traditional wastewater treatment technologies are sufficiently efficient to eliminate the genetic material of SARS-CoV-2. Samples were taken from the Wastewater Treatment Plant in Nagykanizsa before the virus was concentrated, nucleic acid extracted and SARS-CoV-2 detected by RT-qPCR (Quantitative reverse transcription PCR). The influent and primary treated samples tested positive, while after the secondary treatment, all the results were negative. Consequently, the activated sludge process proved to be efficient in terms of the removal of SARS-CoV-2.

In the last few years food compounds which have a physiological effect (especially wine compounds) came to the front, therefore biogenic animes have gained on importance. In our experiment we determined - for oenological conditions important - histamine, tyramine and serotonin content with HPLC technique. Biogenic amines are produced from amino-acids (precursors) during the decarboxylation procedure. Commercial fertilizers and combinations were independent factors, and biogenic amine concentrations were observed as dependent factors (the Cserszegi ffiszeres samples, vintage 2015, were homogenous form in every aspects except the fertilizer usage under alcoholic fermentation=AF). After AF - thus after various fertilizer additions - considerable changes were shown in the amount of the investigated three compounds, although we could not find an obvious pattern. Histamine and tyramine were far away from the toxic limit, serotonin presence was slightly higher than in the earlier results, however serotonin is not a poisonous compound (positive evaluation), hence the ascent was not a problem.