The role of nitrogen uptake on the competition ability of three vineyard Saccharomyces cerevisiae strains

Three vineyard strains of Saccharomyces cerevisiae, P301.4, P304.4 and P254.12, were assayed in comparison with a commercial industrial strain, QA23. The aim was to understand if nitrogen availability could influence strain competition ability during must fermentation. Pairwise-strain fermentations and co-fermentations with the simultaneous presence of the four strains were performed in synthetic musts at two nitrogen levels: control nitrogen condition (CNC) that assured the suitable assimilable nitrogen amount required by the yeast strains to complete the fermentation and low nitrogen condition (LNC) where nitrogen is present at very low level. Results suggested a strong involvement of nitrogen availability, as the frequency in must of the vineyard strains, respect to QA23, in LNC was always higher than that found in CNC. Moreover, in CNC only strain P304.4 reached the same strain frequency as QA23. P304.4 competition ability increased during the fermentation, indicating better performance when nitrogen availability was dropping down. P301.4 was the only strain sensitive to QA23 killer toxin. In CNC, when it was co-inoculated with the industrial strain QA23, P301.4 was never detected. In LNC, P301.4 after 12 h accounted for 10% of the total population. This percentage increased after 48 h (20%). Single-strain fermentations were also run in both conditions and the nitrogen metabolism further analyzed. Fermentation kinetics, ammonium and amino-acid consumptions and the expression of genes under nitrogen catabolite repression evidenced that vineyard yeasts, and particularly strain P304.4, had higher nitrogen assimilation rate than the commercial control. In conclusion, the high nitrogen assimilation rate seems to be an additional strategy that allowed vineyard yeasts successful competition during the growth in grape musts

Experimental achievement of the entanglement assisted capacity for the depolarizing channel

We experimentally demonstrate the achievement of the entanglement assisted capacity for classical information transmission over a depolarizing channel. The implementation is based on the generation and local manipulation of 2-qubit Bell states, which are finally measured at the receiver by a complete Bell state analysis. The depolarizing channel is realized by introducing quantum noise in a controlled way on one of the two qubits. This work demonstrates the achievement of the maximum allowed amount of information that can be shared in the presence of noise and the highest reported value in the noiseless case.Comment: 4 pages, 3 figure

Biocontrol Ability and Action Mechanism of Starmerella bacillaris (Synonym Candida zemplinina) Isolated from Wine Musts against Gray Mold Disease Agent Botrytis cinerea on Grape and Their Effects on Alcoholic Fermentation

Gray mold is one of the most important diseases of grapevine in temperate climates. This plant pathogen affects plant growth and reduces wine quality. The use of yeasts as biocontrol agents to apply in the vineyard have been investigated in recent years as an alternative to agrochemicals. In this work, fermenting musts obtained from overripe grape berries, therefore more susceptible to infection by fungal pathogens such as Botrytis cinerea, were considered for the selection of yeasts carrying antifungal activity. Thirty-six isolates were identified as Starmerella bacillaris, a species recently proven to be of enological interest. Among them 14 different strains were studied and antifungal activity against B. cinerea was demonstrated, for the first time, to be present in S. bacillaris species. The production of volatile organic compounds (VOCs), tested in vitro, was found to be the main responsible of S. bacillaris antifungal effects. All the strains were able to reduce B. cinerea decay on wounded grape berries artificially inoculated with gray mold. The colonization level of wound was very high reaching, after 5 days, a concentration of 10(6) cells per ml of grape juice obtained after berry crushing. At this cell concentration S. bacillaris strains were used to ferment synthetic and natural musts. The sequential yeast inoculation, performed by adding S. cerevisiae 48 h after S. bacillaris, was needed to complete sugar consumption and determined a significant increase in glicerol content and a reduction of ethanol and acetic acid concentrations. The high wound colonization ability, found in this work, together with the propensity to colonize grape berry and the interesting enological traits possessed by the selected S. bacillaris strains allow the use of this yeast as biocontrol agent on vine and grape berries with possible positive effects on must fermentation, although the presence of S. cerevisiae is needed to complete the fermentation process. This work introduces new possibilities in wine yeast selection programs in order to identify innovative wine yeasts that are simultaneously antifungal agents in vineyards and alternative wine starters for grape must fermentation and open new perspective to a more integrated strategy for increasing wine quality

Characteristics of Compost Obtained from Winemaking Byproducts

A model procedure for the sustainable management of plant biomass related to wine production, namely vine branches from agricultural practices in the vineyard and marcs remaining after grapes crushing, was devised. An artificial humification process was set up that could respond to the needs of environmental sustainability and could be a safe way to be reintroduce in the vineyard part of the organic matter previously exported, thus contributing to recover or maintain vineyard soil fertility. Two different strategies for composting were tested, namely a static pile, made by branches and marcs, and a pile that was fed twice a year alternatively with vine branches and grape marcs. The experimentation lasted 710 days, during which environmental parameters, i.e. temperature and rainfalls were monitored. Growth dynamics of the principal functional groups of microorganism were followed. A characterization of the composted material was obtained by measuring several parameters among which, pH, carbon, nitrogen, sulfur and heavy metals content. The characteristics of the produced compost fulfill the requirements prescribed by the Italian legislation regarding the use of compost as soil amendment. Germination tests demonstrated the absence of phytotoxicity and conversely evidenced a stimulating activity towards root development

A mathematical model to infer underground thermal characteristics for the design of borehole heat exchangers

Geothermal exchangers are exploited as tools for the indirect analysis of the thermal properties of the underground material. Two simple inverse problems based on different heat transfer models are proposed: the first one is based on the cylindrical model of heat transfer and yields the thermal parameters of the borehole, the second one is based on a forced convective model and yields the soil thermal profile. We test our approach on sets of data collected by direct numerical simulation and from a real experiment

The addition of wine yeast Starmerella bacillaris to grape skin surface influences must fermentation and glycerol production

Starmerella bacillaris is a non-Saccharomyces yeast recently proposed for grape fermentation in association with Saccharomyces cerevisiae. Due to its high glycerol and moderate volatile acidity production this yeast can contribute to improving wine quality. Some strains have been demonstrated to exhibit antifungal activity against grey mould on grape, which is caused by Botrytis cinerea. The simultaneous presence of these traits in S. bacillaris is of great interest. Indeed, this yeast can be potentially used as a biocontrol agent in vineyards. Research on the ability of S. bacillaris to survive or, even to grow on the surface of grapes is a starting point in the evaluatation of its potential use in vineyards. The preliminary results of our study showed that when applied to the grape surface under laboratory condictions, inoculum sized S. bacillaris with antifungal activity developed and lasted for at least 6 days in high concentrations. In addition, it positively influenced the fermentation process by producing high concentrations of glycerol (average value 4.89 ± 0.47 g/L). Interestingly, a positive effect on wine quality was also observed when the inoculum size was 10 times higher or lower than the reference concentration. When sprayed on the vines in the vineyard and present on the grape skin surface after harvest, S. bacillaris cells can start alcoholic fermentation

Prevalence of Viral Hepatitis in Unselected, Consecutively Enrolled Patients Hospitalised for SARS-CoV-2

Diagnosing people living with chronic viral hepatitis is challenging due to the absence of symptoms as long as liver decompensated cirrhosis come out. The aim of this retrospective study was to evaluate the prevalence of HBV and/or HCV infections in a non-selected population, hospitalised for SARS-CoV-2 infection in a tertiary care hospital in Northern Italy. During the study period 1,429 patients were admitted to hospital for SARS-CoV-2 infection, serologic tests for HBV and/or HCV were available for 382 (27%) patients and 3 were excluded due to their previous known serologic status. Among 379 patients, 235 (62%) were male, median age was 70 years (range 21-103), 360 (95%) were Caucasian. Among them, 372/379 (98%) were screened for HBsAg, 320/379 (84%) for HBcAb. HBsAg was positive in 2/372 (0.5%, 95% CI 0.0006-0.02) patients (only in one HBV-DNA was performed that was negative), while HBcAb was found positive in 55/320 (17%, 95% CI 0.13-0.22). Among 370/379 (98%) patients screened for HCV, 11/370 (3%, 95% CI 0.02-0.05) had positive HCV-Ab. Five out of 11 (45%) were tested for HCV-RNA that resulted positive in two patients (0.5%, 95% CI 0.0006-0.02). Considering this data, even though the screening was performed in only 27% of study population, a tailored screening in people with known risk factors for hepatitis might be preferable to universal screening in low prevalence areas. Also a prompt diagnostic workout should begin in case of clinical or laboratory suspicion of hepatitis and in those starting immunosuppressive treatments

Draft genome sequence of the yeast Starmerella bacillaris (syn., Candida zemplinina) FRI751 isolated from fermenting must of dried Raboso grapes

Starmerella bacillaris is an ascomycetous yeast commonly present in enological environments. Here, we report the first draft genome sequence of S.\ua0bacillaris FRI751, which will facilitate the study of the characteristics of this interesting enological yeast

Polarization preserving ultra fast optical shutter for quantum information processing

We present the realization of a ultra fast shutter for optical fields, which allows to preserve a generic polarization state, based on a self-stabilized interferometer. It exhibits high (or low) transmittivity when turned on (or inactive), while the fidelity of the polarization state is high. The shutter is realized through two beam displacing prisms and a longitudinal Pockels cell. This can represent a useful tool for controlling light-atom interfaces in quantum information processing.Comment: 4 pages, 6 figure

Whole-genome sequence of Starmerella bacillaris PAS13, a nonconventional enological yeast with antifungal activity

Starmerella bacillaris is a fermentative yeast commonly found in vineyards. Here, we present the draft genome sequence of S. bacillaris PAS13, a nonconventional enological yeast with a potential role as a biocontrol agent. This gene sequence will provide insights into the genetic basis of yeast activity against gray mold disease (Botrytis cinerea)