1. Lactic acid bacteria and Brettanomyces bruxellensis in Teran wine : impact on biogenic amines and volatile phenolsTatjana Radovanović Vukajlović, Shanique Walker, Julija Šupljika, Mitja Martelanc, Jan Reščič, Melita Sternad Lemut, Branka Mozetič Vodopivec, Dejan Bavčar, Klemen Lisjak, Lorena Butinar, 2025, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Yeasts and lactic acid bacteria (LAB) are the main microorganisms involved in wine production, responsible for alcoholic fermentation and malolactic fermentation (MLF), respectively. During MLF, LAB convert L-malic acid into L-lactic acid, which primarily leads to biological deacidification but also results in changes to the wine’s aroma and microbiological stability. While LAB generally improve wine quality, certain strains can cause spoilage and are linked to the production of biogenic amines (BAs)—nitrogenous compounds such as histamine, tyramine, and putrescine. At elevated levels, BAs may pose health risks, especially for sensitive individuals, potentially causing headaches, hypertension, and digestive issues. Likewise, the yeast Dekkera/ Brettanomyces bruxellensis is considered a spoilage organism due to its ability to produce volatile phenolic compounds (e.g., 4-ethylguaiacol and 4-ethylphenol), which impart off-flavors resembling bandages, sweat, and smoke. As part of the AGROTUR+ project, we monitored LAB and B. bruxellensis populations, as well as BA and volatile phenol content, during MLF in Teran - a protected wine made from Refošk grapes in the Karst wine-producing region. The goal was to assess the presence of spoilage-related compounds and support improvements in microbiological quality of this traditional wine. A total of 26 Teran wine samples from the 2024 vintage were analyzed. Volatile phenols were analyzed using HS-SPME-GC-MS, and BAs were determined via HPLC–UV following sample derivatization. Basic quality physicochemical parameters were determined using standard methods. LAB and B. bruxellensis populations were estimated through conventional microbiological techniques and flow cytometry. Regarding BA content, histamine was the most abundant (average 21.9 mg/L), followed by putrescine (3.7 mg/L) and cadaverine (1.6 mg/L). No correlation was observed between total LAB counts and BA levels, indicating the need for further analysis of LAB strain composition. For volatile phenols, 4-ethylphenol was found at concentrations below its sensory threshold (600 µg/L), while 4-ethylguaiacol exceeded its threshold (110 µg/L) in three samples. In these, B. bruxellensis was detected using the CyFlow™ BrettCount flow cytometry kit (Sysmex Partec), though no colonies were observed on selective Dekkera/Brettanomyces differential medium (DBDM). Flow cytometry proved to be a rapid and specific method for detecting spoilage yeasts like B. bruxellensis, with strong potential for early intervention and spoilage prevention in winemaking.
Ključne besede: lactic acid bacteria, biogenic amines, Teran
Objavljeno v RUNG: 17.06.2025; Ogledov: 105; Prenosov: 0
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3. Predstavitev rezultatov anketiranja vinarjev na festivalu Okusi Vipavske : predavanje na Vino in podnebje: Kdaj trgati v času sprememb?, Vipava, 3. jun. 2025Jan Reščič, 2025, prispevek na konferenci brez natisa Opis: Predstavljeni so preliminarni rezultati ankete, ki smo jo izvedli med vinarji v okviru festivala Okusi Vipavske 2025. Anketa je bila vezana na nekatere trajnostne ukrepe (razlistanje, nalaganje sladkorjev, upravljanje z vodo v vinogradih ter biotska raznovrstnost) za prilagajanje vinogradov na podnebne spremembe. Zanimala nas je informacija oziroma mnenja vinarjev, ali/in kako te ukrepe izvajajo v njihovih vinogradih. Rezultati so pokazali, da se vinarji dobro zavedajo učinkov podnebnih sprememb, ter da nekatere ukrepe (kot je npr. razlistanje, nalaganje sladkorjev) tudi poznajo in izvajajo. Prav tako so vinarji izrazili željo, da bi se o predstavljenih ukrepih še dodatno izobraževali.
Ključne besede: vinogradništvo, podnebne spremembe, trajnost, naravni pristopi, anketa, vinarji
Objavljeno v RUNG: 05.06.2025; Ogledov: 516; Prenosov: 0
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4. Water stress impacts on grapevine functioning and possible adaptation measures : lecture at the winter school, organized in the frame of an Erasmus+ Blended Intensive Programme (BIP), University of Udine, 4. 2. 2025Jan Reščič, 2025, predavanje na tuji univerzi Opis: Europe is the continent which is heating up with the highest speed. In viticulture every year we face extreme weather events, from higher rainfalls to droguth periods. It is therefore important to know what water stress (lack of water) is and how it impacts the physiology and metabolism of grapevine plants. In addition in the lecture, main measures on how to adapt the viticulture to water stress, are presented and discussed.
Ključne besede: podnebne spremembe, vodni stres, vinska trta, prilagajanje
Objavljeno v RUNG: 14.02.2025; Ogledov: 1207; Prenosov: 0
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5. Lahko v Sloveniji ostanemo brez določenih vinskih sort?2024, intervju Opis: Podnebne spremembe slovenskim vinarjem povzročajo velike preglavice. Ob toplih pomladih trte vzbrstijo vse bolj zgodaj, na mlade poganjke pa nato preži pozeba. Če ji vinogradi uidejo, je nato pred njimi burno poletje s sušo in vročino na eni ter neurji in točo na drugi strani. Kako vse skupaj vpliva na kakovost vina in kakšni so obeti za slovenske vinarje? Odgovarjata Guillaume Antalick in Jan Reščič s fakultete za vinogradništvo in vinarstvo Univerze v Novi Gorici.
Ključne besede: podnebne spremembe, vinogradništvo, vinska trta, prilagajanje
Objavljeno v RUNG: 13.11.2024; Ogledov: 1450; Prenosov: 2
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7. Drought and temperature interaction on leaf hydraulic traits in grapevineElena Farolfi, Jan Reščič, Jacobs Spencer Harrison, Astrid Forneck, Jose Carlos Herrera, 2022, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Global warming and increased frequency and/or severity of drought events are among the most
threatening consequences of climate change for agricultural crops. Understanding the mechanisms of
plant responses to both stressors is pivotal to successfully implement management strategies. Here
we explored the effect of temperature on the development of grapevine leaves with particular focus
on hydraulic traits under well-watered and water deficit conditions. We grew grafted grapevine (Vitis
vinifera L. cv. Pinot noir) in two different greenhouse chambers (20/15°C vs 25/20°C day/night) and
monitored their gas exchange, leaf size, stomatal density, chlorophyll fluorescence, pressure-volume
(PV) curves, osmotic potential and petiole xylem anatomy. PV curves provided clear evidence that
both, temperature and water availability, strongly affected the turgor loss point (TLP) as well as the
connected physiological traits. Leaves developing at higher temperature exhibited a more conservative
behaviour characterised by a lower gs max and a tighter stomatal closure in response to drought. The
study further discusses the results considering the coordination of traits changing in tandem and
implications in the face of climate change.
Key message: The ambient temperature at which leaves develop impacts on its hydraulic traits and
therefore on their successive response to drought
Ključne besede: drought, temperature, grapevine, xylem
Objavljeno v RUNG: 05.07.2024; Ogledov: 1572; Prenosov: 5
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8. Pregled pridelave grozdja in vina žlahtne vinske trte (Vitis vinifera l.) 'pinela' in 'zelen' v Vipavski dolini : diplomsko deloVeronika Kos, 2024, diplomsko delo Opis: V tej diplomski nalogi smo s pomočjo anketiranja pridelovalcev pregledali, na kakšen način se prideluje grozdje in vino pri sortah Vitis Vinifera L. 'Zelen' in 'Pinela' v zgornji Vipavski dolini. Pomembno je, da razumemo, da ti dve sorti rasteta na flišni podlagi in pod submediteranskim podnebjem. Ampelografski opis nam razloži, kako ti dve sorti ločimo od ostalih. V nadaljevanju smo s pomočjo anketiranja pridelovalcev teh dveh sort dobili vpogled v način pridelave grozdja, tipe rezi, uporabo ukrepa razlistanja in ugotovili, da je večina vinogradov obrnjenih na vzhod ali zahod. V povprečju dosega mošt/grozdje sorte 'Zelen' višji pH kot sorta 'Pinela', kar tudi vzporedno pojasni, da ima 'Zelen' nižje kisline. Količina pridelanega grozdja se vsako leto povečuje, v grafu lahko vidimo enakomerno rast pri sorti 'Zelen', nekoliko manj enakomerno pa pri sorti 'Pinela', kar je posledica zunanjih dejavnikov. Iz ankete je razvidno, da se tako pri maceraciji kot tudi pri skladiščenju največkrat uporabljajo posode iz nerjavečega jekla, nekateri pa uporabljajo tudi lesene sode.
Ključne besede: diplomske naloge, pinela, zelen, Vipavska dolina, pridelava, vino, grozdje
Objavljeno v RUNG: 21.03.2024; Ogledov: 3516; Prenosov: 43
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9. Sodobno vinogradništvo in vinarstvo : novosti in izziviErika Jež, Jan Reščič, 2023, samostojni strokovni sestavek ali poglavje v monografski publikaciji Opis: Prispevek o izzivih in novostih današnjega vinogradništva. Med izzivi so predstavljene podnebne spremembe, evropska politika, zaraščanje površin, tržne strategije in obnašanje potrošnikov ter izobraževanje mladih kmetov. Med novostmi pa je predstavljena sodobna tehnologija in digitalizacija, regenerativno vinogradništvo, krožno gospodarstvo in avtentičnost.
Ključne besede: vinogradništvo, vinarstvo, izzivi, novosti, Slap
Objavljeno v RUNG: 07.02.2024; Ogledov: 3143; Prenosov: 0
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10. Time vs drought : leaf age rather than drought drives osmotic adjustment in V. vinifera cv. Pinot NoirElena Farolfi, Jan Reščič, 2023, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Global warming and increased frequency and/or severity of drought events are among the most threatening consequences of climate change for agricultural crops. In response to drought, grapevine (as many other plants) exhibits osmotic adjustment through active accumulation of osmolytes which in turn shift the leaf turgor loss point (TLP) to more negative values, allowing to maintain stomata opened at lower water potentials1. We investigated the capacity of Pinot noir leaves to modulate their osmotic potential as a function of: (i) time (seasonal osmoregulation), (ii) growing temperatures, and (iii) drought events, to enhance comprehension of the resilience of grapevines in drought conditions. We performed trails under semi-controlled field conditions, and in two different greenhouse chambers (20/15 °C vs 25/20 °C day/night). For two consecutive vegetative seasons, grafted potted grapevines (Pinot noir/SO4) were subjected to two different water regimes for at least 30 days: well-watered (WW) and water deficit (WD). Via pressure-volume (PV) curves and osmometer measurements we derived the leaf osmotic adjustment capability and TLP, while monitoring the plant gas exchange and water potential. Surprisingly, lower water potentials in WD vines throughout the season and in all situations (field and greenhouse) did not trigger osmoregulation, changes in TLP nor a modification of the modulus of elasticity. PV curves provided clear evidence that both temperature and water availability do not stimulate active osmotic adjustment in Vitis vinifera cv. Pinot Noir. Conversely, there is a clear impact of seasonal osmoregulation throughout the growing season2, decreasing the osmotic potential at full turgor by an average of 0.46 MPa in 90 days. Lack of osmotic adjustment in response to drought observed in this cultivar suggests Vitis genotypes have a broad spectrum of responses to drought and the strategy adopted to cope with it is highly dependent on the cultivar under analysis.
Ključne besede: grapevine, drought, osmotic adjustment, osmoregulation, turgor loss point
Objavljeno v RUNG: 21.11.2023; Ogledov: 3031; Prenosov: 3
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