IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Applications of FTIR microspectroscopy in oenology: shedding light on Saccharomyces cerevisiae cell wall composition and autolytic capacity

Applications of FTIR microspectroscopy in oenology: shedding light on Saccharomyces cerevisiae cell wall composition and autolytic capacity

Abstract

Many microbial starters for the alcoholic and malolactic fermentation processes are commercially available, indicated for diverse wine styles and quality goals. The screening protocols cover a wide range of oenologically relevant features, although some characteristics could also be studied using underexplored powerful techniques. In this study, we applied Fourier Transform Infrared (FTIR) microspectroscopy [1,2] to compare the cell wall biochemical composition and monitor the autolytic process in several wine strains of Saccharomyces cerevisiae. After cell death, autolysis trigger the release of mannoproteins and β-glucans, major components of yeast cell walls, influencing color, aroma, body, foaming properties, and stability of wine. Moreover, they can stimulate the metabolism of malolactic bacteria, while some fatty acids, also released during autolysis, act as inhibitors. Analysis of the cell wall structure was carried out both on cells grown in liquid medium and on cell walls previously separated from the other components. The autolytic capacity was assayed by sampling the cells at different times during induced autolysis in clarified and pasteurized must. From five to ten infrared spectra were acquired on each sample in the 4,000-700 cm-1 range in Attenuated Total Reflection on a 50×50 μm2 area. Spectra were analyzed after pretreatment through Hierarchical Cluster Analysis and Principal Component Analysis. Preliminary results were evaluated in relation to conventional spectrophotometric methods to quantify mannoproteins and β-glucans. The thickness of the cell walls was determined by means of scanning (SEM) and transmission electron microscopy (TEM). From the point of view of cell wall composition two groups of yeasts were distinguished by multivariate statistical analysis on the FTIR spectra since the strains EC1118, MY11 and PEDRO2000E showed higher absorption bands of mannoproteins and β-glucans. With conventional methods, the cell walls of the first two strains, alongside K1 and MY8, displayed a higher content of parietal polysaccharides, while the latter had the thickest wall among all the tested yeasts. The strains BM45 and D47 have a thinner surface structure. Regarding the autolytic process, again two different clusters were found distinguishing the behavior of the strains EC1118 and FRB with a similar timing of autolysis on one side from CH and Q20 on the other side. Furthermore, the latter strain presented a higher absorption in the spectral zone related to lipids, which can be correlated with a greater release of fatty acids in the medium. In conclusion, FTIR microspectroscopy proved to be an accurate and informative technique, suitable to highlight profound differences among S. cerevisiae strains as concerns both the content of parietal polysaccharides and the evolution of autolysis. Thus, this technique may become an option for the selection of starter cultures with properties fo great interest for the wine sector.

References

[1] Burattini, E., Cavagna, M., Dell’Anna, R., Malvezzi Campeggi, F., Monti, F., Rossi, F., & Torriani, S. (2008). A FTIR microspectroscopy study of autolysis in cells of the wine yeast Saccharomyces cerevisiae. Vibrational Spectroscopy, 47(2), 139-147. https://doi.org/10.1016/j.vibspec.2008.04.007.
[2] Cavagna, M., Dell’Anna, R., Monti, F., Rossi, F., & Torriani, S. (2010). Use of ATR-FTIR microspectroscopy to monitor autolysis of Saccharomyces cerevisiae cells in a base wine. Journal of Agricultural and Food Chemistry, 58(1), 39–45. https://doi.org/10.1021/jf902369s.

DOI:

Publication date: June 27, 2022

Issue: IVAS 2022

Type: Poster

Authors

Martelli Francesco1, Binati Renato Leal1, Monti Francesca2, Felis Giovanna1 and Torriani Sandra1

1Department of Biotechnology, University of Verona 
2Department of Computer Science, University of Verona

Contact the author

Keywords

FTIR microspectroscopy; starter cultures; Saccharomyces cerevisiae; autolysis; wine quality

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Assessment of climate change impacts on water needs and growing cycle on grapevine in three DOs of NE Spain

This study assessed the suitability of grapevine growing in three DOs (Empordà, Pla de Bages and Penedès) of Catalonia (NE Spain) over the 21st century. For this purpose, an estimation of water needs and agroclimatic and phenological indicators was made. Climate change impacts were estimated at 1 km pixel resolution using temperature and precipitation projections from several general circulation models (GCM) and two climate change scenarios: RCP 4.5 (stabilization scenario) and RCP 8.5 (worst-case scenario). Potential crop evapotranspiration (following FAO procedure) and a daily water balance considering soil water holding capacity were used to estimate actual evapotranspiration of vines and, finally, water needs. Dynamics would be similar in the three DOs studied although the magnitude of impact differs. Water needs would be 2 and 3 times greater (ranging from 0 to more than 1500 m3/ha) than current water needs at both climate change scenarios. Moreover, blooming date would advance from 3 to 6 weeks, harvest date from 1 to 2.5 months, resulting in growing cycles from 10 to 80 days shorter. It should also be noted that frost risk would decrease from 6 to 76%, the number of days with temperatures above 30ºC during ripening would rise from 48 to 500% and tropical nights (minimum temperature >20ºC) at ripening would increase from 28 to 150%, depending on the scenario and the DOs. The impacts of climate change in the three DOs could result in significant limitations for grapevine cultivation and wine production if adaptive strategies are not applied. This result could serve as a basis for the design of specific and particular adaptation strategies to improve and maintain vineyards in the DOs studied and could be extrapolated to similar DOs and regions.

Pruned vine biomass exclusion from a clay loam vineyard soil – examining the impact on physical/chemical properties

The wine industry worldwide faces increasing challenges to achieve sustainable levels of carbon emission mitigation. This project seeks to establish the feasibility of harvesting winter pruned vineyard biomass (PVB) for potential use in carbon footprint reduction, through its use as a renewable biofuel for energy production. In order to make this recommendation, technical issues such as the potential environmental impact, chemical composition and fuel suitability, and logistical challenges of harvesting biomass needs to be understood to compare with the results from similar studies. Of particular interest is the role PVB plays as a carbon source in vineyard soils and what effect annual removal might have on soil carbon sequestration. A preliminary trial was established in the Waite Campus vineyard (University of Adelaide) to test current management strategies. Vines are grown in a Eutrophic, Red Dermosol clay loam soil with well managed midrow swards. A comparison was undertaken of mid-row treatments in two 0.25 Ha blocks (Shiraz and Semillon), including annual cultivation for seed bed preparation, the deliberate exclusion of PVB (25 years) and incorporation of PVB (13 years) at an average of 3.4 and 5.5 Mg/Ha-1 for Shiraz and Semillon respectively. In both 0-10cm and 10-30cm soil core sample depths, combined soil carbon % measures in the desired range of 1.80 to 3.50, were not significantly different between treatments or cultivars and yielded an estimated 42 Mg/ha-1 of sequestered soil carbon. Other key physical and chemical measures were likewise not significantly different between treatments. Preliminary results suggest that in a temperate zone vineyard, managed such as the one used in this study, there is no long term negative impact on soil carbon sequestration through removing PVB. This implies that growers could confidently harvest PVB for use in several end fates including as a bio fuel.

Simulating climate change impact on viticultural systems in historical and emergent vineyards

Global climate change affects regional climates and hold implications for wine growing regions worldwide. Although winegrowers are constantly adapting to internal and external factors, it seems relevant to develop tools, which will allow them to better define actual and future agro-climatic potentials. Within this context, we develop a modelling approach, able to simulate the impact of environmental conditions and constraints on vine behaviour and to highlight potential adaptation strategies according to different climate change scenarios. Our modeling approach, named SEVE (Simulating Environmental impacts on Viticultural Ecosystems), provides a generic modeling framework for simulating grapevine growth and berry ripening under different conditions and constraints (slope, aspect, soil type, climate variability…) as well as production strategies and adaptation rules according to climate change scenarios. Each activity is represented by an autonomous agent able to react and adapt its reaction to the variability of environmental constraints. Using this model, we have recently analyzed the evolution of vineyards’ exposure to climatic risks (frost, pathogen risk, heat wave) and the adaptation strategies potentially implemented by the winegrowers. This approach, implemented for two climate change scenarios, has been initiated in France on traditional (Loire Valley) and emerging (Brittany) vineyards. The objective is to identify the time horizons of adaptations and new opportunities in these two regions. Carried out in collaboration with wine growers, this approach aims to better understand the variability of climate change impacts at local scale in the medium and long term.

Local adaptation tools to ensure the viticultural sustainability in a changing climate

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.19.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...

20-Year-Old data set: scion x rootstock x climate, relationships. Effects on phenology and sugar dynamics

Global warming is one of the biggest environmental, social, and economic threats. In the Douro Valley, change to the climate are expected in the coming years, namely an increase in average temperature and a decrease in annual precipitation. Since vine cultivation is extremely vulnerable and influenced by the climate, these changes are likely to have negative effects on the production and quality of wine.
Adaptation is a major challenge facing the viticulture sector where the choice of plant material plays an important role, particularly the rootstock as it is a driver for adaptation with a wide range of effects, the most important being phylloxera, nematode and salt, tolerance to drought and a complex set of interactions in the grafted plant.
In an experimental vineyard, established in the Douro Region in 1997, with four randomized blocs, with five varieties, Touriga Nacional, Tinta Barroca, Touriga Franca and Tinta Roriz, grafted in four rootstocks, Rupestris du Lot, R110, 196-17C, R99 and 1103P, data was collected consecutively over 20 years (2001-2020). Phenological observations were made two to three times a week, following established criteria, to determine the average dates of budbreak, flowering and veraison. During maturation, weekly berry samples were taken to study the dynamics of sugar accumulation, amongst other parameters. Climate data was collected from a weather station located near the vineyard parcel, with data classified through several climatic indices.
The results achieved show a very low coefficient of variations in the average date of the phenophases and an important contribution from the rootstock in the dynamic of the phenology, allowing a delay in the cycle of up to10-12 days for the different combinations. The Principal Component Analysis performed, evaluating trends in the physical-chemical parameters, highlighted the effect of the climate and rootstock on fruit quality by grape varieties.