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Microscopic observation of (a) D. hansenii 5-1-6, (b) S. cerevisiae PDA W 10, (c) T. delbrueckii 3-16-1, (d) Z. bailii 24-1-25 grown on sodium acetate agar. Zoomed parts: (a) cells with conjugation tubes, (b), (c), and (d) spores. Magnification 40×; scale 20 μm (small bar for global views; large bar for detailed views).
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Wine reflects the specificity of a terroir, including the native microbiota. In contrast to the use of Saccharomyces cerevisiae commercial starters, a way to maintain wines’ microbial terroir identities, guaranteeing at the same time the predictability and reproducibility of the wines, is the selection of autochthonous Saccharomyces and non-Sacchar...
Citations
... Different strains of yeast contribute to the flavor, aroma, and alcohol content of the final beverages. In addition to Saccharomyces cerevisiae, other yeast species such as Saccharomyces pastorianus and Brettanomyces bruxellensis are also involved in specific types of alcoholic fermentations [26,27]. ...
Fungi play a crucial role in food production, processing, and preservation, yet their effects on food safety and quality are diverse and complex. This review aims to comprehensively analyze the multifaceted involvement of fungi in the food industry, emphasizing both their beneficial and harmful impacts. The literature review was conducted through an extensive search of databases including Pub-Med, Scopus, Web of Science, and Google Scholar, using keywords such as "fungi in food" and "mycotoxins" in order to meet the objective of the study. It was observed that fungi have multifaceted role in food sector contributing to various aspects in the field of dairy industry, bakery industry, post-harvest technology of fruits and vegetables, mycoprotein production, mycotoxin production and food spoilage. Various types of fungal cultures are incorporated into the food industry to enhance shelf stability, nutritional content and ensure food safety. Examining both the health benefits and risks associated with fungal consumption, this review underscores the need for proper management and understanding of fungi to ensure food safety, quality and innovation in the food industry.
... Commercial S. cerevisiae strains assure fermentation completion and enhance the standardization and reproducibility of the final product. However, they often lack some unique characteristics linked to biodiversity parameters, and therefore the final wines may lack complexity and typicity (Comitini et al., 2017;Parapouli et al., 2020;Sidari et al., 2021;Christofi et al., 2022). ...
... Therefore, time efficient methods are crucial when isolating new strains. The process of screening and selecting wine yeasts typically involves several sequential steps (Sidari et al., 2021;Pulcini et al., 2022). However, it is necessary to initially exclude certain isolates when dealing with a vast collection of yeast isolates during the selection process. ...
... Frontiers in Microbiology 11 frontiersin.org selection and rejection may not always be feasible especially when no ideal combination of technological properties is discernible, as suggested in previous studies (Mestre Furlani et al., 2017;Sidari et al., 2021). Yeast selection is a very interesting field not only in wine microbiology, but also in food microbiology. ...
The selection of native yeast for alcoholic fermentation in wine focuses on ensuring the success of the process and promoting the quality of the final product. The purpose of this study was firstly to create a large collection of new yeast isolates and categorize them based on their oenological potential. Additionally, the geographical distribution of the most dominant species, Saccharomyces cerevisiae, was further explored. Towards this direction, fourteen spontaneously fermented wines from different regions of Greece were collected for yeast typing. The yeast isolates were subjected in molecular analyses and identification at species level. RAPD (Random Amplified Polymorphic DNA) genomic fingerprinting with the oligo-nucleotide primer M13 was used, combined with Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) technique. All yeast isolates were scrutinized for their sensitivity to killer toxin, production of non-desirable metabolites such as acetic acid and H 2 S, β-glucosidase production and resistance to the antimicrobial agent; SO 2. In parallel, S. cerevisiae isolates were typed at strain level by interdelta-PCR genomic fingerprinting. S. cerevisiae strains were examined for their fermentative capacity in laboratory scale fermentation on pasteurized grape must. Glucose and fructose consumption was monitored daily and at the final point a free sorting task was conducted to categorize the samples according to their organoleptic profile. According to our results, among the 190 isolates, S. cerevisiae was the most dominant species while some less common non-Saccharomyces species such as Trigonopsis californica, Priceomyces carsonii, Zygosaccharomyces bailii, Brettanomyces bruxellensis and Pichia manshurica were identified in minor abundancies. According to phenotypic typing, most isolates were neutral to killer toxin test and exhibited low acetic acid production. Hierarchical Cluster Analysis revealed the presence of four yeast groups based on phenotypic fingerprinting. Strain level typing reported 20 different S. cerevisiae strains from which 65% indicated fermentative capacity and led to dry wines. Sensory evaluation results clearly discriminated the produced wines and consequently, the proposed yeast categorization was confirmed. A novel approach that employs biostatistical tools for a rapid screening and classification of indigenous wine yeasts with oenological potential, allowing a more efficient preliminary selection or rejection of isolates is proposed. CITATION Tzamourani AP, Taliadouros V, Paraskevopoulos I and Dimopoulou M (2023) Developing a novel selection method for alcoholic fermentation starters by exploring wine yeast microbiota from Greece.
... The selection of indigenous yeasts, both of the Saccharomyces and non-Saccharomyces strains, is based on certain relevant enological traits that are divided into technological and qualitative categories [14,15]. Technological traits are evaluated in order to ensure an efficient fermentative process, such as high fermentation vigor; ethanol tolerance; resistance to sulfur dioxide and heavy metals; good fermentative kinetics at different temperatures; and others [13]. ...
The type and quantity of precursor amino acids present in grape must that are used by wine yeasts affect the organoleptic and health properties of wine. The aim of this work was to conduct a preliminary screening among Saccharomyces and non-Saccharomyces indigenous strains, which were previously isolated from different Italian regional grape varieties. This was performed in order to evaluate their decarboxylase activity on certain important amino acids—such as arginine, proline, serine, and tyrosine—that are present in grape must. In particular, a qualitative test on 122 wine yeasts was performed on a decarboxylase medium using arginine, proline, serine, and tyrosine as precursor amino acids. Our results showed a considerable variability among the microbial species tested for this parameter. Indeed, Saccharomyces cerevisiae strains exhibited a high decarboxylase capability of the four amino acids tested; moreover, only 10% of the total (i.e., a total of 81) did not show this trait. A high recovery of decarboxylation ability for at least one amino acid was also found for Zygosaccharomyces bailii and Hanseniaspora spp. These findings can, therefore, promote the inclusion of decarboxylase activity as an additional characteristic in a wine yeast selection program in order to choose starter cultures that possess desirable technological traits; moreover, this also can contribute to the safeguarding of consumer health.
... However, Schizosaccharomyces pombe can completely break down malic acid throughout the fermentation whereas other species takes part of its fractional break down or an incline in concentration, reliant on the strain and environment (Kapsopoulou et al., 2007;Jolly et al., 2014;Su et al., 2014;Benito et al., 2015;Hranilovic et al., 2018). Sidari et al. (2021) have tested the fermentation performances of eleven yeast strains. Non-Saccharomyces yeasts have indicated lower fermentation vigour compared to S. cerevisae yeasts which were performed the peak performance. ...
This article aims to describe non-Saccharomyces yeast and their effects on wine composition, fermentation, chemistry and organoleptic characters. The use of non�Saccharomyces yeast is on the rise in the wine industry despite the negative perception
from previous research. It is known that higher levels of non-Saccharomyces yeast could cause implications during winemaking practices. On the contrary, non-Saccharomyces yeast provides complexity, richer aroma and flavour and decreases ethanol content. If the main goal is using indigenous yeast and having a starter culture, use of non-Saccharomyces yeast collected from winery environment could be an option, yet again a risky option.
However, previous studies indicated the relation between acetic acid production and the use of non-Saccharomyces yeast. In brief, it is important to increase sanitation in the winery environment and personal awareness to maximize cleanliness and to reduce any unwanted yeast activity. More importantly, in the recent years, the use of non-Saccharomyces yeast is attracting winemakers to achieve unique wine styles, and it is an important topic that should be taken under consideration, particularly on a research basis, specifically for
targeting consumer liking-perceptions of the wine. In addition to their positive effect onsensory characters on wines, non-Saccharomyces yeasts as bio-control agents (BCAs) is also charming researchers around the globe.
... However, Schizosaccharomyces pombe can completely break down malic acid throughout the fermentation whereas other species takes part of its fractional break down or an incline in concentration, reliant on the strain and environment (Kapsopoulou et al., 2007;Jolly et al., 2014;Su et al., 2014;Benito et al., 2015;Hranilovic et al., 2018). Sidari et al. (2021) have tested the fermentation performances of eleven yeast strains. Non-Saccharomyces yeasts have indicated lower fermentation vigour compared to S. cerevisae yeasts which were performed the peak performance. ...
This article aims to describe non-Saccharomyces yeast and their effects on wine composition, fermentation, chemistry and organoleptic characters. The use of non-Saccharomyces yeast is on the rise in the wine industry despite the negative perception from previous research. It is known that higher levels of non-Saccharomyces yeast could cause implications during winemaking practices. On the contrary, non-Saccharomyces yeast provides complexity, richer aroma and flavour and decreases ethanol content. If the main goal is using indigenous yeast and having a starter culture, use of non-Saccharomyces yeast collected from winery environment could be an option, yet again a risky option. However, previous studies indicated the relation between acetic acid production and the use of non-Saccharomyces yeast. In brief, it is important to increase sanitation in the winery environment and personal awareness to maximize cleanliness and to reduce any unwanted yeast activity. More importantly, in the recent years, the use of non-Saccharomyces yeast is attracting winemakers to achieve unique wine styles, and it is an important topic that should be taken under consideration, particularly on a research basis, specifically for targeting consumer liking-perceptions of the wine. In addition to their positive effect on sensory characters on wines, non-Saccharomyces yeasts as bio-control agents (BCAs) is also charming researchers around the globe.
... However, non-Saccharomyces species can modulate the wine aroma profile, via esterase and glucosidase activities. They can also increase the glycerol content, lower the alcohol content, and exert proteolytic and pectinolytic activities that lead to enrichment of the aroma profile [8,9]. ...
Mixed fermentation using Saccharomyces cerevisiae and non-Saccharomyces yeasts as starter cultures is well known to improve the complexity of wines and accentuate their characteristics. This study examines the use of controlled mixed fermentations with the Metschnikowia pulcherrima clade, Saccharomyces cerevisiae Tokay, and non-conventional yeasts: Wickerhamomyces anomalus and Dekkera bruxellensis. We investigated the assimilation profiles, enzyme fingerprinting, and metabolic profiles of yeast species, both individually and in mixed systems. The chemical complexity of apple wines was improved using the M. pulcherrima clade as co-starters. M. pulcherrima with S. cerevisiae produced a wine with a lower ethanol content, similar glycerol level, and a higher level of volatilome. However, inoculation with the Dekkera and Wickerhamomyces strains may slightly reduce this effect. The final beneficial effect of co-fermentation with M. pulcherrima may also depend on the type of fruit must.
The domestication of vines started in Asia 11,000 years ago, although it was not until the 19th century that oenology was established as a scientific discipline thanks to the research of Louis Pasteur on the role of microorganisms in wine fermentation. At the present time, the progression in next-generation sequencing (NGS) technologies is helping to facilitate the identification of microbial dynamics during winemaking. These advancements have aided winemakers in gaining a more comprehensive understanding of the role of microbiota in the fermentation process, which, in turn, is ultimately responsible for the delivery of provisioning (wine features and its production), regulating (such as carbon storage by vineyards, regulation of soil quality, and biocontrol of pests and diseases) or cultural (such as aesthetic values of vineyard landscapes, scholarly enjoyment of wine, and a sense of belonging in wine-growing regions) ecosystem services. To our knowledge, this is the first review of the state of knowledge on the role of microbiota in the delivery of ecosystem services in the wine sector, as well as the possibility of valuing them in monetary terms by operating logic chains, such as those suggested by the SEEA-EA framework. This paper concludes with a review of management practices that may enhance the value of microbiota ecosystem services and the role of smart farming in this task.
Hanseniaspora uvarum is a prevalent yeast species in vineyards. However, its application in grape wine fermentation remains limited. This study used culture-dependent and -independent approaches to investigate the dynamics of H. uvarum during the spontaneous fermentation of Cabernet Sauvignon grapes. The results revealed that H. uvarum constituted 77.49 % of the non-Saccharomyces yeast population during fermentation. An indigenous strain, QTX-C10, was isolated from the 148 H. uvarum strains using a multistep screening strategy. The 1:1 co-inoculation of QTX-C10 with Saccharomyces cerevisiae proved to be an optimal strategy for mixed fermentation, resulting in a 48.54 %–59.55 % increase in ethyl esters in Cabernet Sauvignon wine and a 96.94 %–110.92 % increase in Chardonnay wine. Furthermore, this approach reduced the acetic acid levels by 12.50 %–17.07 % for Cabernet Sauvignon wine and 10.81 %–17.78 % for Chardonnay wine. Additionally, increased ethyl ester content may enhance the tropical fruit flavor of Cabernet Sauvignon wines.
In this study we investigated the yeast population present on partially dehydrated Nebbiolo grapes destined for ‘Sforzato di Valtellina’, with the aim to select indigenous starters suitable for the production of this wine. Yeasts were enumerated, isolated, and identified by molecular methods (5.8S-ITS-RFLP and D1/D2 domain sequencing). A genetic, physiological (ethanol and sulphur dioxide tolerance, potentially useful enzymatic activities, hydrogen sulphide production, adhesive properties, and killer activity) and oenological (laboratory pure micro-fermentations) characterization was also carried out. Based on relevant physiological features, seven non-Saccharomyces strains were chosen for laboratory-scale fermentations, either in pure or in mixed-culture (simultaneous and sequential inoculum) with a commercial S. cerevisiae strain. Finally, the best couples and inoculation strategy were further tested in mixed fermentations in winery. In both laboratory and winery, microbiological and chemical analyses were conducted during fermentation. The most abundant species on grapes were Hanseniaspora uvarum (27.4% of the isolates), followed by Metschnikowia spp. (21.0%) and Starmerella bacillaris (12.9%). Technological characterization highlighted several inter and intra-species differences. The best oenological aptitude was highlighted for species Starm. bacillaris, Metschnikowia spp., Pichia kluyveri and Zygosaccharomyces bailli. The best fermentation performances in laboratory-scale fermentations were found for Starm. bacillaris and P. kluyveri, due to their ability to reduce ethanol (-0.34% v/v) and enhance glycerol production (+0.46). This behavior was further confirmed in winery. Results of this study contribute to the knowledge of yeast communities associated with a specific environment, like those of Valtellina wine region.
