The aim of this review is to present the advantages and disadvantages of using non-conventional yeasts in beer production. As a whole, beer production is a traditional process, in which Saccharomyces cerevisiae and Saccharomyces pastorianus are used for ale and lager fermentation, respectively. The increasing interest in the use of non-conventional yeasts is a result of the advent of craft brewing, as well as the consumer demands for innovative and healthy beverages. Non-conventional yeasts include different species of the genus Saccharomyces, as well as species that are contaminating microflora for the various beverage productions such as Candida spp., Hanseniaspora spp., Lachancea spp., Pichia spp., Saccharomycodes spp., Schizosaccharomyces spp., Torulaspora spp. and Zygosaccharomyces spp. Non- conventional brewing strains can produce different metabolites that are potentially interesting for the production of new beer styles.

Although beer fermentation has traditionally been carried out with Saccharomyces, the boom in craft brewing has led to the use of non-conventional yeast species for beer production. This group also includes non-Saccharomyces starters, which are commonly used in winemaking and which have different technological characteristics compared to standard representatives of the Saccharomyces genus. One of the important characteristics of the non-Saccharomyces group is the richer enzyme profile, which leads to the production of beverages with different taste and aroma profiles. The aim of this study was to investigate sweet and hopped wort fermentation with seven strains of active dry non-conventional yeasts of Lachancea spp., Metschnikowia spp., Torulaspora spp. and a mixed culture of Saccharomyces cerevisiae and Torulaspora delbrueckii. One ale and one lager active dry yeast strain were used as control strains. The extract consumption, ethanol production, degree of fermentation, pH drop, as well as the yeast secondary metabolites formed by the yeast (higher alcohols, esters and aldehydes) in sweet and hopped wort were investigated. The results indicated that all of the studied types of non-conventional yeasts have serious potential for use in beer production in order to obtain new beer styles. For the purposes of this study, statistical methods, principle component analysis (PCA) and correlation analysis were used, thus establishing the difference in the fermentation kinetics of the growth in the studied species in sweet and hopped wort. It was found that hopping had a significant influence on the fermentation kinetics of some of the species, which was probably due to the inhibitory effect of the iso-alpha-acids of hops. Directions for future research with the studied yeast species in beer production are presented.

This study on the isolation, identification, and characterization of the probiotic properties of lactic acid bacterial strains from the rose blossom of Rosa damascena Mill. (R. damascena) is crucial for discovering novel, plant-derived probiotics with potential health benefits and applications in food, medicine, and cosmetics. Nine lactic acid bacterial (LAB) strains were isolated from rose blossom of R. damascena, and they were identified to the species level by applying physiological and biochemical (API 50 CHL), and molecular genetic (16S rRNA gene sequencing) methods. The isolates were identified as belonging to the Lactobacillus helveticus, Lactobacillus acidophilus, and Lactiplantibacillus plantarum species. Some probiotic properties of the newly isolated and identified LAB strains were examined: their antibacterial activity against pathogens by the agar well diffusion method, and their antibiotic resistance profile by the agar paper disc diffusion method. The LAB strains studied demonstrated significant antibacterial activity against the Escherichia coli, Staphylococcus aureus, Salmonella Abony, Proteus vulgaris, Listeria monocytogenes, and Enterococcus faecalis pathogens and were resistant to most of the antibiotics used in clinical practice, which in turn suggested the possibility of their joint inclusion in therapy, in the composition of probiotic preparations. A batch fermentation process was conducted with Lactiplantibacillus plantarum 5/20, and the kinetic parameters of the batch fermentation process were determined in order to obtain a concentrate with a high viable cell count (10¹³CFU/cm³). The resultant concentrate was freeze-dried, and freeze-dried preparations with a high viable cell count (over 10¹² CFU/g) were obtained. Research on LAB strains isolated from R. damascena could reveal valuable LAB strains with significant probiotic properties. These strains will be suitable for various applications in the composition of starter cultures for functional beverages and foods, as well as probiotic preparations, showcasing the untapped potential of plant-associated microbiota.

The study on the isolation, identification, and characterization of probiotic properties of lactic acid bacteria strains from the rose blossom of Rosa damascena Mill. is crucial for discovering novel, plant-derived probiotics with potential health benefits and applications in food, medicine, and cosmetics. Nine lactic acid bacteria (LAB) strains were isolated from rose blossom of Rosa damascena Mill. and they were identified to the species level by applying physiological-biochemical (API 50 CHL) and molecular-genetic (16S rRNA gene sequencing). The isolates were identified as representatives of the species Lactobacillus helveticus, Lactobacillus acidophilus and Lactiplantibacillus plantarum. Some probiotic properties of the newly isolated and identified LAB strains were examined: antimicrobial activity against pathogens by the agar-diffusion method with wells and antibiotic resistance profile by the agar-diffusion method with paper discs. The studied LAB strains demonstrated high antimicrobial activity against the pathogenic bacteria Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Salmonella abony NTCC 6017, Proteus vulgaris J, Listeria monocytogenes ATCC 19115, Enterococcus faecalis ATCC 29212 and were resistant to most of the antibiotics used in clinical practice, which in turn opens up the possibility of their joint inclusion in complex therapy in the composition of probiotics. A batch fermentation process was carried out with Lactiplantibacillus plantarum 5/20 and the kinetic parameters of the fermentation process to obtain a concentrate with a high content of viable cells (1013cfu/cm3) were determined. The obtained concentrate weas freeze-dried and lyophilic preparations with a high content of viable cells (over 1012 cfu/g) were obtained. This research on Rosa damascena Mill.-isolated LAB strains could uncover valuable LAB strains with significant probiotic properties. These strains would be suitable for various applications in the composition of starters for functional foods and beverages as well as probiotic preparations, showcasing the untapped potential of plant-associated microbiota.

Although the beer fermentation traditionally is carried out with Saccharomyces, the increasing interest in innovative beers lead to the use of uncharacterized autochthonous starter cultures, spontaneous fermentation, or non-Saccharomyces starters, which leads to the production of distinctive and unusual products. Non-Saccharomyces yeasts are generally characterized by low fermentation yields and are more sensitive to ethanol stress, but they provide a distinctive aroma and flavor. The aim of this study was to investigate the sweet and hopped wort fermentation with 7 strains of active dry non-conventional yeasts of the Lachancea spp, Metschnikowia spp., Torulaspora spp. and a mixed culture of Saccharomyces cerevisiae and Torulaspora delbrueckii. One ale and one lager active dry yeast strains were used as a control strains. The extract consumption, ethanol production, degree of fermentation, pH drop, as well as the yeast secondary metabolites formed by the yeast (higher alcohols, esters and aldehydes) in sweet and hopped wort was investigated. The results indicated that all of the studied types of non-conventional yeasts were with serious potential for use in beer production in order to obtain new beer styles.

Traditional fermented foods and beverages, typical of a given region, represent a source of biodiversity for the development of innovative, sustainable and health-oriented foods. Another source of biodiversity is various spices and herbs, which are typical of the diet of different countries. The aim of this work is to make a critical analysis of fermented foods and beverages typical of Bulgaria and France, as well as spices and herbs as a source of biodiversity for the development of innovative fermented and biopreserved foods. The paper focuses on methodological approaches for the isolation, identification, genetic characterization, and functional screening of lactic acid bacteria and yeasts from artisanal fermented matrices, highlighting process-relevant traits such as antimicrobial activity, probiotic potential, fermentation performance, and technological stability. In parallel, the review critically evaluates process-oriented methodologies for the selection, extraction, physicochemical characterization, and antimicrobial assessment of plant-derived bioactive compounds, including extracts and essential oils obtained from traditional herbs and spices. Finally, the compatibility between plant extracts and microbial strains used for the fermentation of foods and beverages is discussed.