Annually, the wine industry produces high amounts of waste that can be toxic if disposed of without pretreatment. Vermicomposting is an efficient and low-cost method of decomposing organic matter using earthworms under controlled conditions. The organic substrate used in the vermicomposting process affects microbial populations and reflects the dynamics of enzymatic activity, decomposition of organic matter, and nitrogen transformations. However, the microbiome associations during the whole process are still unexplored. Thus, the aim of the present study was to investigate physicochemical, enzymatic, microbial, and microbiome activities during vermicomposting of winery waste. In this vein, a rectangular vermireactor with Eisenia andrei and Eisenia fetida earthworms, loaded with winery waste, was used. At the end of the process, the carbon/nitrogen (C/N) ratio was decreased, the total nitrogen was increased, the pH was neutralized and excess enzymatic activities were recorded. The bacterial and fungal phyla detected by next-generation sequencing analysis identified Armatimonadetes, Bacteriodetes, Candidatus saccharibacteria, Chloroflexi, Cyanobacteria, Planctomycetes, and Proteobacteria and Ascomycota, Basidiomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, and Mucoromycota, respectively. Physicochemical and microbial changes occurring during vermicomposting of winery waste, along with the microbiome diversity at the beginning and end of the process, may lead to a better understanding of winery-waste biotransformation into effective biofertilizer.

Plant extracts contain valuable sources of biologically active molecules and, lately, have attracted scientific and industrial interest as inhibitors of food-borne pathogens and growth stimulators of beneficial microbes. In this vein, the aim of this study was to explore and exploit the effect of Aloysia citrodora extracts as potent functional regulators of food microbiota by stimulating the growth of probiotic strains and by suppressing the evolution of common food-spoilage and pathogenic bacteria. Aqueous and ethanolic extracts of A. citrodora, rich in polyphenols, were prepared and their phytochemical composition was unveiled by LC-triple quadruple and LC-QToF mass spectrometry. The growth stimulatory activity of a wild-type Lacticaseibacillus rhamnosus strain, along with L. rhamnosus GG, used as a control, was assessed by monitoring cell growth in the presence of sodium chloride, bile salts, thermal stress, and alcohol. We found that the aqueous extract stimulated the growth of probiotic strains at 0.5 mg/mL. At the same concentration, stimulatory activity was observed for the wild-type L. rhamnosus in the presence of bile salts and alcohol and for L. rhamnosus GG in the presence of NaCl and under thermal stress. The ethanolic extract of A. citrodora exhibited prebiotic activity at 0.25 mg/mL, but did not promote the growth of the strains under the stress conditions tested. In addition, minimum inhibitory (MIC) and minimum bactericidal concentrations (MBC) against food-spoilage and pathogenic microbes were determined. The strongest growth inhibitory activity of foodborne pathogens was noted by the A. citrodora ethanolic extract, while the aqueous A. citrodora extract had no effect against Escherichia coli. Importantly, the spoilage and pathogenic microbes tested were more sensitive to the extracts than the probiotic strains, indicating a significant contribution to the functional regulation of food microbiota, provided that they are used at the optimum concentration.

Biofilms pose a major challenge to the food industry, as they develop on both biotic and abiotic surfaces and contribute to the persistence of antibiotic-resistant pathogens. This study evaluated the antimicrobial and antibiofilm potential of Satureja thymbra, Thymus capitatus, and Origanum hirtum essential oils (EOs), their main components (thymol, carvacrol, p-cymene, and γ-terpinene), and ethanolic and ethyl acetate extracts of the water-steam distillation residue of T. capitatus (WSTRTc). Minimum Inhibition Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values of EOs and WSTRTc extracts ranged from 0.6 to 56.8 mg/mL. The corresponding MIC values of the main components ranged in lower values (0.5–2.4 mg/mL). Minimum Biofilm Inhibition Concentration (MBIC) and Minimum Biofilm Eradication Concentration (MBEC) were also determined. MBIC values for the EOs ranged from 0.6 to 4.7 mg/mL against biofilms of Escherichia coli, Listeria monocytogenes, Proteus mirabilis, and Salmonella Enteritidis. Significant antibiofilm activity at concentrations > 61 mg/mL and > 20 mg/mL was recorded by the ethanolic and ethyl acetate WSTRTc extracts, respectively, but no activity against L. monocytogenes and P. mirabilis biofilms was documented. These findings highlighted the efficacy of EOs and extracts derived from Greek herbs, suggesting their application in the food and pharmaceutical industry as natural antimicrobials and biofilm inhibitors.

Over the past few years, consumers’ preference for wines with a distinct regional identity has shifted producers to adopt traditional grape varieties and has increased interest in the indigenous grapevine microbiome, due to its potential influence on the wine quality characteristics. In the present study, indigenous Saccharomyces cerevisiae strains were isolated from 3 local grape varieties (“Keratsouda”, “Karnachalas”, and “Bogialamas”) of the Soufli region in northern Greece. After molecular identification, all strains were evaluated for key oenological traits (ethanol resistance, SO₂ resistance, H₂S production, and aminoacid decarboxylation). Three representative strains (one per grape variety) were further evaluated for their long-term survival after freeze-drying and their fermentation potential at 12 °C and 22 °C. Ethanol content ranged in similar values (11.9–12.5%) for all wines, but kinetic parameters were significantly affected by the strain used and the fermentation temperature. Principal component analysis revealed that the volatile composition as well as practical wine attributes were affected by both the strain used and the fermentation temperature and resulted in distinct sensory profiles in the new products.

Over the past few years, consumers’ preference for wines with a distinct regional identity has shifted producers to adopt traditional grape varieties and has increased interest in the indigenous grapevine microbiome, due to its potential influence on the wine quality characteristics. In the present study, indigenous Saccharomyces cerevisiae strains were isolated from three local grape varieties (“Keratsouda”, “Karnachalas”, and “Bogialamas”) of the Soufli region in Northern Greece. After molecular identification, all strains were evaluated for key oenological traits (ethanol resistance, SO₂ resistance, H₂S production, and amino‑acid decarboxylation). Three representative strains (one per grape variety) were further evaluated for their long-term survival after freeze-drying and their fermentation potential at 12 °C and 22 °C. Ethanol content ranged in similar values (11.9–12.5%) for all wines, but kinetic parameters were significantly affected by the strain used and the fermentation temperature. Principal Component Analysis revealed that the volatile composition as well as practical wine attributes were affected by both the strain used and the fermentation temperature and resulted in distinct sensory profiles in the new products.