This study aimed to investigate in vitro the probiotic potential of three yeasts strains (BB06, OBT05, and MT07) isolated from agro-food natural sources. Screening was performed, including several functional, technological, and safety aspects of the yeast strains, in comparison to a reference Saccharomyces boulardii, to identify the ones with suitable probiotic attributes in aquaculture. The yeast strains were identified by 5.8S rDNA-ITS region sequencing as Metschnikowia pulcherrima OBT05, Saccharomyces cerevisiae BB06, and Torulaspora delbrueckii MT07. All yeast strains were tolerant to different temperatures, sodium chloride concentrations, and wide pH ranges. S. cerevisiae BB06 showed a strong and broad antagonistic activity. Moreover, the S. cerevisiae strain exhibited a high auto-aggregation ability (92.08 ± 1.49%) and good surface hydrophobicity to hexane as a solvent (53.43%). All of the yeast strains have excellent antioxidant properties (>55%). The high survival rate in the gastrointestinal tract (GIT) can promote yeast isolates as probiotics. All yeast strains presented a resistance pattern to the antibacterial antibiotics. Non-hemolytic activity was detected. Furthermore, freeze-drying with cryoprotective agents maintained a high survival rate of yeast strains, in the range of 74.95–97.85%. According to the results obtained, the S. cerevisiae BB06 strain was found to have valuable probiotic traits.

Romania has a long history of grapevine culturing and winemaking. However, like any agricultural sector, viticulture faces devastating biological threats. Fungi responsible for grapevine trunk diseases (GTDs) and grape spoilage lead to considerable yield losses and a decline in grapevine quality. In the actual context, many countries, including Romania, have reoriented their approaches to minimize chemical inputs, which have been proven to be toxic and to have negative impacts on the environment, and to replace them with sustainable biocontrol strategies for the wine-growing sector. Within biocontrol strategies, Bacillus spp. is a well-known plant-protective bacteria with antifungal properties. Within this paper, six endophytic bacteria from various plant sources were studied. The bacterial strains were identified as B. pumilus, B. subtilis, and B. velezensis by sequencing their 16S rDNA region. Regardless of the in vitro test methods (using living bacterial cells, bacterial-cell-free supernatant (CFS), and volatile active compounds (VOCs)), B. velezensis strains revealed strong and broad antifungal activity against grape and grapevine fungal pathogens such as Aspergillus spp., Botrytis cinerea, Penicillium expansum, Diplodia seriata, Eutypa lata, Fusarium spp., Clonostachys rosea, Neofusicoccum parvum, and Stereum hirsutum. The functional antifungal genes encoding for difficidin, fengycin, iturins, macrolactin, and mycosubtilin were molecularly detected, which could support the proven antifungal activity of the endophytic strains. Lytic enzymes involved in fungal growth inhibition, such as chitinase, cellulase, and proteases, were also revealed to be produced by some of these bacterial strains. Various other in vitro tests, such as phosphate and phytate solubilization, phytohormone synthesis, the production of enzymes involved in the polyamine biosynthetic pathway, and pH as well as temperature tolerance tests were carried out to reveal the plant-beneficial potential of these bacterial strains. These results revealed that the B. velezensis strains, especially BAHs1, are the most suitable endophytes for grapevine biologic control, which could lead to the future development of sustainable management strategies.

In recent years, research on yeasts as probiotics has gained more and more interest, which will allow the development of “new” products in the probiotics market. In this context, seventeen yeast strains isolated from Rabilé, a traditional beer produced in Burkina Faso, were assessed for their probiotic attributes. The yeast identification was performed by molecular methods, including PCR-RFLP and 5.8S-ITS region sequencing. Saccharomyces cerevisiae (14 strains) was the predominantly identified species, followed by Pichia kudriavzevii (2 strains) and Rhodotorula mucilaginosa (1 strain). Except for R. mucilaginosa, all yeast strains grew well at human temperature. The yeast strains showed high resistance when they were exposed to simulated gastrointestinal conditions. Auto-aggregation ability was between 70.20 ± 10.53% and 91.82 ± 1.96%, while co-aggregation with E. coli ranged from 24.92 ± 3.96% to 80.68 ± 9.53% and with S. enterica serovar Typhimurium from 40.89 ± 8.18% to 74.06 ± 7.94%. Furthermore, the hydrophobicity of isolated strains toward n-hexane was in the range from 43.17 ± 5.07% to 70.73 ± 2.42%. All yeast strains displayed high antioxidant capabilities, and the strains did not show hemolysis halos, such that they can be considered safe. Additionally, S. cerevisiae strains strongly inhibited the growth of foodborne pathogens. This is the first preliminary study to identify and characterize the yeast strains isolated from Rabilé with interesting probiotic properties.

The remarkable metabolic adaptability of Bacillus velezensis, including efficient nutrient use, spore formation, and the secretion of antimicrobial peptides, supports its expanding role in biotechnological applications ranging from crop protection to probiotic development. In this study, the halotolerant strain 24.5 was identified as B. velezensis through 16S rDNA and gyrA gene sequencing. PCR analyses confirmed the presence of genes responsible for polyketides, lipopeptides, and dipeptides biosynthesis. These results indicate the potential for the production of structurally diverse bioactive metabolites. Strain 24.5 demonstrated remarkable antimicrobial activity against 19 bacterial pathogens and three Candida species (p < 0.05). The study demonstrated high survival rates under simulated gastrointestinal conditions, suggesting strong adaptability for gut colonization. Antioxidant evaluation revealed DPPH radical scavenging activities of 34.68% for intact cells and 18.47% for the cell-free extract (p < 0.05). The enzymatic profile highlighted versatile metabolic functions, supporting its multifaceted probiotic potential. Auto-aggregation reached 84.42% at 24 h, and high hydrophobicity toward hexane (71.62%) supported adhesion potential. Antibiotic susceptibility profiling showed sensitivity or intermediate susceptibility to 22 of 24 tested antibiotics (p < 0.05). No haemolytic activity was detected, supporting its safety profile. Overall, these results emphasise the adaptability and multifunctional properties of Bacillus velezensis strain 24.5, highlighting its potential as a promising probiotic candidate for applications in food safety and biotechnology.

Food illnesses can occur due to the presence of human pathogen contaminants in fresh farm products. Herbs, vegetables and fruits, especially from organic agriculture, are highly exposed to animal and human pathogens. However, safe microbial antagonists, approved for plant protection, could be a solution to prevent this health risk to occur. The aim of this study is to reveal several beneficial bacterial strains reducing the prevalence of human and animal pathogens. Tested beneficial strains were previously described as promising biocontrol agents against soilborne pathogens of field crops and vegetables. Moreover, their endophyte adaptation, ensures an intimate relation with their plant hosts. Therefore, within this study we analyzed the inhibitory activity of seven biocontrol endophytes against 24 reference bacterial strains, of which 19 important human and animal pathogens. Some of the tested beneficial strains revealed antibacterial activity against a wide spectrum of pathogens, such as: Bacillus cereus, Enterococcus faecalis, Escherichia coli, Listeria ivanovii, L. monocytogenes, Rhodococcus equi, Salmonella enterica, S. typhimurium, Staphylococcus aureus, S. epidermidis and Streptococcus pyogenes. Due to their antagonistic activity, the beneficial strains were studied through molecular techniques to reveal their functional genes involved in antimicrobial compounds synthesis. Genes encoding for iturin A, surfactin, bacilysin, bacillomycin and bacillaene were found in these biocontrol strains. Therefore, we could consider such beneficial strains as promising candidates for plant protection and human safety.

This study aimed to investigate the biochemical content and antioxidant activity of methanol extracts prepared from Synsepalum dulcificum dried fruits. The results obtained by phytochemical screening of the extracts revealed the presence of some pharmacologically active chemical compounds such as: alkaloids, flavonoids, phenolic compounds and tannins. Quantitative analysis showed that the seeds had phenols in greater amounts (157.88 ± 2.09 mg GAE / g dry matter) than dried fruit pulp (54.09 ± 2.24 mg GAE / g dry matter). Contrariwise, flavonoid content was found to be low in seed (0.013 ± 0.02 mg EQ / g) and high in fruit pulp (0.13 ± 0.05 mg EQ / g). Correlated with the high amount of total phenol, in the seed extracts was found a good antioxidant activity – measured by both DPPH and ferric reducing antioxidant power (FRAP) assays. This antioxidant capacity may be also correlated with the amount of alkaloids, flavonoids, tannins and phenolic compounds, and as well as with their synergistic interactions. Synsepalum dulcificum fruits can be used as a healthy source of additives for the food industry or as natural antioxidants for the pharmaceutical industry.