In our research six different mint species (peppermint, spearmint (five different chemotypes), Horse mint, mojito mint, apple mint (two different chemotypes), bergamot mint) have been evaluated by referring to their chemical (essential oil (EO) content and composition) and in vitro biological (antibacterial, antioxidant effect) characteristics. The EO amount of the analyzed mint populations varied between 1.99 and 3.61 mL/100 g d.w. Altogether, 98 volatile compounds have been detected in the oils. Antibacterial effects (inhibition zones, MIC, IC₅₀ and MBC) were evaluated against Escherichia coli, Salmonella enterica, Bacillus cereus and Staphylococcus aureus. The best antibacterial effect was given by a carvacrol–thymol chemotype spearmint population (inhibition zone: 18.00–20.00 mm, MIC: 0.06 v/v%, IC₅₀: 0.01–0.03 v/v%, MBC: 0.06, >2.00 v/v%). The least effective oil in the case of Gram-negative bacteria was bergamot mint (inhibition zone: 7.67–8.67 mm, MIC: 2.00, >2.00 v/v%, IC₅₀: 0.11–0.25 v/v%, MBC: 2.00, >2.00 v/v%), while in the case of Gram-positive bacteria, oils containing dihydrocarvone as the main compound possessed the weakest antibacterial effect (inhibition zone: 9.00–10.00 mm, MIC: 1.00–2.00 v/v%, IC₅₀: 0.22–0.37 v/v%, MBC: >2.00 v/v%). Interestingly, none of the oils could kill B. cereus in the applied concentrations.

The purpose of this study was to determine the effectiveness of a phytobiotic-prebiotic feed additive (PPFA, which contains a combination of chicory and extracts of carob pulp and fenugreek) in the diets of fattening pigs on growth indicators, carcass characteristics, and fecal microbiota. A total of 329 crossbred pigs were randomly divided into two dietary treatments, including a basal diet without additives as the control group and a basal diet supplemented with 1 kg/T PPFA as the trial group. The PPFA supplementation led to a significant increase in the body weight gain and average daily gain of the trial group compared to those of the control group after 70 days of feeding. Through the S-EUROP evaluation system, we also found that the fattening pigs fed PPFA significantly improved their carcass indicators. Furthermore, it was shown that PPFA regulated porcine intestinal microbiota, including promoting the growth of the beneficial commensal bacteria (i.e., Bifidobacterium and Lactobacillus) while inhibiting some potential pathogen bacteria (i.e., Bacteroidaceae and Campylobacteraceae). Our work revealed that the phytobiotic-prebiotic feed additive containing carob pulp, chicory, and fenugreek positively influences the intestinal microbiota, growth performance, and carcass traits in fattening swine.

A wide range of phytobiotic feed additives are available on the market claiming to have beneficial effects on the growth of the host animal and to promote the development of a balanced microflora. The present study investigated the effects of the phytobiotic-prebiotic mixture of curcumin, wheat germ, and chicory on the growth performance and on the intestinal microflora composition of weaning piglets. Post weaning diarrhea causes significant losses for the producers, most commonly it is prevented by feeding high doses of zinc oxide (ZnO). The effect of a phytobiotic-prebiotic feed additive (1 kg T^-1) was compared to a positive control (3.1 kg T^-1 ZnO) and to a negative control (no feed supplement) in an in vivo animal trial. There was no significant difference in the final body weight and average daily gain of the trial and positive control groups, and both groups showed significantly (P<0.05) better results than the negative control. The feed conversion ratio of the phytobiotic-prebiotic supplemented group was significantly improved (P<0.05) compared to both controls. Both phytobiotic-prebiotic mixture and ZnO were able to significantly reduce (P<0.05) the amount of coliforms after weaning, even though ZnO reduced the amount of coliforms more efficiently than the trial feed additive, it also reduced the amount of potentially beneficial bacteria. Metagenomic data also corroborated the above conclusion. In the trial and positive control groups, the relative abundance of Enterobacteriaceae decreased by 85 and 88% between 3 weeks and 6 weeks of age, while in the negative control group a slight increase occurred. Lactobacillaceae were more abundant in the trial group (29.98%) than in the positive (8.67%) or in the negative (22.45%) control groups at 6 weeks of age. In summary, this study demonstrated that a phytobiotic-prebiotic feed additive may be a real alternative to ZnO for the prevention of post weaning diarrhea and promote the development of a balanced gut system.

Chemistry, in vitro antioxidant, and antimicrobial effects of Mentha × villosa and its parental species, Mentha spicata and Mentha suaveolens, are discussed. This is the first review of the terpene and phenolic composition of M. × villosa . The volatile chemistry of M. × villosa is evaluated in the mirror of the parental species, discussed based on structural-biogenetical groups of their terpenoids. In spearmint, there is a wide diversity, involving multiple groups of monoterpenes (such as linalool or cymyl compounds). The main volatile components in M. suaveolens are usually rotundifolone or carvone, and these compounds also determine the chemotype in M. × villosa . However, contrary to the parental taxa, M. × villosa chemotypes seem connected to geographical origin. The polyphenol profile of the three taxa is also surveyed, in the framework of shikimate metabolism of genus Mentha . This means especially the high amounts of rosmarinic acid accompanied by flavanones and a variety of flavones. Even flavonols are major components, although they are considered atypical in Mentha . The preparation and extraction methods are also presented for better comparison between compositional data and a survey of methods for the extraction of polyphenols. Regarding bioactivity, much less experimental work has been done on M. × villosa than on the parental taxa. M. × villosa can be a prospective medicinal plant not only used for flavoring. It can be a substitution for carvone-type spearmint. However, much more work is necessary to optimize its cultivation, focusing on different types of components and defining its biological activity properly.

Novel wine yeast strains have the potential to satisfy customer demand for new sensorial experiences and to ensure that wine producers have strains that can produce wine as efficiently as possible. In this respect, hybrid yeast strains have recently been the subject of intense research, as they are able to combine the favourable characteristics of both parental strains. In this study, two Saccharomyces “Kéknyelű” grape juice isolates were identified by species-specific PCR and PCR-RFLP methods and investigated with respect to their wine fermentation potential. Physiological characterization of the isolated strains was performed and included assessment of ethanol, sulphur dioxide, temperature and glucose (osmotic stress) tolerance, killer-toxin production, glucose fermentation ability at 16 °C and 24 °C, and laboratory-scale fermentation using sterile “Kéknyelű” must. Volatile components of the final product were studied by gas chromatography (GC) and mass spectrometry (MS). One isolate was identified as a S. cerevisiae × S. kudriavzevii hybrid and the other was S. cerevisiae. Both strains were characterized by high ethanol, sulphur dioxide and glucose tolerance, and the S. cerevisiae strain exhibited the killer phenotype. The hybrid isolate showed good glucose fermentation ability and achieved the lowest residual sugar content in wine. The ester production of the hybrid strain was high compared to the control S. cerevisiae starter strain, and this contributed to the fruity aroma of the wine. Both strains have good oenological characteristics, but only the hybrid yeast has the potential for use in wine fermentation.

The impact of chemical fertilization on rhizosphere soil communities is a growing concern due to the changes they cause on microbes in soil ecosystems. The present study aims to compare mycorrhizal inoculation and fertilizer applications on bacterial and fungal communities in rhizosphere soil of intensively cultivated Robinia pseudoacacia and Populus × euramericana plantations using the Illumina Miseq sequencing platform. Our results revealed that the different host plants and applied treatments did not significantly affect soil bacterial diversity, but interfered with native rhizosphere bacterial communities in plantation sites. In contrast, host plants and inorganic fertilizer had a strong effect at the family and genus level on the composition of soil fungal communities. In conclusion, our findings suggest that the structure and composition of the fungal community are more sensitive to the nutrient sources in soil than bacteria.