The aim of this study was to assess the chemical composition, antioxidant, antimicrobial and antibiofilm activity of the
essential oil. Changes in the biofilm profile of
and
were studied using ...MALDI-TOF MS Biotyper on glass and wooden surfaces. The molecular differences of biofilms in different days were observed as well. The major volatile compounds of the coriander essential oil in the present study were
-linalool 66.07%. Coriander essential oil radical scavenging activity was 51.05% of inhibition. Coriander essential oil expressed the strongest antibacterial activity against
followed by
and
The strongest antibiofilm activity of the coriander essential oil was found against S.
A clearly differentiated branch was obtained for early growth variants of
in case of planktonic cells and all experimental groups and time span can be reported for the grouping pattern of
preferentially when comparing to the media matrix, but without clear differences among variants. The results indicate that coriander was effective against the tested
in the vapor phase after 14 days with MID
367.19 and MID
445.92 µL/L of air.
The essential oil of
, commonly known as tea tree oil, has many beneficial properties due to its bioactive compounds. The aim of this research was to characterize the tea tree essential oil (TTEO) ...from Slovakia and its biological properties, which are specific to the chemical composition of essential oil. Gas chromatography/mass spectroscopy revealed that terpinen-4-ol was dominant with a content of 40.3%. γ-Terpinene, 1,8-cineole, and
-cymene were identified in contents of 11.7%, 7.0%, and 6.2%, respectively. Antioxidant activity was determined at 41.6% radical inhibition, which was equivalent to 447 μg Trolox to 1 mL sample. Antimicrobial activity was observed by the disk diffusion method against Gram-positive (G
), Gram-negative (G
) bacteria and against yeasts, where the best antimicrobial activity was against
and
with an inhibition zone of 10.67 mm. The minimum inhibitory concentration showed better susceptibility by G
and G
planktonic cells, while yeast species and biofilm-forming bacteria strains were more resistant. Antibiofilm activity was observed against
and
by MALDI-TOF, where degradation of the protein spectra after the addition of essential oil was obtained. Good biological properties of tea tree essential oil allow its use in the food industry or in medicine as an antioxidant and antimicrobial agent.
Thymus vulgaris essential oil has potential good biological activity. The aim of the research was to evaluate the biological activity of the T. vulgaris essential oil from the Slovak company. The ...main components of T. vulgaris essential oil were thymol (48.1%), p-cymene (11.7%), 1,8-cineole (6.7), γ-terpinene (6.1%), and carvacrol (5.5%). The antioxidant activity was 85.2 ± 0.2%, which corresponds to 479.34 ± 1.1 TEAC. The antimicrobial activity was moderate or very strong with inhibition zones from 9.89 to 22.44 mm. The lowest values of MIC were determined against B. subtilis, E. faecalis, and S. aureus. In situ antifungal analysis on bread shows that the vapor phase of T. vulgaris essential oil can inhibit the growth of the microscopic filamentous fungi of the genus Penicillium. The antimicrobial activity against S. marcescens showed 46.78–87.80% inhibition at concentrations 62.5–500 µL/mL. The MALDI TOF MS analyses suggest changes in the protein profile of biofilm forming bacteria P. fluorescens and S. enteritidis after the fifth and the ninth day, respectively. Due to the properties of the T. vulgaris essential oil, it can be used in the food industry as a natural supplement to extend the shelf life of the foods.
Designing CD8+ T‐cell vaccines, which would provide protection against tumors is still considered a great challenge in immunotherapy. Here we show the robust potential of cytomegalovirus (CMV) vector ...expressing the NKG2D ligand RAE‐1γ as CD8+ T cell‐based vaccine against malignant tumors. Immunization with the CMV vector expressing RAE‐1γ, delayed tumor growth or even provided complete protection against tumor challenge in both prophylactic and therapeutic settings. Moreover, a potent tumor control in mice vaccinated with this vector can be further enhanced by blocking the immune checkpoints TIGIT and PD‐1. CMV vector expressing RAE‐1γ potentiated expansion of KLRG1+ CD8+ T cells with enhanced effector properties. This vaccination was even more efficient in neonatal mice, resulting in the expansion and long‐term maintenance of epitope‐specific CD8+ T cells conferring robust resistance against tumor challenge. Our data show that immunomodulation of CD8+ T‐cell responses promoted by herpesvirus expressing a ligand for NKG2D receptor can provide a powerful platform for the prevention and treatment of CD8+ T‐cell sensitive tumors.
RAE‐1γMCMV vector promotes induction of epitope specific KLRG1‐expressing CD8 T cells with enhanced effector functions providing superior protection against tumor challenge.
Mill. is a medicinal plant, used as a flavouring agent. The essential oil from
has potential antimicrobial and insecticidal effects, and can be used in food industry in order to protect the food ...resources and food products against microbial and pest’s contamination. The aim of the research was to characterize the volatile components of
essential oil by Gas Chromatography/Mass Spectrometry (GC/MS) and Gas Chromatography (GC-FID) and to observe the antimicrobial activity by disk diffusion method and in vapour phase. Also, insecticidal activity of the vapour phase of the essential oil of
was detected. We found that major components of the essential oil from
were
anethole (73.6%), fenchone (6.0%), and limonene (5.7%). Antimicrobial activity on gram-positive, gram-negative, and yeasts was weak in liquid phase, but vapour phase showed stronger activity against
at the concentration 250 μL.L
(98.65% of bacterial growth inhibition). Vapour phase of essential oil was effective against insects, where 25% concentration had 80% lethality.
The main aim of the study was to investigate the chemical composition, antioxidant, antimicrobial, and antibiofilm activity of
essential oil (CAEO). The biofilm profile of
and
were assessed using the ...mass spectrometry MALDI-TOF MS Biotyper and the antibiofilm activity of
(CAEO) was studied on wood and glass surfaces. A semi-quantitative composition using a modified version was applied for the CAEO characterization. The antioxidant activity of CAEO was determined using the DPPH method. The antimicrobial activity was analyzed by disc diffusion for two biofilm producing bacteria, while the vapor phase was used for three penicillia. The antibiofilm activity was observed with the agar microdilution method. The molecular differences of biofilm formation on different days were analyzed, and the genetic similarity was studied with dendrograms constructed from MSP spectra to illustrate the grouping profiles of
and
. A differentiated branch was obtained for early growth variants of
for planktonic cells and all experimental groups. The time span can be reported for the grouping pattern of
preferentially when comparing to the media matrix, but without clear differences among variants. Furthermore, the minimum inhibitory doses of the CAEO were investigated against microscopic fungi. The results showed that CAEO was most active against
, in the vapor phase, on bread and carrot in situ.
The aim of this study was to analyze the chemical composition and biological and antibiofilm activity of the essential oil (EO) of Thymus serpyllum with the use of a MALDI-TOF MS Biotyper. The main ...compounds of the EO were thymol, 18.8%; carvacrol, 17.4%; o-cymene, 15.4%; and geraniol, 10.7%. It was found that free-radical scavenging activity was high. The highest antimicrobial activity was observed against Pseudomonas aeruginosa, Salmonella enteritidis, and biofilm-forming bacteria. The changes in the biofilm structure after T. serpyllum EO application confirmed the inhibitory action and the most pronounced effect was observed on Bacillus subtilis biofilm. The antifungal activity of the vapor phase was the most effective against Penicillium crustosum. T. serpyllum should be a suitable alternative to synthetic antioxidants as well as antimicrobials. The EO of T. serpyllum can be used in the vapor phase in the storage of root vegetables as well as a growth inhibitor of Penicillium on bread.
Antimicrobial in vitro and in situ efficacies of Cymbopogon citratus essential oil (lemongrass, LGEO) against 17 spoilage microorganisms (bacteria, yeasts and fungi) were evaluated. Additionally, its ...chemical composition, and antioxidant and antibiofilm activities were investigated. The LGEO exhibited a strong antioxidant activity (84.0 ± 0.1%), and its main constituents were citral (61.5%), geraniol (6.6%) and 1,8-cineole (6.4%). An in vitro antimicrobial evaluation revealed the lowest inhibition zone (1.00 ± 0.00 mm) in Pseudomonas fluorescens, and the highest inhibition zone (18.00 ± 2.46 mm) in Candida krusei. The values for the minimal inhibitory concentration were determined to be the lowest for Salmonella enteritidis and the highest for C. albicans. Furthermore, the concentration of ≥250 µL/L of LGEO suppressed the growth of Penicillium aurantiogriseum, Penicillium expansum, Penicillium chrysogenum and Penicillium italicum. The changes in the molecular structure of the biofilms produced by Pseudomonas fluorescens and Salmonella enteritidis, after their treatment with LGEO, confirmed its action on both biofilm-forming bacteria. Moreover, an in situ antimicrobial activity evaluation displayed the most effective inhibitory effectiveness of LGEO against Micrococcus luteus, Serratia marcescens (250 µL/L) and Penicillium expansum (125, 250 and 500 µL/L) growing on a carrot. Our results suggest that LGEO, as a promising natural antimicrobial agent, can be applied in the innovative packaging of bakery products and different types of vegetables, which combines commonly used packing materials with the addition of LGEO.
This study aimed to analyze the biological activity of the essential oil Pogostemon cablin (PCEO) to determine the antioxidant, antimicrobial, antibiofilm, insecticidal activity, and chemical ...composition of the essential oil. We analyzed the structure of biofilms on various surfaces using the MALDI-TOF MS Biotyper and evaluated the antimicrobial effect of the vapor phase of the essential oil in a food model. We determined the main volatile components of PCEO as patchouli alcohol 31.0%, α-bulnesene 21.3%, and α-guaiene 14.3%. The free radical scavenging activity was high and reached 71.4 ± 0.9%, corresponding to 732 ± 8.1 TEAC. The antimicrobial activity against bacteria was weak to moderate. We recorded strong activity against yeast. The antifungal activity was very weak in the contact application. Biofilm-producing bacteria were moderately inhibited by PCEO. The change in biofilm structure due to essential oil was demonstrated by MALDI-TOF MS Biotyper analysis. Vapor phase application in a food model showed relatively strong effects against bacteria and significantly higher antifungal efficacy. The insecticidal activity was observed only at higher concentrations of essential oil. Based on the findings, PCEO can be used in the food industry as an antifungal substance in extending the shelf life of bakery products and as protection in the storage of root vegetables.
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