Antifungal activity of selected essential oils against Fusarium culmorum and F. graminearum and their secondary metabolites in wheat seeds.

Essential oils (EOs) are products of plant origin and include mixtures of different chemical compounds. These volatile substances have many interesting properties, including antifungal properties. Fungi may develop under field conditions on crops such as wheat or corn and are able to synthesize mycotoxins, which adversely affect livestock and human health. In the present study, selected EOs were used to inhibit the growth of Fusarium graminearum and F. culmorum and reduce the concentrations of mycotoxins in wheat grain. The EOs significantly inhibited the growth of tested Fusarium species (90.99-99.99%), as determined based on ergosterol quantitative analysis. Only the addition of orange oil to F. culmorum exhibits a different inhibition capacity (68.13%). EO application resulted in a large reduction in zearalenone content (99.08-99.99%); only in the case of orange oil application was the reduction estimated at approximately 68.33%. However, all EOs provided a significant reduction in the concentration levels of group B trichothecenes (94.51-100%). It can be concluded that EOs inhibit the growth of fungi of the genus Fusarium and reduce concentration levels of the mycotoxins zearalenone and group B trichothecenes.

The Efficiency of Deoxynivalenol Degradation by Essential Oils under In Vitro Conditions.

Essential oils (EOs) are complex natural products of plant origin and exhibit different desirable, e.g., antimicrobial properties. Their growth inhibition effect on the pathogenic fungi of the genus, Fusarium, which forms deoxynivalenol (DON), has been documented. DON is the most common contaminant of grains and their products, causing strong emetic effects after their consumption. The aim of the study was to investigate the ability of selected EOs to degrade DON under in vitro conditions, using various incubation terms. The impact of a different temperature, pH, incubation time, mycotoxin, and essential oil concentration was tested. The results indicate that the kind of EO influences the effectiveness of mycotoxin level reduction, and the most effective EOs were palmarosa and lemon oils. A higher reduction of DON content by EOs was achieved after 24 h of the experiment (up to 72%), at a pH range between 3 and 6 and a temperature of 20 °C. Moreover, the effect of various doses of white and pink grapefruit and palmarosa EOs (100 and 200 µL/mL) on toxin level reduction was observed. The experiment confirmed that the selected EOs may be effective in DON reduction, as previously documented in experiments with zearalenone.

The Inhibitory Potential of Selected Essential Oils on Fusarium spp. Growth and Mycotoxins Biosynthesis in Maize Seeds.

Owing to their rich chemical composition, essential oils (EOs) have many interesting properties, including antimicrobial activities. The presence of Fusarium and their secondary metabolites, mycotoxins, in cereal crops is a serious problem in agriculture, which consequently affects food quality. The aim of the present study was to investigate the effects of selected EOs on the growth of Fusarium graminearum and F. culmorum and the biosynthesis of mycotoxins in maize seeds. Chromatographic analysis of ergosterol as a fungal growth indicator showed a significant inhibition of Fusarium growth (83.24-99.99%) compared to the control samples, which as a consequence resulted in a reduction in mycotoxin concentrations. The addition of cinnamon, palmarosa, orange, and spearmint EOs was shown to be the most effective in reducing zearalenone concentration (99.10-99.92%). Deoxynivalenol analysis confirmed a very high reduction of this compound at the application all tested EOs (90.69-100%). The obtained results indicated that EOs have a great potential to inhibit growth of Fusarium fungi as well as reduce the concentration of mycotoxins in maize seed.

The efficiency of lactic acid bacteria against pathogenic fungi and mycotoxins.

Mycotoxins are produced by some fungal species of the genera Aspergillus, Penicillium, and Fusarium and are common contaminants of a wide range of food commodities. Numerous strategies are used to minimise fungal growth and mycotoxin contamination throughout the food chain. This review addresses the use of lactic acid bacteria, which can inhibit fungal growth and participate in mycotoxin degradation and/or removal from contaminated food. Being beneficial for human and animal health, lactic acid bacteria have established themselves as an excellent solution to the problem of mycotoxin contamination, yet in practice their application in removing mycotoxins remains a challenge to be addressed by future research.

The effect of fertiliser treatments on the severity of Fusarium head blight and mycotoxin biosynthesis in winter rye.

The fungi of the genus Fusarium cause Fusarium head blight (FHB), a devastating disease that reduces grain yield and quality. They also produce mycotoxins which may pose a serious threat to human and animal health. This study investigated the effects of NPK fertilisation, foliar application of Cu, Zn, and Mn, applied separately and in combination, and of the Nano-Gro® organic growth stimulator on the occurrence of FHB in cultivar Dankowskie Diament rye based on the mycological analysis of kernels and on the concentrations of Fusarium mycotoxins in grain. The severity of FHB caused by seven species of the genus Fusarium was influenced by weather conditions in the analysed growing seasons. The applied fertilisation and the Nano-Gro® organic growth stimulator exerted varied effects on FHB development and the biosynthesis of Fusarium mycotoxins (deoxynivalenol, nivalenol, zearalenone and fumonisins) in grain. The greatest reduction in deoxynivalenol and nivalenol concentrations was noted in 2013, and the levels of moniliformin were lower in treated samples than in absolute control (untreated) samples in both years of the study. The severity of FHB positively correlated with the concentrations of zearalenone, deoxynivalenol, nivalenol, and moniliformin in the grain samples. Greater accumulation of ergosterol was noted in the rye grain harvested in 2013 than in 2012, and fertiliser treatment led to higher ergosterol concentrations than did control treatment.

Degradation of Zearalenone by Essential Oils under In vitro Conditions.

Essential oils are volatile compounds, extracted from plants, which have a strong odor. These compounds are known for their antibacterial and antifungal properties. However, data concerning degradation of mycotoxins by these metabolites are very limited. The aim of the present study was to investigate the effect of essential oils (cedarwood, cinnamon leaf, cinnamon bark, white grapefruit, pink grapefruit, lemon, eucalyptus, palmarosa, mint, thymic, and rosemary) on zearalenone (ZEA) reduction under various in vitro conditions, including the influence of temperature, pH, incubation time and mycotoxin and essential oil concentrations. The degree of ZEA reduction was determined by HPLC method. It was found that the kind of essential oil influences the effectiveness of toxin level reduction, the highest being observed for lemon, grapefruit, eucalyptus and palmarosa oils, while lavender, thymic and rosemary oils did not degrade the toxin. In addition, the decrease in ZEA content was temperature, pH as well as toxin and essential oil concentration dependent. Generally, higher reduction was observed at higher temperature in a wide range of pH, with clear evidence that the degradation rate increased gradually with time. In some combinations (e.g., palmarosa oil at pH 6 and 4 or 20°C) a toxin degradation rate higher than 99% was observed. It was concluded that some of the tested essential oils may be effective in detoxification of ZEA. We suggested that essential oils should be recognized as an interesting and effective means of ZEA decontamination and/or detoxification.

Occurrence of fungal metabolites--fumonisins at the ng/L level in aqueous environmental samples.

The B-series fumonisins (FBs) are some of the most prevalent mycotoxins produced as a secondary metabolite by Fusarium species growing on cereals. For decades they have been studied extensively in food and feed products, but there is no information about their occurrence in the aquatic environment or about how these mycotoxins are transported to the surface water and the groundwater. The aim of this study was to clarify the causes of fumonisin occurrence in aquatic ecosystems by examining the relation between mycotoxin contamination of crops and their levels in the aquatic environment. Water samples were collected from drainage ditches and wells or watercourses located in agricultural areas in the Wielkopolska region, Poland. Our research conducted on an annual basis showed the seasonal variability of fumonisin B1 concentration in the analyzed water samples, with the highest concentration in the post-harvest season (September to October) at 48.2 ng L(-1), and the lowest in winter and spring at 21.9 ng L(-1). Fumonisins B2 and B3 in water samples were not detected. Cereal samples were collected in the harvest season from each agricultural area close to tested water bodies. Mycotoxins were present in all cereal samples at concentrations from 43.3 to 1055.9 ng g(-1). Our results confirm that fumonisins are transported to aquatic systems by rainwater through soil. On the basis of available literature, this is the first report concerning the presence of fumonisin B1 in different aquatic environments. To date their ecotoxicological effects are largely unknown and require further investigation.