Influence of essential oils on the growth of aspergillus flavus

Abstract

This paper was focused on the determination of the inhibitory effect of selected essential oils on growth of ten isolates of Aspergillus flavus and their potential ability to produce mycotoxins in vitro by TLC method. The isolates were obtained from moldy bread of domestic origin. We followed the impact of five essential oils at 100% concentrationlemon, eucalyptus, oregano, sage and thyme. The effect of the essential oils we tested the gaseous diffusion method. We isolates grown on CYA (Czapek yeast extract agar), in the dark at 25 1 °C, 14 days. The diameter of colonies grown we continuously measured on the 3 rd , 7 th, 11 th , and 14 th day of cultivation. The results of the paper suggest that oregano and thyme essential oil had 100% inhibited the growth of all tested isolates of Aspergillus flavus. Lemon, eucalyptus and sage essential oil had not significant inhibitory effects on tested isolates Aspergillus flavus, but affected the growth of colonies throughout the cultivation. In addition to the inhibitory effect we witnessed the stimulative effect of lemon, eucalyptus and sage essential oil to some isolates. Together with the antifungal effect of essential oils, we monitored the ability of Aspergillus flavus isolates to produce mycotoxinsaflatoxin B 1 (AFB 1 ) and cyclopiazonic acid (CPA) in the presence of essential oils. Production mycotoxins we have seen in the last (14 th ) day of cultivation. Lemon and eucalyptus essential oil did not affect the production of mycotoxins. In the case of sage essential oil we were recorded cyclopiazonic acid production in three of the ten isolates from the all three repetitions, while neither isolate did not produced aflatoxin B 1 . The production of secondary metabolites was detected in all control samples. From the results we can say that oregano and thyme essential oil could be used as a natural preservative useful in the food industry.

The Vapor Phase of Selected Essential Oils and Their Antifungal Activity In Vitro and In Situ against Penicillium commune, a Common Contaminant of Cheese

“…Their results show a very good inhibitory effect of these EOs. The similar results with sage EO against CPA production obtained by Foltinová et al [ 56 ] and with basil EO against aflatoxins production was reported by authors Nazzaro et al [ 57 ]. A high inhibitory effect of CPA production in both tested strains of P. commune (more than 50%) in bergamot (83.33% for P. commune KMi–183) and rosemary (66.67% for P. commune Kmi–402) Eos were determined.…”

“…Litsea (MID 50 35.26 μL/L and MID 90 43.49 μL/L after 14 days of cultivation; MID 50 54.20 μL/L and MID 90 79.37 μL/L after 35 days of cultivation) and clove (MID 50 56.84 μL/L and MID 90 98.91 μL/L after 14 days of cultivation; MID 50 74.56 μL/L and MID 90 86.06 μL/L after 35 days of cultivation) EOs were also the most effective, with a significant growth inhibition of the P. commune KMi–183 strain. Excellent antifungal effects at reduced concentrations in the vapor phase of EOs were confirmed with litsea [ 11 , 29 , 30 ] and clove EOs [ 10 , 20 , 21 , 56 ] in previous studies.…”

The Use of Essential Oils from Thyme, Sage and Peppermint against Colletotrichum acutatum

“…The EO is commonly described as secondary metabolites with high defence plant effect as they have antimicrobial properties and are non-toxic and biodegradable [ 13 , 14 , 15 , 16 , 17 ]. Harvest dates, storage period, plant extraction method, and climate may affect plant essential oils’ chemical compositions.…”

“…S. officinalis EO affects Fusarium spp. growth [ 15 ]. M. piperita EO inhibits the spread of Alternaria spp.…”

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

“…Therefore, in recent years, there has been increasing interest in searching for biological antifungal agents to replace synthetic pesticides. Among natural antimicrobial products, particularly interesting are plant products such as essential oils (EOs), which are some of the most promising phytochemicals and can be used for the preservation of cereals and their products (Singh et al 2010; Boukaew et al 2017; Foltinová et al 2017; Gakuubi et al 2017). …”