Search

Species of the Rhizopus genus are often involved in the moulding of bread and bakery products. Essential oils (EOs) are a suitable alternative to extend the shelf life of food. This research was focused on testing the effect of selected EOs on the growth of Rhizopus species. Tested strains were isolated from mouldy breads. The antifungal activity of EOs against R. stolonifer and R. oryzae strains was determined by micro-atmospheric method (625 μL EO/L air) during 7 days of cultivation. Eight EOs, thyme, red thyme, savory, caraway, marjoram, wild thyme, and oregano 100% inhibited the growth of all strains. Basil, sage, and anise EOs only partially inhibited the growth of strains. Subsequently, the minimum inhibitory doses were determined using micro-atmospheric method. Minimal inhibition doses were 250 μL/L for thyme and red thyme EO, 250 and 500 μL/L for savory EO, 250 and 500 μL/L for oregano EO, 500 and ˃500 μL/L for wild thyme EO, ˃500 μL/L for caraway and marjoram EOs. Strains of the genus Rhizopus reacted differently to the presence of EOs. Thyme and red thyme were evaluated as the most effective EOs in this study. [ABSTRACT FROM AUTHOR]

Nowadays, it is very important to find out the protection of plant products as an alternative to synthetic fungicides. The promising alternative is the use of the essential oils (EOs). The aim of our research was to evaluate the antifungal effect of angelica (Angelica archangelica L.), anise (Pimpinella anisum L.), fennel (Foeniculum vulgare Miller.), camphore (Cinnamonum camphorum Nees & Eberm), litsea (Litsea deccanensis L.), cumin (Carum carvi L.), dill (Anethum graveolens L.), thyme (Thymus vulgaris L.), mint (citrate) (Mentha citrata L.), mint (piperita) (Mentha piperita L.), laurel (Laurus nobilis L.), cinnamon (Cinnamomum zeylanicum L.) EOs against three isolates of the genus Rhizopus obtained from moldy plants source the chemical composition of selected EOs was determined by gas chromatography coupled with mass spectrometry (GC – MS) and by gas chromatography with flame ionization detector (GC – FID). The antifungal activity of EOs against the growth of Rhizopus spp. was investigated by gas diffusion method (625 μL/L of air). The mycelium growth inhibition was measured on the 2nd, 4th, and 7th days of cultivation. Six EOs: litsea, mint (citrata), mint (piperita), cumin, thyme and cinnamon completely inhibited the growth of all tested fungi. For these EOs the minimum inhibitory doses were determined. According to probit analyses, the most effective tested EO was thyme and the least effective was cumin. Our results indicated that EOs are effective in the vapor phase and had a potential antifungal activity against Rhizopus stolonifer strains. So, they could be utilized in novel biological fungicide development. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the fungicidal effect of eight essential oils against five strains of the genus Rhizopus. Strains were obtained from various moldy foods, namely Rhizopus stolonifer KMi 383 from chestnut, R. stolonifer KMi 510 from strawberry, R. stolonifer KMi 511 from nectarine, R. stolonifer KMi 524 from cherry tomatoes, and R. lyococcus KMi 512 from blackberry. The essential oils (EO) used in this study were jasmine EO (extract from Jasminum officinale L.), bergamot EO (Mentha aquatica L. var. citrata (Her.) Fresen), bitter orange EO (from Citrus aurantium L.), grapefruit EO (Citrus paradisi Macfady), sweet flag EO (East Asian Calamus, from Acorus calamus L. var. angustatus Bes), star anise EO (from Illicium verum J.D.Hook), geranium EO (from Pelargonium graveolens), and lemongrass EO (from Cymbopogon citratus DC). The semi-quantitative composition of the essential oil samples was determined by gas chromatography coupled with mass spectrometry (GC-MS). The antifungal activity of essential oils against the strains of R. stolonifer and R. lyococcus was determined during 7 days, using the micro-atmosphere method (0.625 μL.mL-1 of air). Two essential oils, geranium and lemongrass, completely inhibited the growth of all isolates. Bitter orange essential oil inhibited the growth of all isolates of Rhizopus stolonifer, but isolate of Rhizopus lyococcus began to grow after four days of cultivation. In conclusion, certain essential oils are highly effective in the vapor phase. These could be used in further tests of their antifungal activity and could be used in the control of Rhizopus spp. or other fungal pathogens. [ABSTRACT FROM AUTHOR]