Anti fungal Assay of Saccharomyces Cerevisiae HELP
Posted: Sun Mar 24, 2019 5:59 am
Hello,
I am trying to conduct an anti fungal assay of the antifungal properties of several essential oils against baker's yeast, Saccharomyces Cerevisiae. I want to investigate cinnamon oil, lavender oil, and tea tree oil in particular. So far I have been using cinnamon oil for my trial and have tried:
- Using the disk diffusion assay by using Whatman disks soaked in cinnamon oil (just dipped into the container of oil) and this caused complete inhibition of yeast.
- Agar well diffusion assay (making 6mm holes in the agar) with 10, 20, 30, and 40 microlitres placed in 6mm diameter wells. This didn't really work and I saw no inhibition for some reason (does oil not diffuse well in agar?)
Now I'm wondering:
- Should I use different amounts in microlitres (20, 30, etc) of the oil and just load them on each disk and see if there are results?
- Should I make a solution where I have maybe 20 microlitres with 30 microlitres of solvent and load that in the disk. i.e, do the disks have to be soaked to work, or is the small amount of oil on its own enough?
- If I use a solvent, which one should I use? I know ethanol can dissolve the oil but will this be an interfering variable since ethanol is toxic at high levels to yeast? I used ethanol in another experiment where I dissolved cinnamon powder and loaded the disks with that and I saw clear zones of inhibition, should I worry that this is due to ethanol rather than cinnamon powder?
- If not ethanol, what other cheap and available solvents can I use?
I am trying to conduct an anti fungal assay of the antifungal properties of several essential oils against baker's yeast, Saccharomyces Cerevisiae. I want to investigate cinnamon oil, lavender oil, and tea tree oil in particular. So far I have been using cinnamon oil for my trial and have tried:
- Using the disk diffusion assay by using Whatman disks soaked in cinnamon oil (just dipped into the container of oil) and this caused complete inhibition of yeast.
- Agar well diffusion assay (making 6mm holes in the agar) with 10, 20, 30, and 40 microlitres placed in 6mm diameter wells. This didn't really work and I saw no inhibition for some reason (does oil not diffuse well in agar?)
Now I'm wondering:
- Should I use different amounts in microlitres (20, 30, etc) of the oil and just load them on each disk and see if there are results?
- Should I make a solution where I have maybe 20 microlitres with 30 microlitres of solvent and load that in the disk. i.e, do the disks have to be soaked to work, or is the small amount of oil on its own enough?
- If I use a solvent, which one should I use? I know ethanol can dissolve the oil but will this be an interfering variable since ethanol is toxic at high levels to yeast? I used ethanol in another experiment where I dissolved cinnamon powder and loaded the disks with that and I saw clear zones of inhibition, should I worry that this is due to ethanol rather than cinnamon powder?
- If not ethanol, what other cheap and available solvents can I use?