Hi Syarief Abdullah Shofi

I did this experiment for my yeast isolates using two methods. One was conducted in broth culture and the other set in yeast extracts peptone agar plates supplemented with different series of glucose. The glucose tolerance or osmotolerance of yeast isolates was evaluated by individually inoculating them in triplicate into a series of tubes containing 5 mL of Yeast extract peptone broth with varying glucose concentrations (2%, 5%, 10%, 20%, 30%, 40%, and 50% w/v). The tubes were incubated at 37°C for 24 h. Then the absorbance was measured at 540 nm using UV visible spectrophotometry. Plotting absorbance vs glucose concentration showed the glucose tolerance level of yeast. Then the yeast extract peptone agar plates with the same glucose concentrations were prepared and 100 microlitres of yeast suspension were spread inoculated into the plate surface. .In the plates with higher osmotic pressure caused by glucose the yeast colonies did not appear. For my yeast isolates, they did not grow when the plates had above 10% glucose. I think you can try some experiment likewise.

Hi,

see the attached file.

Glucose Agar with 25% Glucose

Composition per liter:

Glucose ..................................................................................... 250.0g

Agar ............................................................................................ 25.0g

Polypeptone™.............................................................................. 5.0g

Malt extract................................................................................... 3.0g

Yeast extract.................................................................................. 3.0g

Preparation of Medium: Add components to distilled/deionized

water and bring volume to 1.0L. Mix thoroughly. Gently heat and bring

to boiling. Distribute into tubes or flasks. Autoclave for 15 min at 15

psi pressure–121°C. Pour into sterile Petri dishes or leave in tubes.

Use: For the cultivation and maintenance of osmophilic yeasts and

bacteria.