To detect their alcohol producing ability, quantitative estimation of ethanol by
potassium dichromate method13 was followed. The supernatant (1 mL) of centrifuged culture
broth of glucose-grown yeast strain was made up the volume to 5 mL with distilled water.
Then 1 mL of Potassium dichromate reagent was added. All the test tubes were kept in ice
water and 4 mL of conc. sulfuric acid added to each tube gently through the walls. Then the
optical density was measured at 660 nm. Alcohol standard was prepared by dissolving
absolute ethanol in water to get 10 mg/mL concentration.K2Cr2O7 solution was prepared by
dissolving 10 gm of K2Cr2O7 in distilled water in a 100 ml standard flask and make up the
volume to mark.