Arezoo Hakimi - Department of chemical engineering ,quchan branch, islamic Azad University, quchan, Iran.
Afshin farahbakhsh - Department of chemical engineering ,quchan branch, islamic Azad University, quchan, Iran.
Mohsen parhizkar - Department of chemical engineering ,quchan branch, islamic Azad University, quchan, Iran.

Cheese whey powder (CWP) is an attractive raw material for ethanol production since it is a dried and concentrated form of CW and contains lactose in addition to nitrogen, phosphate and other essentialnutrients. A lactose utilizing yeast strain, Kluyveromyces marxianus DSMZ-7239 was used for ethanolformation from cheese-whey powder (CWP) solution in batch experiments. Effects of initial substrate (CWP) and yeast concentrations on the rate and extent of ethanol formation were investigated. The optimal feed sugar concentration maximizing the ethanol productivity and sugar utilization wasbetween 100 and 125 g l−1 under the specified experimental conditions. the initial sugar concentration should be below 75 g l_1 (CWP < 156 g l_1) and the initial biomass should be above 850 mg l_1 to obtain high rates and yields of ethanol formation and to avoid substrate inhibition

ethanol, Cheese whey powder (CWP), fermentation