The pH and OD 600 were measured using a pH meter (EL20, Mettler Toledo, Switzerland) and UV/Vis spectrophotometer (CT- 2200 model, ChromTech Inc., Singapore) at 600 nm, respectively. To translate the OD value into a more comparable value, cell biomass was determined from a standard curve relating OD to dry weight. OD 600 values of 0.5 represented 0.32 mg (dry weight) per ml for yeast strain cells. This relationship was linear up to at least an OD value of 1.0. COD was determined using the closed reflux colorimetric method according to the 508C method in the Stan- dard Methods for the Examination of Water and Wastewater [19] . Reducing sugar was determined using 3,5-Dinitrosalicylic acid as- say (DNS)