the individual cell counts of yeast and microalga were determined with a haemocytometer using the microscope, due to the appearance of R. glutinis and S. obliquus being totally different under the microscope. Dry biomass was estimated by using the IR-35 moisture analyzer (DENVER) assay; 5ml of whole broth were centrifuged at 7000 rpm for 5 min for the precipitated biomass to be harvested. Then, 1 ml of purify water was put into the tube to achieve complete mixing of aaqueous biomass. The whole aqueous biomass was transferred onto the IR dryer to estimate the dry biomass by water evaporation under infrared radiation. The biomass composition in the co-culture was estimated based on the radio of individual cell weight of each S. obliquus to each R. glutinis, which was about 76/1.