Harvesting and Separation Technique of Porphyridium cruentum Polysaccharide Using Ultrafiltration Membrane

Red microalga Porphyridium cruentum secreting polysaccharides into its medium culture. Harvesting and separation of polysaccharide of P. cruentum usually use centrifugation and in large scale needs high cost. The use of ultrafiltration membrane can be one of the alternatives for harvesting and separation of P. cruentum polysaccharide. This study aimed to determine the characteristic of membrane and permeat from harvesting and separation of P. cruentum polysaccharide using ultrafiltration. Research consisted of four stages : membrane characterization, cultivation of P. cruentum, harvesting using 0.05 μm ultrafiltration membrane, and polysaccharide separation using 0.01 μm ultrafiltration membrane. Characterization of membrane permeability and internal resistance on ultrafiltration 0.05 μm dan 0.01 μm were 137.32 L/m2hbar and 62.38 L/m2hbar and 0.01 barm2h/L and 0.02 barm2h/L, respectively. Harvesting using ultrafiltration 0.05 μm produced flux 131.37-94.75 L/m2h, biomass rejection 96% and permeate with OD (Optical Density) (0.01 ± 0.00), viscosity (2.4 ± 0.17 cp), pH (8 ± 0.00), and salinity (42.37 ± 0.11 ‰). Separation of polysaccharide using ultrafiltration 0.05 μm produced flux 58.11-51.53 L/m2h and permeate with viscosity (2.2 ± 0.30 cp), pH (7.8 ± 0.01), and salinity (38.73 ± 0.05 ‰). Ultrafiltration process decreased OD, viscosity, and salinity of permeate.