Screening Of Exopolysaccharide-Producing Strain From Marine Bacterial And Fermentation Kinetics Study

Masses of marine microorganisms were screened. One bacterial which can produce sulfated exopolysaccharides were gained. The medium and fermentation conditions were optimized.This paper studied such factors as carbon source, nitrogen source and their concentration, temperature, pH, shaking speed, salinity, inoculums size , and so on. By study of fermentation technology, the optimized medium consisted of: sucrose 4%, (NH₄)₂SO₂ 0.4%, artificial seawater, NaCl 5%, PH 8.0.The best culture conditions: 500mL conical flask containing 200mL liquid medium, 8% inoculums size, 31℃, shaking speed should be 200r/min, 7days on a rotary shaker. Under the optimized conditions, the yield of polysaccharides can reach 8g/L.The fermentation kinetic parameters of biomass, polysaccharide and sucrose consumption by M4 were calculated by applying the Logistic, the Luedeking-Piret equation respectively. By comparing the experimental data with the models, three models were testified and could describe the fermentation course well.