Abstract
An extracellular polysaccharide(EPS) producing bacteria,named BIT-BP004,was isolated from oil/water sample of Liaohe oilfield.The optimal medium compositions in shake scale for strain BIT-BP004 were determined as follows: sucrose 7.5 g/L,NaNO3 0.5 g/L,K2HPO4 1.5 g/L,KH2PO4 3 g/L,MgSO4 0.1 g/L,CaCl2 0.01 g/L,initial pH 6 and inoculant’s volume 1%.The EPS yield was 4.11 g/L in batch culture after 24 h.By orthogonal design,the factors of temperature,mineral salt concentration and pH value were selected to assay the physico-chemical property of fermentation.The results showed that experiment factors had a larger effect on viscosity of fermentation,and the affection capacity was arranged as follows,temperature > mineral salt concentration > pH,indicating that temperature was a decisive factor on the viscosity of the fermentation broth.