Abstract: Surfactant-assisted foam separation process was conducted with a stimulated system using bovine serum albumin (BSA) as targeted protein, and polyoxypropylene polyoxyethylene glylerin ether (PGE) as antifoam agent. The effects of surfactant type (nonionic/ionic), concentration, solution pH and operating factors of G (gas flow rate) and HL (initial liquid pool height) on protein separation efficiency were investigated respectively. The results revealed that nonionic surfactant Tween-20 and ionic SDBS could enhance the system foam capacity and stability, so that the foam process could be operated, while the latter exhibited higher performance and prompted protein adsorption efficiently on the condition the negative charge DBS- attached to BSA with opposite charge via electrostatic force to form a more hydrophobic complex DBS-BSA. And, pH had a strong influence on protein adsorption by affecting the bonding between SDBS and BSA, since the charge distribution of protein molecule surface varied with pH. About 66% of BSA was concentrated in the foamate and the enrichment ratio was 5.34 with initial BSA concentration 0.1 g/L, PGE 4 mg/L, SDBS 50 mg/L, and pH 3.4. A higher BSA recovery rate could be obtained by increasing G or HL, but the enrichment reduced.

Key words: protein, antifoam agent, foam fractionation, adsorption, electrostatic force

摘要： 在以牛血清白蛋白(BSA)为目标蛋白、聚环氧丙烷环氧乙烷甘油醚(PGE)为消泡剂的模拟体系中，考察了表面活性剂种类(非离子型Tween-20和离子型SDBS)、浓度、溶液pH及操作参数(气体流量、初始液池高度)对BSA分离效率的影响. 结果表明，2种活性剂均能改善模拟体系的泡沫性能，使泡沫分离. 后者作用更强并能促进BSA的吸附，因DBS-通过静电作用与带相反电荷的BSA结合形成疏水性更强的BSA-DBS复合物. pH通过影响BSA的电荷分布而影响其与SDBS的结合，进而影响对BSA的吸附，初始BSA浓度0.1 g/L, PGE 4 mg/L, SDBS 50 mg/L, pH为3.4时，约66%蛋白质浓缩在泡沫液中，富集比为5.34. 增加气速或初始液池高度可得到较高收率，但富集比减小.

关键词: 蛋白质, 消泡剂, 泡沫分离, 吸附, 静电结合