针对Paenibacillus polymyxa ZJ-9一步法发酵菊芋菊粉粗提液制备R,R-2,3-丁二醇的发酵液特点,利用壳聚糖对该发酵液进行絮凝研究。结果表明,壳聚糖分子量、壳聚糖用量、助凝剂海藻酸钠用量、pH和搅拌时间分别为:43.5 kDa、0.75 g/L、0.125 g/L、5.0和15 min时,絮凝效果最佳,在此工艺条件下,发酵液中菌体和蛋白质的絮凝率分别高达89.46%和78.93%,而R,R-2,3-丁二醇保留率约为98.54%。利用双水相萃取技术对絮凝后的发酵液中R,R-2,3-丁二醇进行了分离,结果表明,异丙醇/硫酸铵双水相体系萃取效果最好,当异丙醇和硫酸铵的用量分别约为33%和30%(w/w)时,R,R-2,3-丁二醇在上相的分配系数和萃取率最高,分别约为7.96和89.40%,且异丙醇/硫酸铵双水相体系能够有效萃取分离絮凝后的发酵液中不同含量的R,R-2,3-丁二醇。絮凝和双水相萃取技术分离发酵液中R,R-2,3-丁二醇具有针对性强、效率高、成本低等优点,适用于工业化生产。

R,R-2,3-Butanediol(R,R-2,3-BD) can been produced through one-step fermentation of inulin extract from Jerusalem artichoke tubers using Paenibacillus polymyxa ZJ-9.The pretreatment of fermentation broth by chitosan flocculation was investigated.The results were as following:the optimum flocculation was obtained using 0.75 g/L of chitosan with 43.5 ku molecular weight,0.125 g/L of sodium alginate,pH 5.0 and stirring for 15 minutes.The flocculation rate of cells and proteins reached 89.46% and 78.93%,respectively,and the retained ratio of R,R-2,3-butanediol reached 98.54%.Then,the different aqueous two-phase extraction systems were used to further investigate extraction of R,R-2,3-BD from the pretreated fermentation broth and the isopropanol/ammonium sulphate system was chosen as optimum system.The optimum phase composition was 33%(w/w) of isopropanol and 30.0%(w/w) of ammonium sulphate,and the partition coefficient and recovery of R,R-2,3-BD reached 7.96 and 89.40%,respectively.Furthermore,the isopropanol/ammonium sulphate aqueous two-phase extraction system could be used to separate different concentration R,R-2,3-BD from the pretreated fermentation broth by chitosan flocculation.