右旋糖酐发酵液酶解制备右旋糖酐40中氮的控制  

Control of Nitrogen in Enzymatic Hydrolysis of Dextran Fermentation Broth to Produce Dextran 40

作　　者：问清江[1] 慕娟[1] 孙晓宇[1] 郑巧霞 丁浩[1] WEN Qing-jiang;MU Juan;SUN Xiao-yu;ZHENG Qiao-xia;DING Hao(Shaanxi Inst.of Microbiol.,Xi′an 710043)

机构地区：[1]陕西省微生物研究所,陕西西安710043

出　　处：《微生物学杂志》2022年第5期67-72,共6页Journal of Microbiology

基　　金：陕西省科学院科学研究专项(2020K-06);西安市科技创新人才服务企业项目(2020KJRC0149)。

摘　　要：右旋糖酐发酵液经过吸附除杂和陶瓷膜过滤后处理,在右旋糖酐酶的作用下降解制备右旋糖酐40,对氮进行过程控制,达到右旋糖酐40国家标准。首先以蛋白质作为检测目标,对右旋糖酐发酵液进行吸附条件研究,利用最佳吸附条件进行右旋糖酐发酵液的吸附除杂,氮的去除率达到57%以上,氮含量降至0.09%以下;然后通过陶瓷膜过滤将右旋糖酐与果糖等杂糖分离,并进一步去除氮,氮的去除率达到45%以上,氮含量降至0.040%以下;最后利用右旋糖酐酶对右旋糖酐发酵液处理液进行酶解,右旋糖酐酶解液经过乙醇分级沉淀分离制备右旋糖酐40,氮的去除率达到89%以上,氮含量降至0.003%以下,达到≤0.007%的国家标准。右旋糖酐发酵液酶解制备右旋糖酐40工艺过程氮的控制可以使氮去除率达到98%以上,产品氮含量达到国家标准(≤0.007%),分子量分布有所改善,重均分子量35 000以上,10%小分子>7 000。Dextran 40 was prepared from dextran fermentation broth after adsorption and treated with ceramic membrane filtration under the effect of dextranase degradation, and the nitrogen was conducted process controlled and met the national standard of dextran 40. Firstly, protein was taken as detection target, the adsorption conditions of dextran fermentation broth were studied, and impurity of dextran fermentation broth was implemented with optimized conditions, the removal rate of nitrogen was above 57%, and the content of nitrogen decreased below 0.09%;then adopting ceramic membrane filtration, not only dextran and fructose and miscellaneous sugars were separated, but also nitrogen was further removed. The removal rate of nitrogen was over 45%, and the content of nitrogen decreased below 0.04%. Finally, dextran fermentation broth was treated by dextranase zymolysis, and the dextran zymolysis solution was 40 precipitated and separated adopting ethanol fractional precipitation. The removal rate of nitrogen was above 89%, and the content of nitrogen decreased to under 0.003%. and reached to ≤ 0.007% of national standard. The control of nitrogen in zymolytic process of dextran fermentation broth to prepare dextran 40 could make the removal rate of nitrogen reach above 98% and the content of nitrogen in the product reached the national standard(≤0.007%). The molecular weight distribution had been improved, the weight average molecular weight was above 35 000, and 10% small molecules>7 000.

关 键 词：右旋糖酐 右旋糖酐酶 酶解 氮 陶瓷膜 吸附 

分 类 号：Q935[生物学—微生物学]