双酶协同水解木薯淀粉水解液对小球藻生物量和油脂积累的影响  

Effect of Cassava Starch Hydrolysate by Two Enzymes on Cell Biomass and Lipid Accumulation of Chlorella protothecoides

作　　者：李玉芹[1] 袁正求[1] 冯岳[1] 黎萍[1] 周蒙[1] 姚威[1] 张剑[1] 

机构地区：[1]湘潭大学化工学院,湖南湘潭411105

出　　处：《中国生物制品学杂志》2011年第7期794-796,共3页Chinese Journal of Biologicals

基　　金：湘潭大学自然科学基金项目(09XZX11);2010年度湖南省大学生研究性学习和创新性实验计划立项资助;博士科研启动项目(09QDZ24);湖南省教育厅项目(10C1274)

摘　　要：目的以木薯淀粉水解液替代葡萄糖异养培养小球藻,观察其对小球藻生物量和油脂积累的影响。方法采用双酶协同酶解法水解木薯淀粉,扫描电镜和X-射线衍射表征分析水解前后产物的物理特性;分别以精制葡萄糖和木薯淀粉水解液作为碳源,尿素作为氮源,采用异养模式培养小球藻;干重法测定藻细胞生物量,提取总脂,气相色谱-质谱联用技术(GC-MS)分析脂肪酸含量。结果双酶协同水解木薯淀粉的最佳工艺条件为:温度70℃,pH 4.0,时间3 h,酶添加量0.5%,底物浓度20 g/L,此时水解木薯淀粉转化成的葡萄糖含量为64.11%;表征分析显示,酶解发生在颗粒表面,整个淀粉颗粒仍能保持外形结构,酶水解作用未改变木薯淀粉的晶型;当培养基中葡萄糖浓度为40 g/L时,小球藻生物量和总脂产量分别为9.12和4.39 g/L;当培养基中木薯淀粉水解液的葡萄糖浓度为30 g/L时,小球藻生物量和总脂产量分别为9.50和4.51 g/L,比以葡萄糖为碳源时的生物量和总脂产量高4.17%和2.73%。结论木薯淀粉水解液作为碳源在异养培养提高微藻油脂产量和减少微藻生物柴油生产成本方面是一种比较理想的途径。Objective To observe the effect of cassava starch hydrolysate（CSH） used as a carbon source instead of glucose on cell biomass and lipid accumulation of Chlorella protothecoides.Methods Cassava starch was hydrolyzed with two enzymes,and analyzed for physical characteristics before and after hydrolysis by scanning electron microscopy（SEM） and X-ray diffraction.C.protothecoides were cultured by heterotrophic mode using purified glucose and CSH as carbon sources respectively and urea as a nitrogen source,and determined for biomass by loss on drying,from which total lipid was extracted and analyzed for fatty acid content by gas chromatography-mass spectrometry（GC-MS）.Results The optimal temperature,pH value,time,enzyme dosage and substrate concentration for hydrolysis of cassava starch with two enzyme were 70℃,4.0,3 h,0.5% and 20 g/L respectively.Under the optimal condition,the content of glucose transformed from CSH was 64.11%.SEM and XRD showed hydrolysis only on the surface of starch particles,without destruction of crystal structure of cassava starch.The biomass and total lipid content of C.protothecoides cultured in the medium containing 40 g/L glucose were 9.12 and 4.39 g/L respectively.However,when the CSH at a glucose concentration of 30 g/L was used as a carbon source,the biomass and total lipid content were 9.50 and 4.51 g/L,which increased by 4.17% and 2.73% as compared with those using glucose as a carbon source respectively.Conclusion CSH is an ideal route to increase the lipid output of microalgae in heterotrophic culture and decrease the production cost of biodiesel.

关 键 词：木薯属 淀粉 葡萄糖 小球藻属 生物量 油脂 

分 类 号：TK6[动力工程及工程热物理—生物能]