【作者】 孙珊；

【导师】 田黎；

【作者基本信息】 青岛科技大学 ， 发酵工程， 2009， 硕士

【摘要】 随着人口增长与自然资源短缺的矛盾日益尖锐,油脂与人类的关系越来越密切,无论是作为生物柴油的原料还是加工成为保健食品,油脂都具有至关重要的作用。目前,传统的油脂来源动物脂肪与植物油脂已经不能完全满足人们的食用、工业等生活中的各种需求,因此寻找一种成本低、来源广以及成分好的油脂原料成为亟待解决的问题。而利用微藻为原料生产油脂具有无可比拟的优势。大量研究表明,微藻油脂的含量随微藻种类的不同有较大差异,且微藻油脂含量及组成会因环境因素的差异而产生变化。本文首先通过比较比较冻融法、研磨法、乙醚-石油醚法、氯仿-甲醇法和酸热法5种方法对4类微藻的油脂提取率发现:细胞破碎方法与不同有机溶剂的组合对油脂提取率有较大影响,确定冻融法为从多株微藻中筛选富油微藻的最佳油脂提取方法。利用冻融法对十余株微藻进行筛选,筛选出金藻（Isochrysis sp.）、前沟藻（Amphidiniu sp.）、异湾藻（Heterosigma sp.）和原甲藻（Prorocentrum sp.）等4株富油微藻,其粗脂含量分别为45%、36.7%、35%和29.5%;对筛选出的4株富油微藻的生长特性和油脂产率进行研究,并利用气相色谱对脂肪酸组成进行分析,发现4株微藻油脂产率分别为5.58 mg·d^-1·L^-1、7.57mg·d^-1·L^-1、7.44mg·d^-1·L^-1和8.36 mg·d^-1·L^-1,所产脂肪酸C16-C18系的含量均占脂肪酸总量的68%以上,从分子结构上分析符合制备生物柴油的要求。前沟藻EPA的含量高达24.95%,可对其优化培育,制备EPA应用于医疗和保健品中。最后以含油量最高的金藻为研究对象,研究培养液中不同浓度的氮、磷、硅对其油脂含量的影响。发现氮源不足会对金藻的生长产生抑制,但是会增加其油脂含量,在NaNO₃浓度为150μM、600μM和3000μM时,金藻的油脂含量分别为63.4%、47.3%和20.5%。油脂产率以NaNO3浓度为600μM时最高,为63.4mg·L^-1;金藻平台期收获时的生物量随者磷源浓度的升高而增高,油脂含量变化随磷浓度的增高呈相反趋势,在NaH₂PO₄浓度为6μM、25μM和36μM时,金藻的油脂含量分别为55.1%、40.5%和37.8%。油脂产率的变化趋势与油脂含量相反,以NaH₂PO₄浓度为36μM时最高,为64.3mg·L^-1;硅对金藻平台期收获时的生物量没有较大影响,油脂含量及油脂产率均在没有硅的情况下较高,分别为37.8%及42.2 mg·L^-1。更多还原

【Abstract】 With the population increasing and scarcity of the natural resource, people have to find a renewable, biodegradable, and non-toxic fuel to replace the fossil fuel. The conventional oil resource such as plant lipids and anminal fat can not satisfy people’s demand, so finding a new kind of oil raw material is very important. Microalgae is one kind of the important raw materials due to the advantages such as high contents of lipids and the unoccupation of plantation.The contents of lipids of microalgae are different according to different kinds of microalgae and affected by various environmental factors. In this study, a high efficiency, easy and suitable method of lipids exacting was found by comparing different kinds of exacting methods. The rich lipids-microalgae were found out through determining the total fat contents of 12 strains of microalgae and the lipid yields were calculated according to the growth cycle and biomass. In addition, fatty acid composition of four microalgae were determined by GC-MS. The results showed that: 1)Isochrysis sp., Amphidinium sp., Heterosigma sp. and Prorocentrum sp. were rich lipids-microalgae with the total lipid content accounting for 45%、36.5%、35% and 29.5% of the total cells dry weight respectively. 2)Biomass was one of the important factors which affected the lipid yields and the lipid yields of four rich lipids-microalgae were 5.58 mg·d^-1·L^-1、7.57mg·d^-1·L^-1、7.44mg·d^-1·L^-1 and 8.36 mg·d^-1·L^-1 respectively. 3)The major fatty acids in four rich lipids-microalgae were C16-C18（more than 68% of total fatty acid）. From the results, they were fit for chemical composition of biodiesel.The influence of nitrogen,phosphorus,and silicon nutrition on the growth rate and lipid content of Isochrysis sp. was studied by single factor experiment. The results showed that Isochrysis sp. grew slowly in low level of nitrogen,phosphorus nutrition but the content of oils was high. When the NaNO3 levels were 150μM, 600μM and 3000μM,the lipid contents were 63.4%、47.3% and 20.5% respectively and the highest lipid yield was 63.4mg·L^-1 in the 600μM level. When the NaH2PO4 levels were 6μM, 25μM and 36μM,the lipid contents were 55.1%、40.5% and 37.8% respectively and the highest lipid yield was 64.3mg·L^-1 in the 36μM level. Silicon nutrition did not affect much on the Isochrysis sp. growth, and the lipid content and lipid yield were 37.8% and 42.2mg·L^-1 with silicon which were higher than silicon scarcity.更多还原