盐胁迫下小球藻油脂富集机制研究

发布时间：2018-03-27 07:39

本文选题：小球藻　切入点：盐胁迫　出处：《湘潭大学》2015年硕士论文

【摘要】：利用富油微藻生物质为原料生产生物柴油的研究已经进行了几十年,却只有少量信息是直接或间接地与藻脂类的生物合成的机制相关。因此,揭示脂代谢与环境相互作用机制的调节对提高脂质积累尤其重要。本文采用盐胁迫法异养培养小球藻。论文对盐胁迫下小球藻的油脂含量、产率与异养培养小球藻之间的对比进行了研究,并对钠盐胁迫下的油脂积累机制进行了探讨。主要研究内容和结果如下:1.不同钠盐浓度胁迫培养对小球藻油脂积累的影响小球藻异养培养下,第5天得到最大生物量7.8 g/L。收集到的异养细胞重新接种到含有0.5 mol/L钠离子浓度的新鲜培养基中,12 h过后,得到最大油脂含量53.4%。盐压迫下的最大油脂产率(625.3 mg/L/d)比异养下的高的多(404.6mg/L/d)。2.不同钾盐浓度胁迫培养对小球藻油脂积累的影响小球藻异养培养后,收集到的小球藻细胞重新接入到含有氯化钾的新鲜培养基中,在氯化钾的浓度为0.6 mol/L,胁迫培养12h后,生物指标达到最优结果,即小球藻生物量、脂肪酸含量7.27 g/L,42.9%。与异养下对比,盐压迫下的油脂产率(623.8 mg/L/d)比异养下的高的多(404.6 mg/L/d)。3.不同钠钾盐浓度组合对小球藻油脂积累的影响研究采用响应面分析方法得出的钠钾盐影响小球藻油脂含量积累工艺参数的回归方程为Y=43.22+2.59*A+2.59*B-8.28*A*B-9.98*A*C-7.06*B*C-10.21*C2(A、B、C分别代表钾盐浓度、钠盐浓度、培养时间)。回归系数为1481.55/1537.31=0.945.优化得到的最佳工艺条件为:培养时间15.79h、钾离子浓度0.41 mol/L、钠盐浓度0.52 mol/L,此工艺条件下油脂含量为48.51%,与预测值(48.39%)基本一致(相对误差仅0.24%),该方程拟合实际情况较准确。4.盐胁迫下油脂积累蛋白质组学机理分析通过对具有代表性的富油小球藻普通小球藻研究,揭示了其在NaCl胁迫条件下的油脂代谢调控机制。许多代谢途径,例如,淀粉代谢途径,糖酵解,TCA循环途径,乙醛酸循环途径,脂肪酸合成,TAG代谢途径,蛋白质合成和折叠都和油脂代谢途径直接相关。油脂合成过程是通过许多细胞器的紧密合作来实现的,例如,内质网,线粒体,叶绿体,细胞质基质,等离子体膜。除此之外,转运和调控,ROS防御功能也间接参与到复杂的过程当中。
[Abstract]:The production of biodiesel from oil-rich microalgae biomass has been studied for decades, but only a small amount of information is directly or indirectly related to the mechanism of algal biosynthesis. The regulation of lipid metabolism and environment interaction mechanism is particularly important to increase lipid accumulation. In this paper, the heterotrophic culture of Chlorella vulgaris was carried out under salt stress, and the content of lipid in Chlorella vulgaris under salt stress was studied. The comparison between yield and heterotrophic culture of Chlorella vulgaris was studied. The mechanism of oil accumulation under sodium salt stress was also discussed. The main contents and results were as follows: 1. The effects of different sodium concentration stress on the accumulation of oil and oil in Chlorella vulgaris were studied under heterotrophic culture of Chlorella vulgaris. On the 5th day, the maximum biomass of 7.8g / L. the heterotrophic cells collected were reseeded into a fresh medium containing 0.5 mol/L sodium ion for 12 h. The maximum oil content was 53.4%. The maximum oil yield under salt pressure was 625.3 mg / L / d) higher than that under heterotrophic condition. The effects of different potassium concentrations on the accumulation of oil in Chlorella vulgaris were studied. The collected chlorella cells were re-inserted into the fresh medium containing potassium chloride. When the concentration of potassium chloride was 0.6 mol / L, under stress for 12 h, the biological index reached the optimal result, that is, the biomass of Chlorella vulgaris, the fatty acid content of 7.27 g / L, 42.9%, compared with heterotrophic. The oil yield under salt pressure (623.8 mg / L / d) was higher than that under heterotrophic condition (404.6 mg / L / L / d 路3.Influence of different concentrations of sodium and potassium on oil accumulation of Chlorella vulgaris; response surface analysis method was used to study the effect of sodium and potassium salt on oil accumulation of Chlorella vulgaris. The regress equation of the technical parameters is: Yang 43.22 2.59 A 2.59 B 8.28 AZB 9.98 A C 7.06 C C 10.21 C _ 2 C ~ (2 +) A ~ (2 +) B _ (1) C represent the concentration of potassium salt, respectively. Sodium concentration, The regression coefficient is 1481.55 / 1537.31 / 0.945. The optimum conditions are as follows: culture time 15.79 h, potassium concentration 0.41 mol / L, sodium concentration 0.52 mol / L, and the oil content is 48.51l / L, which is consistent with the predicted value of 48.39% (relative error is only 0.24%). The equation fitted the actual situation more accurately .4.The proteomics mechanism of oil accumulation under salt stress was analyzed through the study of typical Chlorella vulgaris. Many metabolic pathways, such as starch metabolism pathway, glycolytic TCA cycle pathway, glyoxylic acid cycle pathway, fatty acid synthesis pathway, and fatty acid synthesis pathway, were revealed. Protein synthesis and folding are directly related to lipid metabolic pathways. Lipid synthesis is achieved through close cooperation of many organelles, such as endoplasmic reticulum, mitochondria, chloroplast, cytoplasmic matrix, plasma membrane, etc. Ros defense functions are also indirectly involved in complex processes.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE667

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