蛋白核小球藻发酵产油脂的研究

Study on Microbial Oil Production with Chlorella pyrenoidosa

摘要:

从5种不同来源的小球藻中筛选到1株油脂产量较高的蛋白核小球藻Chlorella pyrenoidosa No.2。研究了培养基组成及培养条件对其细胞生长和油脂积累的影响。结果表明, 最适培养基组成为(g/L)：葡萄糖 20, 甘氨酸 0.08, MgSO4·7H2O 0.4, K2HPO4 1.0, FeSO4·7H2O 0.004; 适宜的培养温度、初始pH、摇床转速和光照强度分别为28℃、6.0、130 r/min和 650 Lux。在上述优化条件下培养7 d, Chlorella pyrenoidosa No.2的生物量和油脂含量分别由优化前的3.73 g/L 和 40.15%提高到6.56 g/L和59.90%, 油脂产量提高了162%。Chlorella pyrenoidosa No.2能以木糖为碳源产油脂, 可望用于以木质纤维素等可再生生物质资源为原料生产油脂。气相色谱分析表明该油脂的脂肪酸组成与植物油相似, 不饱和脂肪酸含量达71％左右, 可作为生产生物柴油的原料。

Abstract:

Chlorella pyrenoidosa No.2 was screened from five species of microalga Chlorella sp. for its higher lipid yield. Effects of medium components and culture conditions on cell growth as well as lipid accumulation of C. pyrenoidosa No.2 were investigated and the results showed that the optimum medium recipe was 20.0 g/L glucose, 0.08 g/L glycine, 1.0 g/L K2HPO4·3H2O, 0.4 g/L MgSO4·7H2O and 0.004 g/L FeSO4·7H2O. The optimum culture temperature, initial pH, shaking rate and light intensity were 28℃, 6.0, 130 r/min and 650 Lux, respectively. Biomass and lipid content increased from 3.73 g/L and 40.15% to 6.56 g/L and 59.90% when Chlorella pyrenoidosa No.2 was cultivated under the above optimal conditions for 7 days, with lipid yield raised by 162%. Chlorella pyrenoidosa No.2 could produce lipid with xylose as carbon source, and so is potential for lipid production from renewable materials such as lignocellulose. GC analysis demonstrated that the fatty acid composition of the lipid was similar to that of vegetable oil and its unsaturated fatty acid content reached around 71%, thus it is a promising material for biodiesel production.