氮缺失对蛋白核小球藻（Chlorella pyrenoidosa）的油脂含量的影响以及应用两步培养法提高藻的油脂产率

摘要：氮缺失培养可提高绿藻属Chlorella pyrenoidasa 内的油脂积累并使不同种类的脂肪酸含量也发生改变。两步培养法和氮源KNO3初始浓度为1.5 g/L的单步培养法相比，细胞油脂含量和总脂肪酸含量分别提高了5.8%和 5.2%。两步培养法中生物量浓度为8.32 g/L，而单步培养法中生物量浓度为7.55 g/L。与单步培养法中热焓值为23.587 MJ/kg 相比两步培养法中热焓值提高到25.524 MJ/kg。两步培养法中小球藻热焓值的提高可能是细胞油脂含量提高的缘故。应用两步培养法不但可以提高生物量的浓度而且增加细胞油脂含量。本研究表明，两步培养法特别适合油脂含量丰富的藻的生产，这有利于大规模培养藻生产生物柴油。

Effects of nitrogen deficiency on the lipid content of Chlorella pyrenoidosa and the application of a two-step culture strategy to improving the lipid productivity of the alga

Abstract: Intracellular lipid accumulation in the green alga Chlorella pyrenoidasa was improved in nitrogen-deficient culture which was accompanied by changes of content of different fatty acids. The cellular lipid and total fatty acids contents in the two-step culture were improved by 5.8% and 5.2%, respectively compared to that in the one-step culture with 1.5 g/L KNO3 as nitrogen source. The biomass concentration of 8.32 g/L was achieved in the two-step culture compared to 7.55 g/L in the one-step culture. The calorific value of C. pyrenoidosa was 25.524 MJ/kg in the two-step culture compared to 23.587 MJ/kg in the one-step culture. The higher calorific value in the 2-step culture was perhaps due to the higher cellular lipid content achieved. The application of the two-step culture not only resulted in a higher biomass concentration but also led to a higher cellular lipid content. Results of the present study indicate that the two-step culture strategy is particularly suitable for production of lipid-rich algal biomass which would contribute to the development of large-scale mass production of algae as a source of biodiesel.