关键词: 小球藻, 油脂, 氮缺失, 热值, 两步培养法

Abstract:

Based on the growth rules of Chlorella pyrenoidosa （ C. pyrenoidosa） and the characteristics of intracellular lipid accumulation in nitrogen-deficient condition, the improvement of lipid content of C. pyrenoidosa using a two-step cultivation method was investigated. The results show that （ 1 ） the optimal mass concentrations of glucose and KNO3 for the high-density cultivation of C. pyrenoidosa are respectively 20 and 1. 50 g/L; （2） with 1.50 g/L KNO3 as the nitrogen source, the biomass of C. pyrenoidosa increases from （7.55 ± 0. 23 ） g/L in the single-step cultivation to （9. 23 ±0. 11 ） g/L in the two-step cultivation; （3） the contents of intracellular lipid and total fatty acids in the two-step cultivation .respectively increase by 5.8% and 5.2% ; and （4） the calorific values improves from （23.58 ±0. 02） kJ/g to （25.52±0.03） kJ/g. It is thus concluded that the two-step cultivation not only results in a high-densitv cultivation of C. pyrenoidosa but also effectively increases the cellular linid content.

Key words: Chlorella pyrenoidosa, lipid, nitrogen deficiency, calorific value, two-step cultivation