营养元素和pH对若夫小球藻生长和油脂积累的影响

Effects of trophic elements and pH on growth rate and lipid productivity of Chlorella zofingiensis cells

以若夫小球藻(Chlorella zofingiensis)为研究对象,考察了不同的营养方式(自养、混养、异养),不同的氮源、磷(P)质量浓度和pH对其生长和油脂积累的影响。结果表明,若夫小球藻在混合营养方式下藻体质量浓度及油脂质量分数明显高于自养与异养方式,以蔗糖为碳源的混合营养方式下若夫小球藻总脂质量浓度最高(3.14g.L-1),分别是自养和异养的4.6和5.0倍。以尿素为氮源时若夫小球藻总脂质量浓度最高(0.79 g.L-1)。在一定范围内增加P质量浓度能提高若夫小球藻总脂质量浓度,其最适P质量浓度为7.0～14.0 mg.L-1。人为改变培养液的pH对若夫小球藻细胞生长影响较大,若夫小球藻能够在pH 4.5～9.5范围内生长,超出此范围时细胞很快裂解死亡。

We investigated the biomass productivity and lipid content in Chlorella zofingiensis under different trophic modes （auto- trophic, mixotrophic and heterotrophic ）, with different nitrogen, concentration of phosphorus and pH. The results indicate that the biomass productivity and lipid content of C. zofingiensis under mixotrophic cultivation are higher than that of under autotrophic and heterotrophic cultivation. The lipid productivity of C. zofingiensis is 3.14 g-L^- 1 under mixotrophic cultivation with sucrose, which is 4. 6 and 5. 0 folds of those obtained under autophototropbic and heterotrophic conditions. The maximum lipid productivity is 0. 79 g-L^-1with CONEH4 as nitrogen source. The lipid productivity of C. zofingiensis increases with KEHPO4 concentration at 0 -80 mg-L and optimum concentration of phosphorus is 7.0 - 14. 0 mg-L^-1. In addition, different pH values have great influence on the growth of C. zofingiensis cells, which live in pH from 4. 5 to 9. 5, while die soon when pH exceeds this range.