甜菜碱对单针藻Monoraphidium sp.QLY-1油脂积累的影响

Effects of glycine betaine on lipid accumulation of Monoraphidium sp.QLY-1

为提高单针藻Monoraphidium sp.QLY-1的生物量和油脂产量,本文结合两阶段策略,即异养-光诱导培养方法,研究甜菜碱(GB)对单针藻QLY-1生长和油脂积累的影响。结果表明,异养、自养的微藻生物量分别为(5.54±0.22)、(0.878±0.12)g/L,且异养比自养提高了5.3倍。此外,在光胁迫下,添加5 mmol/L甜菜碱时可有效提高微藻的油脂含量,其油脂含量(47.37%±2.93%)相比对照(36.68%±1.34%)提高了0.29倍(p<0.05)。进一步的研究表明,与对照相比,添加5 mmol/L甜菜碱时,藻细胞中性脂增加了12.83%±0.75%,对藻细胞内脂肪酸组成无显著性影响。研究表明,甜菜碱作为一种外源诱导子可有效促进微藻细胞中油脂积累,甜菜碱结合两阶段法可作为促进微藻细胞油脂积累的另一策略。

For promoting biomass and lipid production in Monoraphidium sp.QLY-1, this study investigated that the effects of glycine betaine （GB） on the growth and lipid accumulation in QLY-1 in combination with a two-step strategy, which was called heterotrophic and photoinduction cultivation. Results showed that the biomass concentration of heterotrophic and autotrophic algal cells were （5.54 ＋ 0.22） and （0.878 ＋ O. 12） g/L, respectively, and the heterotrophic cells was 5.3 folds higher than that of the autotrophic.Moreover, under high light stress, the lipid content （47.37% ± 2.93% ）was enhanced by 0.29 folds （p 〈 0.05 ） treated with 5 mmol/L glycine betaine than that of control（ 36.68%± 1.34% ）.Further studies showed that the neutral lipid content was increased to 12.83% ± 0.75% than that of the control, and was no significant influences on the fatty acids composition under 5 mmol/L glycine betaine induction.The results indicated that glycine betaine could significantly increase the production of lipid in microalgae, combination of glycine betaine and twostep cultivation could act as another strategy for promoting the lipid accumulation in microalgae.