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
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摘要: 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。Abstract: 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 ± 0.12) 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 two-step cultivation could act as another strategy for promoting the lipid accumulation in microalgae.