利用外源γ-氨基丁酸调控海洋绿藻亚心形四爿藻淀粉积累  

Regulation of starch accumulation by exogenous gamma-aminobutyric acid in marine green microalga Tetraselmis subcordiformis

作　　者：冉雯仪 项琦 潘云云 姚长洪 张永奎[1] RAN Wenyi;XIANG Qi;PAN Yunyun;YAO Changhong;ZHANG Yongkui(School of Chemical Engineering,Sichuan University,Chengdu,Sichuan 610065)

机构地区：[1]四川大学化学工程学院,四川成都610065

出　　处：《工业微生物》2020年第2期48-54,共7页Industrial Microbiology

基　　金：中央高校基础研究基金(YJ201734);四川大学大学生创新创业训练计划(C2019107170);国家自然科学基金(41406177)。

摘　　要：微藻被看作第三代生物质能源的来源。微藻淀粉结构与高等植物的高度相似性使其可以作为粮食作物的替代,在生物能源领域有广泛的应用。γ-氨基丁酸(GABA)被认为是一种信号分子,可以调节植物细胞的生长代谢。本研究在缺氮培养条件下添加外源GABA调控海洋绿藻亚心形四爿藻生理代谢和淀粉积累。结果表明,添加外源GABA可以抑制细胞生长,降低光合作用效率;OJIP实验显示,GABA的添加增强了光合器官能量耗散,降低了光能利用效率,阻碍了电子传递,造成额外胁迫,从而促使细胞将碳流更多地分配到淀粉积累,导致藻细胞的淀粉含量、淀粉产量和淀粉产率提高。添加10 mmol/L GABA获得最大淀粉含量39%DW,比未添加GABA的对照组淀粉含量提高39%;同时获得最大淀粉产量和产率为1.72 g·L^-1和0.36 g·L^-1·d^-1,分别比未添加GABA的对照组提高39%和50%。以上结果表明在缺氮条件下添加外源GABA是一种调控亚心形四爿藻细胞代谢并提高其淀粉生产的有效方法。Microalgae are regarded as a source for third-generation biofuels.The structure of microalgae starch is similar to that of higher plants,so it can be used as a substitute for food crops and widely used in the field of bioenergy.Gamma-aminobutyric acid(GABA)is considered to be a signal molecule that can regulate the growth and metabolism of plant cells.In this study,exogenous GABA was added to regulate the physiological metabolism and starch accumulation of marine green microalga Tetraselmis subcordiformis in nitrogen-deficient culture.The results showed that exogenous GABA could inhibit cell growth and reduce photosynthetic efficiency.The OJIP test showed that the addition of GABA enhanced the energy dissipation of photosynthetic apparatus,reduced the light energy utilization efficiency,blocked the electron transfer and caused additional stress,thus induced cells to allocate more carbon flow to starch accumulation and resulted in higher starch content,starch yield and starch productivity.The maximum starch content was 39%DW by adding 10 mmol/L of GABA,which was 39%higher than that of the control group without GABA.At the same time,the maximum starch yield and productivity were 1.72 g·L^-1 and 0.36 g·L^-1·d^-1,which showed 39%and 50%improvements compared with those of the control group without GABA,respectively.The above results indicated that adding exogenous GABA under the condition of nitrogen deficiency was an effective method to regulate the cell metabolism of Tetraselmis subcordiformis and improve the starch production.

关 键 词：亚心形四爿藻 缺氮 淀粉 Γ-氨基丁酸 

分 类 号：TS2[轻工技术与工程—食品科学与工程]