摘要
为明确微藻油脂与淀粉代谢过程中是否存在相互竞争与转化关系,以微藻Ankistrodesmus sp.HJ12为实验材料,对不同氮浓度培养条件下的微藻Ankistrodesmus sp.HJ12生物量、油脂含量和淀粉含量进行测定,并进行比较转录组研究,探讨其油脂和淀粉积累相关影响及分子调控机制。结果表明:氮浓度对该藻株油脂和淀粉积累具有显著影响,且油脂与淀粉积累呈显著负相关关系;培养基中添加氮源时,微藻Ankistrodesmus sp.HJ12油脂含量显著高于无氮源条件,油脂含量最高时的氮浓度为7.6 mmol/L;无氮源时,其淀粉含量最高;比较转录组研究发现,促进微藻Ankistrodesmus sp.HJ12油脂积累的主要因素可能是脂肪酸合成途径、糖酵解途径与淀粉分解代谢途径的增强,为脂肪酸的合成提供了更多的乙酰-CoA和碳源,从而促进了脂肪酸的合成;挖掘得到4个调控脂质合成代谢的关键基因ACACA、α-AMY、PDC和adh,采用实时荧光定量PCR(RT-qPCR)验证基因表达差异变化,结果与转录组分析差异一致。研究结果可为进一步了解微藻脂质合成代谢的分子机制提供一定的参考,同时为加快微藻油脂制备生物柴油实现规模化应用增添新的有利基础。
In order to clarify the relationship of lipid and starch metabolism in microalgae, with Ankistrodesmus sp. HJ12 as the experimental material, its biomass, lipid contents and starch contents were measured under different nitrogen concentrations, and comparative transcriptome were studied. The correlation between microalgae lipid and starch accumulation was explored and their molecular regulation mechanisms were investigated. The results showed that nitrogen concentration remarkedly influenced lipid and starch accumulation in Ankistrodesmus sp. HJ12, and there was a negative correlation between them. The lipid contents of algal cells cultured in media with nitrogen were significantly higher than those in nitrogen-free media. The optimal nitrogen concentration for lipid accumulation was 7.6 mmol/L. In contrast, the starch contents of algal cells were the highest in nitrogen-free media. Comparative transcriptome analysis showed that genes involved in fatty acid synthesis, glycolytic and amylolytic pathway were expressed at higher levels in Ankistrodesmus sp. HJ12 than the control, implying that the cells accumulated more acetyl-CoA and carbon source for fatty acid synthesis under nitrogen limitation, and promoting the synthesis of fatty acids. Moreover, four key genes of regulating lipids anabolism, ACACA, α-AMY, PDC and adh, were selected for RT-qPCR analysis, and the results of gene expression partterns were in consistent with those obtain by transcriptome analysis. The results of the study provided a basis to deeply understand the molecular mechanism of microalgae lipids anabolism. In addition, it added a new favorable foundation for accelerating producing biodiesel from microalgae lipids to achieve large-scale applications.
作者
林伟泽
马帅
李亚军
张家明
谭德冠
邓茹茹
刘平怀
LIN Weize;MA Shuai;LI Yajun;ZHANG Jiaming;TAN Deguan;DENG Ruru;LIU Pinghuai(School of Chemical Engineering and Technology,Hainan University,Haikou 570228,China;Hainan Key Laboratory of Tropical Microbe Resources,Hainan Academy of Tropical Agricultural Resources of Chinese Academy of Tropical Agricultural Sciences(CATAS),Institute of Tropical Bioscience and Biotechnology of CATAS,Haikou 571101,China)
出处
《中国油脂》
CAS
CSCD
北大核心
2023年第1期137-145,共9页
China Oils and Fats
基金
中国热带农业科学院基本科研业务费创新团队项目(1630052020020)
国家重点研发计划资助项目(2021YFA0909600)
海南省自然科学基金项目(321MS083)。
关键词
微藻
油脂
淀粉
转录组
分子调控机制
microalgae
lipid
starch
transcriptome
molecular regulation mechanism
