Rao Xiaolan, Liang Wensheng, Jing Xin, Liu Chang, Li Jiahong, Liu Limei, Gao Xiang
State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan 430062, China.
College of Food Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
Synth Syst Biotechnol. 2025 Jun 14;10(4):1160-1171. doi: 10.1016/j.synbio.2025.06.004. eCollection 2025 Dec.
Microalgae surviving in extreme conditions evolve tolerance mechanisms to diverse environmental stresses. Environmental nitrogen limitation or nitrogen starvation poses a significant threat to the growth of microalgae, but it is an effective factor in inducing lipid accumulation in many microalgal species. In this study, we report the genome sequence of a promising oil-producing strain, sp. WL1, which is capable of resisting long-term nitrogen starvation and responds rapidly to nitrogen recovery. Its genome comprises 127 Mb of nuclear DNA and 17,392 protein-coding genes. Comparative genomic and transcriptomic analyses identified a group of genes involved in nitrate metabolism and lipid accumulation. Heterologous expression of three candidate genes in the model cyanobacterium sp. PCC 6803 demonstrated their effects on restoring the cellular chlorophyll upon nitrogen recovery. Our results provide novel insights into the molecular basis of metabolic shifts in response to nitrogen starvation and recovery in microalgae.
在极端条件下生存的微藻会进化出应对各种环境压力的耐受机制。环境中的氮限制或氮饥饿对微藻的生长构成重大威胁，但却是诱导许多微藻物种脂质积累的一个有效因素。在本研究中，我们报告了一种有前景的产油菌株—— sp. WL1的基因组序列，该菌株能够抵抗长期的氮饥饿，并对氮恢复迅速做出反应。其基因组包含127 Mb的核DNA和17392个蛋白质编码基因。比较基因组学和转录组学分析确定了一组参与硝酸盐代谢和脂质积累的基因。在模式蓝藻sp. PCC 6803中对三个候选基因进行异源表达，证明了它们在氮恢复时对恢复细胞叶绿素的作用。我们的结果为微藻响应氮饥饿和恢复时代谢转变的分子基础提供了新的见解。
