Liu Tingting, Li Pandeng, Ou Ziqi, Feng Yumei, Wang Bohan, Yu Tianyi, Zhu Yuanmin, Yu Longjiang
Department of Biotechnology, College of Life Science and Technology, Institute of Resource Biology and Biotechnology, Huazhong University of Science and Technology, Wuhan, 430074, China.
Key Laboratory of Molecular Biophysics, Ministry of Education, Huazhong University of Science and Technology, Wuhan, 430074, China.
Sci Rep. 2025 May 7;15(1):15967. doi: 10.1038/s41598-025-00965-9.
Solid-state fermentation (SSF), an eco-friendly technology, has shown the high-yield ability to produce products such as biodiesel, pharmaceuticals, and enzymes. However, it has not yet demonstrated an advantage in ARA-containing lipids production. This study demonstrated that agar-supported SSF (AgSF) could induce Mortierella alpina M0223 to yield higher ARA-rich lipids than submerged fermentation (SmF), and elucidated the underlying mechanisms by the comparative transcriptome. AgSF-M0223 formed a mycelial network consisting mainly of surface (SH) and aerial hyphae (AH). The attenuated citrate cycle of SH compared to SmF was coupled with enhanced triglyceride biosynthesis, glycerophospholipid metabolism, and underlying increases in NADPH supply, prompting more glucose flux towards ARA-rich lipid synthesis. Besides, AH has high initial lipid and ARA amounts, while its primary metabolism was weakened due to nutrient scarcity, demonstrating attenuated lipid synthesis. The unique ARA and lipid synthesis characteristics of SH and AH enabled AgSF-M0223 to achieve high-yield ARA-rich lipids. By supplementing nutrients to AH through a spraying strategy and optimizing nutrients for SH, lipid yields reached 12.64 g/L comprising 70.41% ARA, 1.63 times higher than before optimization. These findings provided new insights into fungal physiology under SSF, and presented a promising eco-friendly paradigm for ARA production with advances in mechanical automation.
固态发酵（SSF）是一种环保技术，已显示出在生产生物柴油、药物和酶等产品方面的高产能力。然而，它在含花生四烯酸（ARA）的脂质生产中尚未展现出优势。本研究表明，琼脂支持的固态发酵（AgSF）能够诱导高山被孢霉M0223产生比深层发酵（SmF）更高含量的富含ARA的脂质，并通过比较转录组阐明了其潜在机制。AgSF-M0223形成了一个主要由表面菌丝（SH）和气生菌丝（AH）组成的菌丝网络。与SmF相比，SH中柠檬酸循环的减弱与甘油三酯生物合成、甘油磷脂代谢的增强以及NADPH供应的潜在增加相关联，促使更多的葡萄糖通量流向富含ARA的脂质合成。此外，AH具有较高的初始脂质和ARA含量，但其初级代谢由于营养物质稀缺而减弱，表明脂质合成减弱。SH和AH独特的ARA和脂质合成特性使AgSF-M0223能够实现富含ARA的脂质的高产。通过喷雾策略向AH补充营养物质并为SH优化营养物质，脂质产量达到12.64 g/L，其中ARA含量为70.41%，比优化前高出1.63倍。这些发现为固态发酵条件下的真菌生理学提供了新的见解，并随着机械自动化的进步为ARA生产呈现了一种有前景的环保模式。
