Background

Fungal morphology and aeration play a significant role in the growth process of Mortierella alpina. The production of microbial oil rich in arachidonic acid (ARA) in M. alpina was enhanced by using a multi-stage fermentation strategy which combined fed-batch culture with precise control of aeration and agitation rates at proper times.

Results

The fermentation period was divided into four stages according to the cultivation characteristics of M. alpina. The dissolved oxygen concentration was well suited for ARA biosynthesis. Moreover, the ultimate dry cell weight (DCW), lipid, and ARA yields obtained using this strategy reached 41.4, 22.2, 13.5 g/L, respectively. The respective values represent 14.8, 25.8, and 7.8% improvements over traditional fed-batch fermentation processes.

Conclusions

This strategy provides promising control insights for the mass production of ARA-rich oil on an industrial scale. Pellet-like fungal morphology was transformed into rice-shaped particles which were beneficial for oxygen transfer and thus highly suitable for biomass accumulation.

中文翻译：

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高山被孢霉生产富含花生四烯酸的微生物油的高效多阶段发酵策略。

 背景

真菌形态和通气在高山被孢霉的生长过程中起着重要作用。通过采用分批补料培养与在适当时间精确控制通气和搅拌速率相结合的多阶段发酵策略，提高了高山M. alpina富含花生四烯酸（ARA）的微生物油的产量。

 结果

根据高山芒草的栽培特点，将发酵期分为四个阶段。溶解氧浓度非常适合ARA生物合成。此外，使用该策略获得的最终细胞干重（DCW）、脂质和ARA产量分别达到41.4、22.2、13.5 g/L。与传统的分批补料发酵工艺相比，各自的值分别提高了 14.8%、25.8% 和 7.8%。

 结论

该策略为工业规模大规模生产富含 ARA 的石油提供了有希望的控制见解。球状真菌形态转变为米状颗粒，有利于氧传输，非常适合生物量积累。