Rewiring metabolic network by chemical modulator based laboratory evolution doubles lipid production in Crypthecodinium cohnii

• Published in: Metabolic engineering 2019-01, Vol.51, p.88-98
• Main Authors: Diao, Jinjin, Song, Xinyu, Cui, Jinyu, Liu, Liangsen, Shi, Mengliang, Wang, Fangzhong, Zhang, Weiwen
• Format: Article
• Language: English
• Subjects: Acetyl-CoA Carboxylase - metabolism; Benzodioxoles - pharmacology; Biomass; C. cohnii; Carbon - metabolism; Carbon relocation; Cell growth; CM-ALE; Cyclohexanones - pharmacology; Dinoflagellida - metabolism; Directed Molecular Evolution - methods; Docosahexaenoic Acids - biosynthesis; Lipid; Lipids - biosynthesis; Malonyl Coenzyme A - metabolism; Metabolic Networks and Pathways - drug effects; Metabolic Networks and Pathways - genetics; Phenols - pharmacology; Reactive Oxygen Species - metabolism; Starch - metabolism
• ISSN: 1096-7176; 1096-7184
• DOI: 10.1016/j.ymben.2018.10.004

Dietary omega-3 long-chain polyunsaturated fatty acids docosahexaenoic acid (DHA, C22:6) can be synthesized in microalgae Crypthecodinium cohnii; however, its productivity is still low. Here, we established a new protocol termed as “chemical modulator based adaptive laboratory evolution” (CM-ALE) to enhance lipid and DHA productivity in C. cohnii. First, ACCase inhibitor sethoxydim based CM-ALE was applied to redirect carbon equivalents from starch to lipid. Second, CM-ALE using growth modulator sesamol as selection pressure was conducted to relive negative effects of sesamol on lipid biosynthesis in C. cohnii, which allows enhancement of biomass productivity by 30% without decreasing lipid content when sesamol was added. After two-step CM-ALE, the lipid and DHA productivity in C. cohnii was respectively doubled to a level of 0.046 g/L/h and 0.025 g/L/h in culture with addition of 1 mM sesamol, demonstrating that this two-step CM-ALE could be a valuable approach to maximize the properties of microalgae. •A new protocol termed as “chemical modulator based adaptive laboratory evolution” (CM-ALE) was developed for C. cohnii.•Carbon equivalents were redirected from starch to lipid in the evolved strain after sethoxydim based CM-ALE.•Sensitivity of sesamol to C. cohnii was relived after sesamol based CM-ALE.•After two-step CM-ALE, the lipid and DHA productivity in C. cohnii was respectively doubled with addition of 1 mM sesamol.