Overproduction of docosahexaenoic acid in Schizochytrium sp. through genetic engineering of oxidative stress defense pathways

Biotechnology for Biofuels

Ying Wen¹  Xiao Han¹  Zhi Chen¹  Zhaohui Li¹ 

[1] State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, 100193, Beijing, China;

关键词: Schizochytrium;    Docosahexaenoic acid;    Genetic engineering;    Oxidative stress defense pathway;   

DOI  :  10.1186/s13068-021-01918-w

来源: Springer

【 摘 要 】

BackgroundOxidation and peroxidation of lipids in microorganisms result in increased levels of intracellular reactive oxygen species (ROS) and reactive aldehydes, and consequent reduction of cell growth and lipid accumulation.ResultsTo reduce oxygen-mediated cell damage and increase lipid and docosahexaenoic acid (DHA) production in Schizochytrium sp., we strengthened the oxidative stress defense pathways. Overexpression of the enzymes thioredoxin reductase (TRXR), aldehyde dehydrogenase (ALDH), glutathione peroxidase (GPO), and glucose-6-phosphate dehydrogenase (ZWF) strongly promoted cell growth, lipid yield, and DHA production. Coexpression of ZWF, ALDH, GPO, and TRXR enhanced ROS-scavenging ability. Highest values of dry cell weight, lipid yield, and DHA production (50.5 g/L, 33.1 g/L, and 13.3 g/L, respectively) were attained in engineered strain OaldH-gpo-trxR by shake flask fed-batch culture; these were increases of 18.5%, 80.9%, and 114.5% relative to WT values.ConclusionsOur findings demonstrate that engineering of oxidative stress defense pathways is an effective strategy for promoting cell robustness, lipid yield, and DHA production in Schizochytrium.

【 授权许可】

CC BY