Center for Marine Environmental Ecology, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China.
Polar Research Institute of China, Shanghai 200136, China.
Mar Drugs. 2021 Oct 7;19(10):564. doi: 10.3390/md19100564.
species are one of the best oleaginous thraustochytrids for high-yield production of docosahexaenoic acid (DHA, 22:6). However, the DHA yields from most wild-type (WT) strains of are unsatisfactory for large-scale production. In this study, we applied the atmospheric and room-temperature plasma (ARTP) tool to obtain the mutant library of a previously isolated strain of (i.e., PKU#Mn4). Two rounds of ARTP mutagenesis coupled with the acetyl-CoA carboxylase (ACCase) inhibitor (clethodim)-based screening yielded the mutant A78 that not only displayed better growth, glucose uptake and ACCase activity, but also increased (54.1%) DHA content than that of the WT strain. Subsequent optimization of medium components and supplementation improved the DHA content by 75.5 and 37.2%, respectively, compared with that of mutant A78 cultivated in the unoptimized medium. Interestingly, the ACCase activity of mutant A78 in a medium supplemented with biotin, citric acid or sodium citrate was significantly greater than that in a medium without supplementation. This study provides an effective bioengineering approach for improving the DHA accumulation in oleaginous microbes.
是产油能力最强的二十二碳六烯酸（DHA，22:6）生产菌之一。然而，大多数野生型（WT）菌株的 DHA 产量都不能满足大规模生产的要求。在本研究中，我们采用大气压室温等离子体（ARTP）诱变技术，构建了先前分离得到的一株 的突变体文库（即 PKU#Mn4）。两轮 ARTP 诱变结合乙酰辅酶 A 羧化酶（ACCase）抑制剂（噻虫啉）筛选，得到了突变株 A78，该突变株不仅表现出更好的生长、葡萄糖摄取和 ACCase 活性，而且 DHA 含量比 WT 菌株提高了 54.1%。随后对培养基成分进行优化和补充，与在未优化的培养基中培养的突变株 A78 相比，分别提高了 75.5%和 37.2%的 DHA 含量。有趣的是，在添加生物素、柠檬酸或柠檬酸钠的培养基中，突变株 A78 的 ACCase 活性显著高于不添加的培养基。本研究为提高油脂微生物中 DHA 的积累提供了一种有效的生物工程方法。
