Sun Xiao-Man, Ren Lu-Jing, Zhao Quan-Yu, Ji Xiao-Jun, Huang He
1College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816 People's Republic of China.
4Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing, People's Republic of China.
Biotechnol Biofuels. 2018 Oct 4;11:272. doi: 10.1186/s13068-018-1275-9. eCollection 2018.
Microalgae have drawn great attention as promising sustainable source of lipids and carotenoids. Their lipid and carotenoids accumulation machinery can be trigged by the stress conditions such as nutrient limitation or exposure to the damaging physical factors. However, stressful conditions often adversely affect microalgal growth and cause oxidative damage to the cells, which can eventually reduce the yield of the desired products. To overcome these limitations, two-stage cultivation strategies and supplementation of growth-promoting agents have traditionally been utilized, but developing new highly adapted strains is theoretically the simplest strategy. In addition to genetic engineering, adaptive laboratory evolution (ALE) is frequently used to develop beneficial phenotypes in industrial microorganisms during long-term selection under specific stress conditions. In recent years, many studies have gradually introduced ALE as a powerful tool to improve the biological properties of microalgae, especially for improving the production of lipid and carotenoids. In this review, strategies for the manipulation of stress in microalgal lipids and carotenoids production are summarized and discussed. Furthermore, this review summarizes the overall state of ALE technology, including available selection pressures, methods, and their applications in microalgae for the improved production of lipids and carotenoids.
微藻作为有前景的可持续脂质和类胡萝卜素来源已引起极大关注。它们的脂质和类胡萝卜素积累机制可被营养限制或暴露于有害物理因素等应激条件触发。然而，应激条件常常对微藻生长产生不利影响，并对细胞造成氧化损伤，这最终会降低所需产物的产量。为克服这些限制，传统上采用了两阶段培养策略和添加生长促进剂的方法，但从理论上讲，培育新的高度适应性菌株是最简单的策略。除了基因工程外，适应性实验室进化（ALE）在特定应激条件下的长期选择过程中，常用于培育工业微生物的有益表型。近年来，许多研究已逐渐引入ALE作为改善微藻生物学特性的有力工具，尤其是用于提高脂质和类胡萝卜素的产量。在本综述中，总结并讨论了微藻脂质和类胡萝卜素生产中应激调控的策略。此外，本综述总结了ALE技术的整体状况，包括可用的选择压力、方法及其在微藻中用于提高脂质和类胡萝卜素产量的应用。
