Department of Life Science, Hanyang University, Seoul, South Korea.
School of Biological Sciences, Seoul National University, Seoul, South Korea.
Biotechnol Bioeng. 2018 Mar;115(3):719-728. doi: 10.1002/bit.26499. Epub 2017 Dec 1.
Lutein and zeaxanthin are dietary carotenoids reported to be protective against age-related macular degeneration. Recently, the green alga Chlamydomonas reinhardtii has received attention as a photosynthetic cell factory, but the potential of this alga for carotenoid production has not yet been evaluated. In this study, we selected the C. reinhardtii CC-4349 strain as the best candidate among seven laboratory strains tested for carotenoid production. A knock-out mutant of the zeaxanthin epoxidase gene induced by preassembled DNA-free CRISPR-Cas9 ribonucleoproteins in the CC-4349 strain had a significantly higher zeaxanthin content (56-fold) and productivity (47-fold) than the wild type without the reduction in lutein level. Furthermore, we produced eggs fortified with lutein (2-fold) and zeaxanthin (2.2-fold) by feeding hens a diet containing the mutant. Our results clearly demonstrate the possibility of cost-effective commercial use of microalgal mutants induced by DNA-free CRISPR-Cas9 ribonucleoproteins in algal biotechnology for the production of high-value products.
叶黄素和玉米黄质是膳食类胡萝卜素，据报道它们具有预防年龄相关性黄斑变性的作用。最近，绿藻莱茵衣藻作为光合细胞工厂受到关注，但这种藻类用于类胡萝卜素生产的潜力尚未得到评估。在这项研究中，我们选择 C. reinhardtii CC-4349 菌株作为在七种实验室菌株中进行类胡萝卜素生产测试的最佳候选菌株。使用预先组装的无 DNA 的 CRISPR-Cas9 核糖核蛋白在 CC-4349 菌株中诱导的玉米黄质环氧化酶基因敲除突变体的玉米黄质含量（56 倍）和生产力（47 倍）显著高于野生型，而叶黄素水平没有降低。此外，我们通过给母鸡喂食含有突变体的饮食来生产强化了叶黄素（2 倍）和玉米黄质（2.2 倍）的鸡蛋。我们的研究结果清楚地表明，在藻类生物技术中，使用无 DNA 的 CRISPR-Cas9 核糖核蛋白诱导的微藻突变体来生产高价值产品具有经济有效的商业应用可能性。
