Improved production of echinenone and canthaxanthin in transgenic Nostoc sp. PCC 7120 overexpressing a heterologous crtO gene from Nostoc flagelliforme
Improved production of echinenone and canthaxanthin in transgenic Nostoc sp. PCC 7120 overexpressing a heterologous crtO gene from Nostoc flagelliforme
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转基因发菜中海胆酮和角黄素的产量得到提高。
DOI：
10.1016/j.micres.2020.126455
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发表时间：
2020-06-01
影响因子：
6.7
通讯作者：
Ye, Shuifeng
中科院分区：
文献类型：
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作者：
Gao, Xiang;Xu, Haiyan;Ye, Shuifeng
紫锥花酮和角黄素是重要的类胡萝卜素色素，在食品和工业上有广泛的应用。以β-胡萝卜素为底物，用β-胡萝卜素酮酶(CrtO)催化紫锥酮和/或角黄素的生物合成。在本研究中，我们获得了转基因发菜。PCC7120高效表达发菜的异源crtO基因，并对两种色素的产量进行了评价。在正常(BG11培养基，30℃)和渗透胁迫(BG11培养基中添加0.4M甘露醇，30℃)条件下进行培养。与对照菌株相比，在正常和渗透胁迫条件下，转基因菌株的紫锥菊酮和角黄素的产量分别提高了16%和80%以上。特别是在胁迫条件下，紫锥菊酮和角黄素在总色素中所占比例较高，有利于后续分离提纯。此外，转基因菌株具有较强的耐旱性，在复湿后可从干燥处理中恢复。本研究为在工程蓝藻中生产这两种色素以及蓝藻厌水生物工程提供了技术线索。
Echinenone and canthaxanthin are important carotenoid pigments with food and industrial applications. Biosynthesis of echinenone and/or canthaxanthin is catalyzed by beta-carotene ketolase (CrtO), with beta-carotene as the substrate. In this study, we generated transgenic Nostoc sp. PCC 7120 overexpressing a heterologous crtO gene from Nostoc flagelliforme and evaluated the productivity of both pigments. Normal (BG11 medium, 30 degrees C) and osmotic stress (BG11 medium supplemented with 0.4 M mannitol, 30 degrees C) conditions were used for cultivation. As compared to control strain, production of echinenone and canthaxanthin in transgenic strain were respectively increased by more than 16 % and 80 %, under either normal or osmotic stress conditions. Especially upon the stress condition, higher proportion of echinenone and canthaxanthin in total pigments was achieved, which should be beneficial for downstream separation and purification. In addition, transgenic strain showed drought tolerance and could revive from desiccation treatment after rewetting. Thus, this study provided technical clues for production of both pigments in engineered cyanobacteria as well as for cyanobacterial anhydrobiotic engineering.