Lipid engineering combined with systematic metabolic engineering of Saccharomyces cerevisiae for high-yield production of lycopene
Lipid engineering combined with systematic metabolic engineering of Saccharomyces cerevisiae for high-yield production of lycopene
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DOI：
10.1016/j.ymben.2018.11.009
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发表时间：
2019-03-01
影响因子：
8.4
通讯作者：
Liu, Tiangang
中科院分区：
文献类型：
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作者：
Ma, Tian;Shi, Bin;Liu, Tiangang
酿酒酵母是天然化合物生产的高效宿主，在学术研究和生物工业中得到了广泛的应用。然而，酿酒酵母对亲脂性天然产物的生产能力有限，特别是在细胞内积累的化合物，如多酮和类胡萝卜素，一些工程化合物显示出细胞毒性。在这项研究中，我们使用一种受自然启发的策略来建立一个有效的平台来改善脂肪油-三酰甘油(TAG)的代谢，并使番茄红素积累增加。通过系统的传统工程方法，实现了番茄红素56.2 mg/g细胞干重(CDW)的较高水平生产。为了关注Tag代谢以增加番茄红素的积累，我们过表达了与脂肪酸合成和Tag产生相关的关键基因，随后通过过表达脂肪酸去饱和酶(OLE1)和调节脂滴大小的Seipin(FLD1)来调节Tag的脂肪酰基组成。结果表明，该工程菌番茄红素产量为70.5 mg/gCDW，比原高产菌株提高25%，补料分批发酵番茄红素产量分别达到2.37g/L和73.3 mg/gCDW，是迄今为止报道的酿酒酵母番茄红素产量最高的菌株。这些发现为通过脂质工程进行更广泛的系统代谢工程提供了一种有效的策略。
Saccharomyces cerevisiae is an efficient host for natural-compound production and preferentially employed in academic studies and bioindustries. However, S. cerevisiae exhibits limited production capacity for lipophilic natural products, especially compounds that accumulate intracellularly, such as polyketides and carotenoids, with some engineered compounds displaying cytotoxicity. In this study, we used a nature-inspired strategy to establish an effective platform to improve lipid oil-triacylglycerol (TAG) metabolism and enable increased lycopene accumulation. Through systematic traditional engineering methods, we achieved relatively high-level production at 56.2 mg lycopene/g cell dry weight (cdw). To focus on TAG metabolism in order to increase lycopene accumulation, we overexpressed key genes associated with fatty acid synthesis and TAG production, followed by modulation of TAG fatty acyl composition by overexpressing a fatty acid desaturase (OLE1) and deletion of Seipin (FLD1), which regulates lipid-droplet size. Results showed that the engineered strain produced 70.5 mg lycopene/g cdw, a 25% increase relative to the original high-yield strain, with lycopene production reaching 2.37 g/L and 73.3 mg/g cdw in fed-batch fermentation and representing the highest lycopene yield in S. cerevisiae reported to date. These findings offer an effective strategy for extended systematic metabolic engineering through lipid engineering.