Li Chunji, Li Bingxue, Zhang Ning, Wang Qifan, Wang Wenjing, Zou Hongtao
College of Land and Environment, Shenyang Agricultural University.
College of Bioscience and Biotechnology, Shenyang Agricultural University.
J Gen Appl Microbiol. 2019 Jul 19;65(3):121-128. doi: 10.2323/jgam.2018.07.002. Epub 2018 Dec 13.
Carotenoids are ubiquitous constituents of living organisms. These structurally diverse pigments have received considerable attention due to their biotechnological applications and potential beneficial effects on human health. In this study, we characterized an over-producing β-carotene mutant of Sporidiobolus pararoseus, obtained by ultraviolet mutagenesis, named MuY9. We compared the transcriptome between the wild-type and MuY9. A total of 348 differential expressed genes (DEGs) were found, and only one DEG crtYB is involved in carotenoid biosynthesis. The overproduction of β-carotene in MuY9 should be attributed to the up-regulation of crtYB. Functional identification of crtYB was performed using heterologous complementation in Escherichia coli. Our findings indicate that the enzymatic conversions of geranylgeranyl pyrophosphate to phytoene, as well as lycopene to β-carotene, are catalyzed by this CrtYB. Furthermore, our insights into the crtYB gene should facilitate a more detailed understanding of the carotenogenic pathway in S. pararoseus, and advance the development of the genetic engineering for the bio-production of carotenoids.
类胡萝卜素是生物体中普遍存在的成分。这些结构多样的色素因其生物技术应用以及对人类健康的潜在有益影响而受到了广泛关注。在本研究中，我们对一株通过紫外线诱变获得的产β-胡萝卜素过量的嗜玫色掷孢酵母突变体MuY9进行了表征。我们比较了野生型和MuY9之间的转录组。共发现348个差异表达基因（DEG），且只有一个DEG即crtYB参与类胡萝卜素生物合成。MuY9中β-胡萝卜素的过量产生应归因于crtYB的上调。利用大肠杆菌中的异源互补对crtYB进行了功能鉴定。我们的研究结果表明，该CrtYB催化了牻牛儿基牻牛儿基焦磷酸向八氢番茄红素的酶促转化以及番茄红素向β-胡萝卜素的酶促转化。此外，我们对crtYB基因的深入了解应有助于更详细地理解嗜玫色掷孢酵母中的类胡萝卜素生成途径，并推动类胡萝卜素生物生产的基因工程发展。
