β-胡蘿卜素是一種天然色素,，屬于四萜類(lèi)化合物,，有很高的藥理學(xué)及營(yíng)養(yǎng)學(xué)價(jià)值,，現(xiàn)在已廣泛應(yīng)用于醫(yī)藥、保健品,、食品添加劑及化妝品等行業(yè)。構(gòu)建高效合成β-胡蘿卜素的微生物菌株具有良好的應(yīng)用前景,。
中國(guó)科學(xué)院武漢植物園天然產(chǎn)物合成生物學(xué)學(xué)科組碩士研究生李倩在章焰生研究員的指導(dǎo)下,，于釀酒酵母中重構(gòu)了β-胡蘿卜素的生物合成途徑，將來(lái)源于紅發(fā)夫酵母中與β-胡蘿卜素合成相關(guān)的基因crtYB（八氫番茄紅素合成酶及番茄紅素環(huán)化酶基因）和crtI（八氫番茄紅素脫氫酶基因）轉(zhuǎn)入釀酒酵母,，并對(duì)這兩個(gè)基因進(jìn)行了密碼子的優(yōu)化,；同時(shí)通過(guò)過(guò)量表達(dá)異戊稀代謝途徑中的關(guān)鍵限速酶HMGR（3-羥基-3-甲基戊二酰輔酶A還原酶）基因,，發(fā)現(xiàn)菌株β-胡蘿卜素的產(chǎn)量提高了很多,，且對(duì)釀酒酵母的生長(zhǎng)無(wú)影響,，最終得到具備高效合成β-胡蘿卜素能力的釀酒酵母工程菌株,。
該研究為釀酒酵母大規(guī)模生產(chǎn)β-胡蘿卜素提供依據(jù),，也為釀酒酵母中萜類(lèi)物質(zhì)生物合成及代謝工程改造提供了一定的理論基礎(chǔ),。相關(guān)研究結(jié)果發(fā)表在國(guó)際學(xué)術(shù)期刊FEMS Microbiology Letters（2013， 345(2),， 94-101）上（生物谷Bioon.com）。
生物谷推薦的英文摘要
FEMS Microbiology Letters DOI: 10.1111/1574-6968.12187
Enhancing beta-carotene production in Saccharomyces cerevisiae by metabolic engineering
Qian Li1,，2,， Zhiqiang Sun1,，2， Jing Li1，2,， Yansheng Zhang1，*
Beta-carotene is known to exhibit a number of pharmacological and nutraceutical benefits to human health. Metabolic engineering of beta-carotene biosynthesis in Saccharomyces cerevisiae has been attracting the interest of many researchers. A previous work has shown that S. cerevisiae successfully integrated with phytoene synthase (crtYB) and phytoene desaturase (crtI) from Xanthophyllomyces dendrorhous could produce beta-carotene. In the present study,， we achieved around 200% improvement in beta-carotene production in S. cerevisiae through specific site optimization of crtI and crtYB， in which five codons of crtI and eight codons of crtYB were rationally mutated. Furthermore,， the effects of the truncated HMG-CoA reductase (tHMG1) from S. cerevisiae and HMG-CoA reductase (mva) from Staphylococcus aureus on the production of beta-carotene in S. cerevisiae were also evaluated. Our results indicated that mva from a prokaryotic organism might be more effective than tHMG1 for beta-carotene production in S. cerevisiae.
