Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P. R. China.
Xi'an Healthful Biotechnology Co., Ltd. , HangTuo Road , Chang'an, Xi'an 710100 , P. R. China.
J Agric Food Chem. 2019 Aug 28;67(34):9560-9568. doi: 10.1021/acs.jafc.9b02597. Epub 2019 Aug 15.
β-Carotene is a precursor of vitamin A and a dietary supplement for its antioxidant property. Producing β-carotene by microbial fermentation has attracted much attention owing to consumers' preference for the natural product. In this study, an engineered photosynthetic producing β-carotene was constructed by the following strategies: (1) five promoters of different strengths were used to investigate the effect of the expression level of on β-carotene content. It was found that P increased the β-carotene content by 109%. (2) blocking of the branched pentose phosphate pathway by deletion, and (3) overexpressing could restore the transcriptional levels of and . Finally, the engineered RS-C3 has the highest β-carotene content of 14.93 mg/g dry cell weight (DCW) among all of the reported photosynthetic bacteria and the β-carotene content reached 3.34 mg/g DCW under light conditions. Our results will be available for industrial use to supply a large quantity of natural β-carotene.
β-胡萝卜素是维生素 A 的前体，具有抗氧化特性，因此被用作膳食补充剂。由于消费者更喜欢天然产品，因此通过微生物发酵生产β-胡萝卜素引起了广泛关注。在这项研究中，通过以下策略构建了一种工程化的光合微生物来生产β-胡萝卜素：（1）使用了五个不同强度的启动子来研究 表达水平对β-胡萝卜素含量的影响。结果发现，P 使β-胡萝卜素含量增加了 109%。（2）通过 删除阻断分支戊糖磷酸途径，以及（3）过表达 可以恢复 和 的转录水平。最后，工程化的 RS-C3 的β-胡萝卜素含量最高，达到每克干重（DCW）14.93 毫克，在所有已报道的光合细菌中最高，在光照条件下β-胡萝卜素含量达到每克 DCW3.34 毫克。我们的研究结果将可用于工业生产，以提供大量的天然β-胡萝卜素。
