Couto Márcia R, Rodrigues Joana L, Rodrigues Lígia R
Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
J R Soc Interface. 2017 Aug;14(133). doi: 10.1098/rsif.2017.0470.
Curcumin is a plant secondary metabolite with outstanding therapeutic effects. Therefore, there is a great interest in developing new strategies to produce this high-value compound in a cheaper and environmentally friendly way. Curcumin heterologous production in using artificial biosynthetic pathways was previously demonstrated using synthetic biology approaches. However, the culturing conditions to produce this compound were not optimized and so far only a two-step fermentation process involving the exchange of culture medium allowed high concentrations of curcumin to be obtained, which limits its production at an industrial scale. In this study, the culturing conditions to produce curcumin were evaluated and optimized. In addition, it was concluded that BL21 allows higher concentrations of curcumin to be produced than K-12 strains. Different isopropyl β-d-thiogalactopyranoside concentrations, time of protein expression induction and substrate type and concentration were also evaluated. The highest curcumin production obtained was 959.3 µM (95.93% of per cent yield), which was 3.1-fold higher than the highest concentration previously reported. This concentration was obtained using a two-stage fermentation with lysogeny broth (LB) and M9. Moreover, terrific broth was also demonstrated to be a very interesting alternative medium to produce curcumin because it also led to high concentrations (817.7 µM). The use of this single fermentation medium represents an advantage at industrial scale and, although the final production is lower than that obtained with the LB-M9 combination, it leads to a significantly higher production of curcumin in the first 24 h of fermentation. This study allowed obtaining the highest concentrations of curcumin reported so far in a heterologous organism and is of interest for all of those working with the heterologous production of curcuminoids, other complex polyphenolic compounds or plant secondary metabolites.
姜黄素是一种具有显著治疗效果的植物次生代谢产物。因此，人们对开发以更廉价且环保的方式生产这种高价值化合物的新策略有着浓厚兴趣。此前已通过合成生物学方法证明了利用人工生物合成途径在[具体宿主]中进行姜黄素的异源生产。然而，生产该化合物的培养条件尚未优化，到目前为止，只有涉及更换培养基的两步发酵过程才能获得高浓度的姜黄素，这限制了其在工业规模上的生产。在本研究中，对生产姜黄素的培养条件进行了评估和优化。此外，得出的结论是，与K - 12菌株相比，BL21能够产生更高浓度的姜黄素。还评估了不同浓度的异丙基β - D -硫代半乳糖苷、蛋白质表达诱导时间以及底物类型和浓度。获得的最高姜黄素产量为959.3 μM（产率为95.93%），这比先前报道的最高浓度高出3.1倍。该浓度是通过使用溶菌肉汤（LB）和M9进行两阶段发酵获得的。此外， terrific肉汤也被证明是生产姜黄素的一种非常有吸引力的替代培养基，因为它也能产生高浓度（817.7 μM）。使用这种单一发酵培养基在工业规模上具有优势，尽管最终产量低于LB - M9组合，但在发酵的前24小时内姜黄素的产量显著更高。本研究使得在异源生物体中获得了迄今为止报道的最高浓度的姜黄素，对于所有从事姜黄素类、其他复杂多酚化合物或植物次生代谢产物异源生产的人来说都具有重要意义。
