SINOPEC CORP. Research Institute of Petroleum Processing (RIPP) , Beijing 100083 , P. R. China.
Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300072 , P. R. China.
J Agric Food Chem. 2019 Sep 4;67(35):9858-9867. doi: 10.1021/acs.jafc.9b03907. Epub 2019 Aug 19.
Farnesene is an important chemical platform for many industrial products, such as biofuels and polymers. We performed high-efficiency utilization of corncobs for β-farnesene production by separate hydrolysis and fermentation with an optimized strain. First, we developed a recycling strategy for both corncob pretreatment and cellulose hydrolysis, which saved great amounts of pretreatment reagents and presented a 96.83% cellulose conversion rate into glucose. However, the corncob hydrolysate strongly repressed cell growth and β-farnesene production, being caused by high-concentrated citrate. Through expressing a heterologous ATP citrate lyase and screening for a suitable expression host, an optimized strain was constructed that produced β-farnesene at 4.06 g/L after 48 h in a 5 L fermenter, representing an approximately 2.3-fold increase over the initial strain. Therefore, the proposed strategy about the recycling process and repression elimination was successful and suitable for the production of lignocellulosic-based β-farnesene, which can be further studied to scale up for industrialization.
法呢烯是许多工业产品（如生物燃料和聚合物）的重要化学平台。我们通过优化的菌株，对玉米芯进行单独的水解和发酵，实现了 β-法呢烯的高效利用。首先，我们开发了一种玉米芯预处理和纤维素水解的循环策略，该策略节省了大量预处理试剂，并将纤维素转化率提高到了 96.83%，转化为葡萄糖。然而，玉米芯水解物强烈抑制细胞生长和 β-法呢烯的生产，这是由于高浓度的柠檬酸引起的。通过表达一种异源三磷酸腺苷柠檬酸裂解酶，并筛选合适的表达宿主，构建了一个优化的菌株，该菌株在 5 L 发酵罐中 48 小时后生产 4.06 g/L 的 β-法呢烯，比初始菌株提高了约 2.3 倍。因此，所提出的关于循环过程和抑制消除的策略是成功的，适用于木质纤维素基 β-法呢烯的生产，可以进一步研究以扩大工业化规模。
