Abstract：
Cyanobacteria are the prospective biosolar cell factories to produce a range of bioproducts through CO2 sequestration. Farnesene is a sesquiterpene with an array of applications in biofuels, pest management, cosmetics, flavours and fragrances. This is the first time a codon-optimized farnesene synthase (AFS) gene is engineered into the genomic neutral site of Synechococcus elongatus UTEX 2973 for farnesene synthesis through its endogenous methylerythritol phosphate (MEP) pathway, rendering UTEX AFS strain. Similarly, bottleneck gene(s) of the MEP pathway, 1-deoxy-D-xylulose-5-phosphate synthase (dxs) and/or fusion of isopentenyl diphosphate isomerase and farnesyl diphosphate synthase (idispA) were engineered engendering UTEX AFS::dxs, UTEX AFS::idispA and UTEX AFS::dxs::idispA strains. UTEX AFS::dxs::idispA achieves farnesene productivity of 2.57 mg/L/day, the highest among engineered cyanobacterial strains studied so far. It demonstrates farnesene production, which is 31.3-times higher than the UTEX AFS strain. Moreover, the engineered strains show similar productivity over a three-month period, stipulating the genetic stability of the strains.
摘要：
蓝细菌是通过二氧化碳封存生产一系列生物产品的潜在生物太阳能电池工厂。金合欢烯是一种倍半萜，在生物燃料中具有多种应用，害虫管理，化妆品,香料和香料。这是首次将密码子优化的法呢烯合酶（AFS）基因改造到延伸神经神经球菌UTEX2973的基因组中性位点，通过其内源性甲基赤藓糖醇磷酸（MEP）途径合成法呢烯，呈现UTEXAFS菌株。同样，MEP途径的瓶颈基因，1-脱氧-D-木酮糖-5-磷酸合酶（dxs）和/或异戊烯基二磷酸异构酶和法尼基二磷酸合酶（ipisA）的融合体被设计为UTEXAFS::dxs，UTEXAFS::idispA和UTEXAFS::dxs::idispA菌株。UTEXAFS::dxs::idispA实现了2.57mg/L/天的法尼烯生产率，迄今为止研究的工程蓝藻菌株中最高。它展示了法尼烯的生产，比UTEXAFS菌株高31.3倍。此外，工程菌株在三个月内表现出相似的生产力，规定菌株的遗传稳定性。
