Microbial Synthesis of Pinene
Microbial Synthesis of Pinene
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DOI：
10.1021/sb4001382
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发表时间：
2014-07-01
影响因子：
4.7
通讯作者：
Peralta-Yahya, Pamela
中科院分区：
文献类型：
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作者：
Sarria, Stephen;Wong, Betty;Peralta-Yahya, Pamela
今天的生物燃料的体积热值太低，无法为能源密集型飞机、火箭和导弹提供动力。最近，研究表明，蒎烯二聚体的体积热值与战术燃料JP-10相似。为了提供一个可持续的来源，我们工程大肠杆菌的蒎烯生产。我们组合表达了三种蒎烯脱氢酶（PS）和三种香叶基二磷酸脱氢酶（GPPS），最佳组合达到与28 mg/L的蒎烯相似。我们推测，蒎烯毒性限制生产，但是，毒性不应该限制在目前的滴度。由于GAPS被香叶基二磷酸（GPP）抑制，并且为了增加通过该途径的通量，我们组合构建了GPPS-PS蛋白融合体。GPPS-PS融合体产生32 mg/L的蒎烯，比先前报道的工程E.杆菌最后，我们研究了我们的产蒎烯微生物的蒎烯异构体比率，发现异构体分布不仅由所使用的PS的身份决定，而且还由与PS配对的GPPS的身份决定。我们证明，GPP的浓度可用于PS环化改变了蒎烯异构体的比例。
The volumetric heating values of today's biofuels are too low to power energy-intensive aircraft, rockets, and missiles. Recently, pinene dimers were shown to have a volumetric heating value similar to that of the tactical fuel JP-10. To provide a sustainable source of pinene, we engineered Escherichia coli for pinene production. We combinatorially expressed three pinene synthases (PS) and three geranyl diphosphate synthases (GPPS), with the best combination achieving similar to 28 mg/L of pinene. We speculated that pinene toxicity was limiting production; however, toxicity should not be limiting at current titers. Because GAPS is inhibited by geranyl diphosphate (GPP) and to increase flux through the pathway, we combinatorially constructed GPPS-PS protein fusions. The Abies grandis GPPS-PS fusion produced 32 mg/L of pinene, a 6-fold improvement over the highest titer previously reported in engineered E. coli. Finally, we investigated the pinene isomer ratio of our pinene-producing microbe and discovered that the isomer profile is determined not only by the identity of the PS used but also by the identity of the GPPS with which the PS is paired. We demonstrated that the GPP concentration available to PS for cyclization alters the pinene isomer ratio.