Srivastava Vaibhav, Sarnaik Aditya P, Wangikar Pramod P
Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India.
Biotechnol Prog. 2025 Jan-Feb;41(1):e3509. doi: 10.1002/btpr.3509. Epub 2024 Sep 15.
Alkanes are high-energy hydrocarbons that are foreseen as next generation biofuels. Cyanobacteria are known to naturally synthesize C15-C19 alkanes; however, the titers are too low to make this a commercially viable process. Therefore, to leverage these photosynthetic platforms for improved alkane production, here we engineered three novel isolates of Synechococcus elongatus PCC 11801, PCC 11802, and IITB6. The two gene AAR-ADO alkane biosynthesis pathway was constructed by cloning the genes for acyl-ACP reductase (aar) and aldehyde deformylating oxygenase (ado) from S. elongatus PCC 7942 under the regulation of P promoter from PCC 7942 and native promoters from PCC 11801 such as P, P, and P. The genes were separately cloned under two different promoters, creating a library of the engineered strains. The results indicated that the engineered strains of novel S. elongatus isolates produced significantly higher amounts of alkanes than the model strain PCC 7942. The highest alkane yield achieved was 4.1 mg/gDCW in BG-11, while the highest titer was 31.5 mg/L in 5X BG-11, with an engineered IITB6 strain (P:aar:T::P:ado:T). Overall, the study highlights the potential of newly isolated S. elongatus strains as efficient alkane production platforms.
烷烃是高能碳氢化合物，被视为下一代生物燃料。已知蓝藻能自然合成C15 - C19烷烃；然而，其产量过低，无法使其成为具有商业可行性的工艺。因此，为利用这些光合平台提高烷烃产量，我们在此构建了三种新型的聚球藻属菌株，即细长聚球藻PCC 11801、PCC 11802和IITB6。通过在来自PCC 7942的P启动子以及来自PCC 11801的天然启动子（如P、P和P）的调控下，克隆来自细长聚球藻PCC 7942的酰基 - ACP还原酶（aar）和醛脱甲酰基加氧酶（ado）基因，构建了双基因AAR - ADO烷烃生物合成途径。这些基因分别在两种不同的启动子下进行克隆，创建了工程菌株文库。结果表明，新型细长聚球藻分离株的工程菌株产生的烷烃量显著高于模式菌株PCC 7942。在BG - 11中实现的最高烷烃产量为4.1毫克/克干重，而在5X BG - 11中最高滴度为31.5毫克/升，使用的是工程IITB6菌株（P:aar:T::P:ado:T）。总体而言，该研究突出了新分离的细长聚球藻菌株作为高效烷烃生产平台的潜力。
