Photosynthetic conversion of CO2 and low grade heat from biorefineries into linalool

主要研究者：周阮宝提案编号：1133951在发酵过程中，生物精炼厂通常以二氧化碳（CO2）的形式释放约三分之一的碳水化合物碳。理想情况下，光合微生物可以被改造成将二氧化碳直接转化为液体运输燃料。不幸的是，目前使用光合微生物从CO2中制造燃料的方法面临许多技术挑战，包括需要收获细胞，提取能量密集的油，然后将油转化为最终产品。 为了应对这些挑战，拟议的研究将对两种蓝藻（鱼腥藻PCC 7120和Nostoc punctiforme）进行基因工程改造，以直接生产和分泌芳樟醇，一种十碳萜烯醇，通过非melavonate（MEP）途径，使用阳光作为能源和CO2作为碳原料。 为了加强芳樟醇的生产，还将努力对蓝细菌进行基因工程改造，以提高光合作用CO2固定的速率，并通过关闭竞争固定碳的不必要途径，将碳流重新导向芳樟醇合成。 为此，提出了三个研究计划：1）将最佳林斯基因稳定插入蓝藻染色体; 2）校正代谢流以最大化芳樟醇产量; 3）评估光合和异养条件下芳樟醇的产量。 将在使用相分离回收芳樟醇的再循环光生物反应器系统中评估工程菌株的性能。芳樟醇产量和生产力将投入的要求进行比较。更广泛的影响拟议的教育和推广活动将侧重于通过2+2+2计划在南达科他州州立大学（SDSU）为美国土著学生提供机会。 首先，为期一周的代谢工程活动将作为夏季研究所计划的一部分。通过这些活动，美国原住民高中学生和他们的老师将被招募参加为期6-8周的暑期研究实习。教师将利用研究经验开发课堂/实验室活动，与学生分享。 学生将参加正在进行的项目，然后将有机会在通过科学和SDSU的南达科他州科学院组织的科学会议上介绍他们的努力？本科生研究日。 谁参加部落学院，然后转移到SDSU的美洲原住民本科生也将提供夏季研究经验。

PI: Ruanbao ZhouProposal Number: 1133951Intellectual MeritBiorefineries typically release about one third of the carbohydrate carbon as carbon dioxide (CO2) during fermentation. Ideally, a photosynthetic microorganism could be engineered to convert CO2 directly into liquid transportation fuels. Unfortunately, current approaches for using photosynthetic microorganisms to make fuel from CO2 suffer from many technical challenges, including the need to harvest cells, extract the energy-dense oils, and then convert the oil into the final product. To address these challenges, the proposed research will genetically engineer two cyanobacteria (Anabaena sp. PCC7120 and Nostoc punctiforme) to directly produce and secrete linalool, a ten-carbon terpene alcohol, through the non melavonate (MEP) pathway using sunlight as the energy source and CO2 as the carbon feedstock. To intensify linalool production, efforts will also be made to genetically engineer the cyanobacteria to increase the rate of photosynthetic CO2 fixation, and to re-direct the carbon flow to linalool synthesis by shutting unnecessary pathways that compete for fixed carbon. Towards this end, the proposed research plan has three components: 1) stable insertion of optimal LinS gene into chromosome of cyanobacteria; 2) correct metabolic flux to maximize linalool productivity; 3) assess linalool production under both photosynthetic andheterotrophic conditions. The performance of the engineered strains will be assessed in a recirculating photobioreactor system that uses phase separation for linalool recovery. Linalool yield and productivity will be compared to input requirements.Broader ImpactsThe proposed education and outreach activities will focus on providing opportunities for Native American students through the 2+2+2 Program at the South Dakota State University (SDSU). First, week-long activities in metabolic engineering will be developed as part of the summer institute program. Through these activities, Native American high school students and their teachers will be recruited to participate in 6-8 week long, summer research internships. Teachers will use the research experience to develop classroom/lab activities to share with their students. Students will participate in on-going projects, and then will be given the opportunity to present their efforts at scientific meetings organized through the South Dakota Academy of Science and SDSU?s Undergraduate Research Day. Native American undergraduate students who attend tribal colleges and then transfer to SDSU will also be offered summer research experiences.