Buijs Nicolaas A, Zhou Yongjin J, Siewers Verena, Nielsen Jens
Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
Biotechnol Bioeng. 2015 Jun;112(6):1275-9. doi: 10.1002/bit.25522. Epub 2015 Jan 16.
In the past decade industrial-scale production of renewable transportation biofuels has been developed as an alternative to fossil fuels, with ethanol as the most prominent biofuel and yeast as the production organism of choice. However, ethanol is a less efficient substitute fuel for heavy-duty and maritime transportation as well as aviation due to its low energy density. Therefore, new types of biofuels, such as alkanes, are being developed that can be used as drop-in fuels and can substitute gasoline, diesel, and kerosene. Here, we describe for the first time the heterologous biosynthesis of long-chain alkanes by the yeast Saccharomyces cerevisiae. We show that elimination of the hexadecenal dehydrogenase Hfd1 and expression of a redox system are essential for alkane biosynthesis in yeast. Deletion of HFD1 together with expression of an alkane biosynthesis pathway resulted in the production of the alkanes tridecane, pentadecane, and heptadecane. Our study provides a proof of principle for producing long-chain alkanes in the industrial workhorse S. cerevisiae, which was so far limited to bacteria. We anticipate that these findings will be a key factor for further yeast engineering to enable industrial production of alkane based drop-in biofuels, which can allow the biofuel industry to diversify beyond bioethanol.
在过去十年中，可再生运输生物燃料的工业规模生产已得到发展，作为化石燃料的替代品，乙醇是最突出的生物燃料，酵母是首选的生产生物体。然而，由于乙醇能量密度低，它作为重型运输、海上运输以及航空运输的替代燃料效率较低。因此，正在开发新型生物燃料，如烷烃，它们可用作直接替代燃料，能够替代汽油、柴油和煤油。在此，我们首次描述了酿酒酵母异源生物合成长链烷烃的过程。我们表明，消除十六碳烯醛脱氢酶Hfd1和表达一种氧化还原系统对于酵母中的烷烃生物合成至关重要。删除HFD1并表达烷烃生物合成途径导致了十三烷、十五烷和十七烷的产生。我们的研究为在工业主力菌株酿酒酵母中生产长链烷烃提供了原理证明，迄今为止这仅限于细菌。我们预计这些发现将是进一步进行酵母工程以实现基于烷烃的直接替代生物燃料工业化生产的关键因素，这可以使生物燃料行业超越生物乙醇实现多样化。
