Drop-in biofuel production using fatty acid photodecarboxylase from Chlorella variabilis in the oleaginous yeast Yarrowia lipolytica
Drop-in biofuel production using fatty acid photodecarboxylase from Chlorella variabilis in the oleaginous yeast Yarrowia lipolytica
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DOI：
10.1186/s13068-019-1542-4
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发表时间：
2019-08-24
影响因子：
6.3
通讯作者：
Kabisch, Johannes
中科院分区：
文献类型：
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作者：
Bruder, Stefan;Moldenhauer, Eva Johanna;Kabisch, Johannes
背景 产油酵母是可再生脂质生产的有效宿主，并且在生物燃料等衍生产品方面具有巨大潜力。已经描述了基于脂肪酸脱羧和脂肪醛脱羰生产碳氢化合物直接生物燃料的几种有前景的工艺。不幸的是，除了脂肪醛毒性和高反应性之外，研究最多的酶，醛脱甲酰化加氧酶，显示出不利的催化特性，阻碍了以前的代谢工程方法的高产率。结果为了证明产油酵母的替代烷烃生产途径，我们描述了通过在解脂耶氏酵母中异源表达最近发现的来自变量小球藻（CvFAP）的光驱动氧化酶来生产类似柴油的奇数链烷烃和烯烃。最初的实验表明，只有经过改造而具有更多游离脂肪酸的菌株才容易发生充分的脱羧。在合成培养基中向这些菌株提供葡萄糖和光，产生了 10.9 mg/L 的碳氢化合物滴度。使用用于照明生物反应器的定制 3D 打印实验室器具和自动脉冲甘油分批补料策略，实现了 58.7 mg/L 的细胞内滴度。先前研究中显示的长度为17和15个碳的奇数烷烃和烯烃的产生可以得到证实。结论 解脂耶氏酵母等产油酵母可以将甘油等可再生资源转化为脂肪酸和脂质。通过从藻类小球藻异源表达脂肪酸光脱羧酶，可以在从微孔板到 400 mL 生物反应器的多种规模中生产碳氢化合物。事实证明，照明是生长和碳氢化合物生产的关键因素，因此，对不同条件的评估是定制过程的重要一步。总的来说，所开发的生物工艺展示了一种可再生生产碳氢化合物的途径，可用于各种应用，包括作为进一步酶促或化学修饰的底物或作为直接生物燃料混合物。
Background Oleaginous yeasts are potent hosts for the renewable production of lipids and harbor great potential for derived products, such as biofuels. Several promising processes have been described that produce hydrocarbon drop-in biofuels based on fatty acid decarboxylation and fatty aldehyde decarbonylation. Unfortunately, besides fatty aldehyde toxicity and high reactivity, the most investigated enzyme, aldehyde-deformylating oxygenase, shows unfavorable catalytic properties which hindered high yields in previous metabolic engineering approaches. Results To demonstrate an alternative alkane production pathway for oleaginous yeasts, we describe the production of diesel-like, odd-chain alkanes and alkenes, by heterologously expressing a recently discovered light-driven oxidase from Chlorella variabilis (CvFAP) in Yarrowia lipolytica. Initial experiments showed that only strains engineered to have an increased pool of free fatty acids were susceptible to sufficient decarboxylation. Providing these strains with glucose and light in a synthetic medium resulted in titers of 10.9 mg/L of hydrocarbons. Using custom 3D printed labware for lighting bioreactors, and an automated pulsed glycerol fed-batch strategy, intracellular titers of 58.7 mg/L were achieved. The production of odd-numbered alkanes and alkenes with a length of 17 and 15 carbons shown in previous studies could be confirmed. Conclusions Oleaginous yeasts such as Yarrowia lipolytica can transform renewable resources such as glycerol into fatty acids and lipids. By heterologously expressing a fatty acid photodecarboxylase from the algae Chlorella variabilis hydrocarbons were produced in several scales from microwell plate to 400 mL bioreactors. The lighting turned out to be a crucial factor in terms of growth and hydrocarbon production, therefore, the evaluation of different conditions was an important step towards a tailor-made process. In general, the developed bioprocess shows a route to the renewable production of hydrocarbons for a variety of applications ranging from being substrates for further enzymatic or chemical modification or as a drop-in biofuel blend.