Anaerobic Production of Isoprene by Engineered Methanosarcina Species Archaea
Anaerobic Production of Isoprene by Engineered Methanosarcina Species Archaea
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DOI：
10.1128/aem.02417-20
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发表时间：
2021-03-01
影响因子：
4.4
通讯作者：
Buan, Nicole R.
中科院分区：
文献类型：
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作者：
Aldridge, Jared;Carr, Sean;Buan, Nicole R.
异戊二烯是一种有价值的石化产品，用于各种消费品，如粘合剂和合成橡胶。我们能够通过利用厌氧产甲烷古菌（产甲烷菌）中天然高通量甲羟戊酸脂质合成途径来实现可再生异戊二烯的高产率。我们的研究表明，通过遗传操纵甲烷八叠球菌属产甲烷菌，有可能创造出通过生产半萜异戊二烯而生长的生物体。质量平衡测量显示，工程化产甲烷菌将高达4%的总碳通量导向异戊二烯，表明产甲烷菌产生比工程化酵母、细菌或蓝细菌更高的异戊二烯产量，并且来自廉价的原料。异戊二烯合酶的表达导致生物量增加和基因表达的变化，这表明异戊二烯合成耗尽膜前体并重定向电子通量，使异戊二烯成为主要的代谢产物。我们的研究结果表明，产甲烷菌是一个很有前途的工程底盘可再生异戊二烯synthesize.IMPORTANCE实施可再生化工技术的一个重大障碍是相对于那些石油衍生产品的生产成本高。由于原料（如葡萄糖）、产品提取和纯化的成本，使用工程生物的现有技术难以与石油衍生化学品竞争。半萜单体异戊二烯就是这样一种化学品，目前无法使用具有成本竞争力的可再生生物技术生产。为了降低可再生异戊二烯的成本，我们已经改造了产甲烷菌，使其从廉价的原料如甲烷、甲醇、乙酸盐和二氧化碳中合成异戊二烯。我们开发的“异戊二烯原”菌株具有用于工业生产廉价的可再生异戊二烯的潜力。
Isoprene is a valuable petrochemical used for a wide variety of consumer goods, such as adhesives and synthetic rubber. We were able to achieve a high yield of renewable isoprene by taking advantage of the naturally high-flux mevalonate lipid synthesis pathway in anaerobic methane-producing archaea (methanogens). Our study illustrates that by genetically manipulating Methanosarcina species methanogens, it is possible to create organisms that grow by producing the hemiterpene isoprene. Mass balance measurements show that engineered methanogens direct up to 4% of total carbon flux to isoprene, demonstrating that methanogens produce higher isoprene yields than engineered yeast, bacteria, or cyanobacteria, and from inexpensive feedstocks. Expression of isoprene synthase resulted in increased biomass and changes in gene expression that indicate that isoprene synthesis depletes membrane precursors and redirects electron flux, enabling isoprene to be a major metabolic product. Our results demonstrate that methanogens are a promising engineering chassis for renewable isoprene synthesis.IMPORTANCE A significant barrier to implementing renewable chemical technologies is high production costs relative to those for petroleum-derived products. Existing technologies using engineered organisms have difficulty competing with petroleum-derived chemicals due to the cost of feedstocks (such as glucose), product extraction, and purification. The hemiterpene monomer isoprene is one such chemical that cannot currently be produced using cost-competitive renewable biotechnologies. To reduce the cost of renewable isoprene, we have engineered methanogens to synthesize it from inexpensive feedstocks such as methane, methanol, acetate, and carbon dioxide. The "isoprenogen" strains we developed have potential to be used for industrial production of inexpensive renewable isoprene.