2,3-Butanediol production from cellobiose by engineered Saccharomyces cerevisiae
2,3-Butanediol production from cellobiose by engineered Saccharomyces cerevisiae
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DOI：
10.1007/s00253-014-5683-x
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发表时间：
2014-04
影响因子：
5
通讯作者：
H. Nan;S. Seo;E. Oh;Jin-Ho Seo;Jamie H. D. Cate;Yong‐Su Jin
中科院分区：
文献类型：
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作者：
H. Nan;S. Seo;E. Oh;Jin-Ho Seo;Jamie H. D. Cate;Yong‐Su Jin
从纤维素生物质生产可再生燃料和化学品是实现能源可持续性和减少温室气体排放的关键一步。微生物细胞已经被改造用于从纤维素糖生产化学品。在这些化学品中，2，3-丁二醇（2，3-BD 0）由于其不同的应用而成为感兴趣的化合物。虽然已经报道了具有高产率和生产率的2，3-BD 0的微生物生产，但是存在与潜在病原菌的利用和纤维素糖的低效利用相关的问题。为了解决这些问题，我们在酿酒酵母中设计了2，3-BDO的生产，特别是从纤维二糖，纤维素水解产物中普遍存在的糖。具体地说，我们从枯草芽孢杆菌中过量表达了SandalsD，以在工程化的纤维二糖发酵系统中通过α-乙酰乳酸和乙偶姻将丙酮酸转化为2，3-BDO。啤酒。在氧限制条件下，所得菌株能够产生2，3-BD 0。尽管如此，主要的碳流量还是流向了乙醇，导致大量乙醇作为副产品产生。为了通过消除丙酮酸脱羧反应来提高丙酮酸到2，3-BDO的通量，我们使用了PDC 1和PDC 5的缺失突变体来生产2，3-BDO。当在丙酮酸脱羧酶缺失突变体中引入由纤维二糖转运蛋白和细胞内β-葡糖苷酶组成的纤维二糖利用途径和2，3-BD 0产生途径时，所得菌株在氧限制条件下产生2，3-BD 0而不从纤维二糖产生乙醇。获得5.29g/l 2，3-BD 0的滴度，0.22g/l h的生产率和0.29g 2，3-BD 0/g纤维二糖的产率。这些结果表明从纤维素水解产物安全且可持续地生产2，3-BD 0的可能性。
Production of renewable fuels and chemicals from cellulosic biomass is a critical step towards energy sustainability and reduced greenhouse gas emissions. Microbial cells have been engineered for producing chemicals from cellulosic sugars. Among these chemicals, 2,3-butanediol (2,3-BDO) is a compound of interest due to its diverse applications. While microbial production of 2,3-BDO with high yields and productivities has been reported, there are concerns associated with utilization of potential pathogenic bacteria and inefficient utilization of cellulosic sugars. To address these problems, we engineered 2,3-BDO production inSaccharomyces cerevisiae, especially from cellobiose, a prevalent sugar in cellulosic hydrolysates. Specifically, we overexpressedalsSandalsDfromBacillus subtilisto convert pyruvate into 2,3-BDO via α-acetolactate and acetoin in an engineered cellobiose fermentingS. cerevisiae. Under oxygen-limited conditions, the resulting strain was able to produce 2,3-BDO. Still, major carbon flux went to ethanol, resulting in substantial amounts of ethanol produced as a byproduct. To enhance pyruvate flux to 2,3-BDO through elimination of the pyruvate decarboxylation reaction, we employed a deletion mutant of bothPDC1andPDC5for producing 2,3-BDO. When a cellobiose utilization pathway, consisting of a cellobiose transporter and intracellular β-glucosidase, and the 2,3-BDO producing pathway were introduced in a pyruvate decarboxylase deletion mutant, the resulting strain produced 2,3-BDO without ethanol production from cellobiose under oxygen-limited conditions. A titer of 5.29 g/l 2,3-BDO with a productivity of 0.22 g/l h and yield of 0.29 g 2,3-BDO/g cellobiose was attained. These results suggest the possibility of producing 2,3-BDO safely and sustainably from cellulosic hydrolysates.