Fermentations with new recombinant organisms
Fermentations with new recombinant organisms
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DOI：
10.1021/bp990087w
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发表时间：
1999-09-01
影响因子：
2.9
通讯作者：
Dien, BS
中科院分区：
文献类型：
--
作者：
Bothast, RJ;Nichols, NN;Dien, BS
美国1998年的燃料乙醇产量超过了1995年创下的14亿加仑的记录。其中大部分乙醇是由超过5.5亿蒲式耳的玉米生产的。扩大燃料乙醇生产将需要开发成本较低的原料，只有木质纤维素原料可获得足够的数量来替代玉米淀粉。将木质纤维素转化为乙醇的主要技术障碍包括缺乏用于将生物质糖化为可发酵糖的低成本有效的酶以及用于发酵这些混合糖的微生物的开发。迄今为止，开发有效发酵混合糖浆的肚脐生物催化剂的最成功的研究方法包括分离发酵木糖的新型酵母，大肠杆菌和其他革兰氏阴性菌用于乙醇生产的基因工程，以及酿酒酵母和运动发酵单胞菌用于戊糖利用的基因工程。我们已经评估了玉米纤维水解物的发酵所开发的各种菌株。E. coliK011、E. coli SL 40、E.大肠杆菌FBR 3、发酵单胞菌CP 4（pZB 5）和酵母菌1400（pLNH 32）发酵的玉米纤维水解成乙醇的范围为21-34 g/L，每克消耗的糖产率为0.41 - 0.50 g乙醇。新的重组微生物进展迅速，并将继续最终开发适合商业乙醇生产的微生物。每种研究方法都有相当大的希望，不同的“工业硬化”菌株可能会在特定原料的发酵中找到单独的应用。
United States fuel ethanol production in 1998 exceeded the record production of 1.4 billion gallons set in 1995. Most of this ethanol was produced from over 550 million bushels of corn. Expanding fuel ethanol production will require developing lower-cost feedstocks, and only lignocellulosic feedstocks are available in sufficient quantities to substitute for corn starch. Major technical hurdles to converting lignocellulose to ethanol include the lack of low-cost efficient enzymes for saccharification of biomass to fermentable sugars and the development of microorganisms for the fermentation of these mixed sugars. To date, the most successful research approaches to develop navel biocatalysts that will efficiently ferment mixed sugar syrups include isolation of novel yeasts that ferment xylose, genetic engineering of Escherichia coli and other gram negative bacteria for ethanol production, and genetic engineering of Saccharoymces cerevisiae and Zymomonas mobilis for pentose utilization. We have evaluated the fermentation of corn fiber hydrolyzates by the various strains developed. E. coli K011, E. coli SL40, E. coli FBR3, Zymomonas CP4 (pZB5), and Saccharomyces 1400 (pLNH32) fermented corn fiber hydrolyzates to ethanol in the range of 21-34 g/L with yields ranging from 0.41 to 0.50 g of ethanol per gram of sugar consumed. Progress with new recombinant microorganisms has been rapid and will continue with the eventual development of organisms suitable for commercial ethanol production. Each research approach holds considerable promise, with the possibility existing that different "industrially hardened" strains may find separate applications in the fermentation of specific feedstocks.