High Ethanol Titers from Cellulose by Using Metabolically Engineered Thermophilic, Anaerobic Microbes

被引：220

作者：

Argyros, D. Aaron ^{[1
]}

Tripathi, Shital A. ^{[1
]}

Barrett, Trisha F. ^{[1
]}

Rogers, Stephen R. ^{[1
]}

Feinberg, Lawrence F. ^{[1
]}

Olson, Daniel G. ^{[1
,2
]}

Foden, Justine M. ^{[1
]}

Miller, Bethany B. ^{[1
]}

Lynd, Lee R. ^{[1
,2
]}

Hogsett, David A. ^{[1
]}

Caiazza, Nicky C. ^{[1
]}

机构：

[1] Mascoma Corp, Lebanon, NH 03766 USA

[2] Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA

来源：

APPLIED AND ENVIRONMENTAL MICROBIOLOGY | 2011年 / 77卷 / 23期

关键词：

CLOSTRIDIUM-THERMOCELLUM; SACCHAROMYCES-CEREVISIAE; GENE; FERMENTATION; EXPRESSION; BACTERIA; CELL; BIOFUELS; DELETION; CULTURES;

D O I：

10.1128/AEM.00646-11

中图分类号：

Q81 [生物工程学（生物技术）]; Q93 [微生物学];

学科分类号：

071005 ; 0836 ; 090102 ; 100705 ;

摘要：

This work describes novel genetic tools for use in Clostridium thermocellum that allow creation of unmarked mutations while using a replicating plasmid. The strategy employed counter-selections developed from the native C. thermocellum hpt gene and the Thermoanaerobacterium saccharolyticum tdk gene and was used to delete the genes for both lactate dehydrogenase (Ldh) and phosphotransacetylase (Pta). The Delta ldh Delta pta mutant was evolved for 2,000 h, resulting in a stable strain with 40:1 ethanol selectivity and a 4.2-fold increase in ethanol yield over the wild-type strain. Ethanol production from cellulose was investigated with an engineered coculture of organic acid-deficient engineered strains of both C. thermocellum and T. saccharolyticum. Fermentation of 92 g/liter Avicel by this coculture resulted in 38 g/liter ethanol, with acetic and lactic acids below detection limits, in 146 h. These results demonstrate that ethanol production by thermophilic, cellulolytic microbes is amenable to substantial improvement by metabolic engineering.

引用

页码：8288 / 8294

页数：7

共 34 条

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