Engineering microbes for direct fermentation of cellulose to bioethanol

Abstract

Consolidated bioprocessing (CBP) by micro-organisms is desired for efficient conversion of lignocellulosic biomass to bioethanol fuels. Potential candidates have been discovered, including cellulolytic bacteria and filamentous fungi. Genetic and metabolic manipulation of these organisms further promotes their fermentation capacities and the ethanol tolerance. In addition, Saccharomyces cerevisiae and several other yeasts were genetically modified to express recombinant cellulases in media or display them on the cell surface for CBP of cellulose. To compensate the insufficient capacity of a single strain, various microbial consortia have also been developed. In this article, we reviewed the recent advances in CBP microbes and focused on the efforts in strain improvement employing genetic engineering.

Keywords:

• Cellulose
• bioethanol
• consolidated bioprocessing (CBP)
• Saccharomyces cerevisiae
• cellulase

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support of the Foundation of State Key Laboratory of Pulp and Paper Engineering [Nos. 2017QN01 and 2017PY01], the Fundamental Research Funds for the Central Universities [No. x2qsD2142050], the Guangdong Natural Science Foundation [No. 2017A030310341], and the Science and Technology Program of Guangzhou [No. 201704020038] is gratefully acknowledged.