Use of a Tn5-based transposon system to create a cost-effective Zymomonas mobilis for ethanol production from lignocelluloses

Microbial Cell Factories

Research

Xianghui Jia¹  Haoyong Wang¹  Xi Zhang¹  Tianyv Wang²  Wen Zhou³ 

[1] Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Provincial Key Laboratory of Industrial Microbiology, College of Bioengineering, Hubei University of Technology, 430068, Wuhan, China;Nanhu Middle School, 430060, Wuhan, China;Zhejiang Hisun Pharmaceutical Co., Ltd., 318000, Taizhou, China;

关键词: Zymomonas mobilis;    Heat shock protein;    yfdZ;    metB;    Xylose fermentation;    Ethanol production;   

DOI  :  10.1186/1475-2859-12-41

 received in 2013-02-11, accepted in 2013-04-29,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundCurrent methods of ethanol production from lignocelluloses generate a mixture of sugars, primarily glucose and xylose; the fermentation cells are always exposed to stresses like high temperature and low nutritional conditions that affect their growth and productivity. Stress-tolerant strains capable of using both glucose and xylose to produce ethanol with high yield are highly desirable.ResultsA recombinant Zymomonas mobilis (Z. mobilis) designated as HYMX was constructed by integrating seven genes (Pfu-sHSP, yfdZ, metB, xylA, xylB, tktA and talB) into the genome of Z. mobilis CP4 (CP4) via Tn5 transposon in the present study. The small heat shock protein gene (Pfu-sHSP) from Pyrococcus furious (P. furious) was used to increase the heat-tolerance, the yfdZ and metB genes from E. coli were used to decrease the nutritional requirement. To overcome the bottleneck of CP4 being unable to use pentose, xylose catabolic genes (xylA, xylB, tktA and talB) from E. coli were integrated into CP4 also for construction of the xylose utilizing metabolic pathway.ConclusionsThe genomic integration confers on Z. mobilis the ability to grow in medium containing xylose as the only carbon source, and to grow in simple chemical defined medium without addition of amino acid. The HYMX demonstrated not only the high tolerance to unfavorable stresses like high temperature and low nutrient, but also the capability of converting both glucose and xylose to ethanol with high yield at high temperature. What’s more, these genetic characteristics were stable up to 100 generations on nonselective medium. Although significant improvements were achieved, yeast extract is needed for ethanol production.

【 授权许可】

Unknown   
© Zhang et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.