Cargando…

Engineering a wild-type diploid Saccharomyces cerevisiae strain for second-generation bioethanol production

BACKGROUND: The cost-effective production of second-generation bioethanol, which is made from lignocellulosic materials, has to face the following two problems: co-fermenting xylose with glucose and enhancing the strain’s tolerance to lignocellulosic inhibitors. Based on our previous study, the wild...

Descripción completa

Detalles Bibliográficos
Autores principales: Li, Hongxing, Shen, Yu, Wu, Meiling, Hou, Jin, Jiao, Chunlei, Li, Zailu, Liu, Xinli, Bao, Xiaoming
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer Berlin Heidelberg 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5122614/
https://www.ncbi.nlm.nih.gov/pubmed/27942436
http://dx.doi.org/10.1186/s40643-016-0126-4
_version_ 1782469612687851520
author Li, Hongxing
Shen, Yu
Wu, Meiling
Hou, Jin
Jiao, Chunlei
Li, Zailu
Liu, Xinli
Bao, Xiaoming
author_facet Li, Hongxing
Shen, Yu
Wu, Meiling
Hou, Jin
Jiao, Chunlei
Li, Zailu
Liu, Xinli
Bao, Xiaoming
author_sort Li, Hongxing
collection PubMed
description BACKGROUND: The cost-effective production of second-generation bioethanol, which is made from lignocellulosic materials, has to face the following two problems: co-fermenting xylose with glucose and enhancing the strain’s tolerance to lignocellulosic inhibitors. Based on our previous study, the wild-type diploid Saccharomyces cerevisiae strain BSIF with robustness and good xylose metabolism genetic background was used as a chassis for constructing efficient xylose-fermenting industrial strains. The performance of the resulting strains in the fermentation of media with sugars and hydrolysates was investigated. RESULTS: The following two novel heterologous genes were integrated into the genome of the chassis cell: the mutant MGT05196 (N360F), which encodes a xylose-specific, glucose-insensitive transporter and is derived from the Meyerozyma guilliermondii transporter gene MGT05196, and Ru-xylA (where Ru represents the rumen), which encodes a xylose isomerase (XI) with higher activity in S. cerevisiae. Additionally, endogenous modifications were also performed, including the overproduction of the xylulokinase Xks1p and the non-oxidative PPP (pentose phosphate pathway), and the inactivation of the aldose reductase Gre3p and the alkaline phosphatase Pho13p. These rationally designed genetic modifications, combined with alternating adaptive evolutions in xylose and SECS liquor (the leach liquor of steam-exploding corn stover), resulted in a final strain, LF1, with excellent xylose fermentation and enhanced inhibitor resistance. The specific xylose consumption rate of LF1 reached as high as 1.089 g g(−1) h(−1) with xylose as the sole carbon source. Moreover, its highly synchronized utilization of xylose and glucose was particularly significant; 77.6% of xylose was consumed along with glucose within 12 h, and the ethanol yield was 0.475 g g(−1), which is more than 93% of the theoretical yield. Additionally, LF1 performed well in fermentations with two different lignocellulosic hydrolysates. CONCLUSION: The strain LF1 co-ferments glucose and xylose efficiently and synchronously. This result highlights the great potential of LF1 for the practical production of second-generation bioethanol. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40643-016-0126-4) contains supplementary material, which is available to authorized users.
format Online
Article
Text
id pubmed-5122614
institution National Center for Biotechnology Information
language English
publishDate 2016
publisher Springer Berlin Heidelberg
record_format MEDLINE/PubMed
spelling pubmed-51226142016-12-09 Engineering a wild-type diploid Saccharomyces cerevisiae strain for second-generation bioethanol production Li, Hongxing Shen, Yu Wu, Meiling Hou, Jin Jiao, Chunlei Li, Zailu Liu, Xinli Bao, Xiaoming Bioresour Bioprocess Research BACKGROUND: The cost-effective production of second-generation bioethanol, which is made from lignocellulosic materials, has to face the following two problems: co-fermenting xylose with glucose and enhancing the strain’s tolerance to lignocellulosic inhibitors. Based on our previous study, the wild-type diploid Saccharomyces cerevisiae strain BSIF with robustness and good xylose metabolism genetic background was used as a chassis for constructing efficient xylose-fermenting industrial strains. The performance of the resulting strains in the fermentation of media with sugars and hydrolysates was investigated. RESULTS: The following two novel heterologous genes were integrated into the genome of the chassis cell: the mutant MGT05196 (N360F), which encodes a xylose-specific, glucose-insensitive transporter and is derived from the Meyerozyma guilliermondii transporter gene MGT05196, and Ru-xylA (where Ru represents the rumen), which encodes a xylose isomerase (XI) with higher activity in S. cerevisiae. Additionally, endogenous modifications were also performed, including the overproduction of the xylulokinase Xks1p and the non-oxidative PPP (pentose phosphate pathway), and the inactivation of the aldose reductase Gre3p and the alkaline phosphatase Pho13p. These rationally designed genetic modifications, combined with alternating adaptive evolutions in xylose and SECS liquor (the leach liquor of steam-exploding corn stover), resulted in a final strain, LF1, with excellent xylose fermentation and enhanced inhibitor resistance. The specific xylose consumption rate of LF1 reached as high as 1.089 g g(−1) h(−1) with xylose as the sole carbon source. Moreover, its highly synchronized utilization of xylose and glucose was particularly significant; 77.6% of xylose was consumed along with glucose within 12 h, and the ethanol yield was 0.475 g g(−1), which is more than 93% of the theoretical yield. Additionally, LF1 performed well in fermentations with two different lignocellulosic hydrolysates. CONCLUSION: The strain LF1 co-ferments glucose and xylose efficiently and synchronously. This result highlights the great potential of LF1 for the practical production of second-generation bioethanol. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40643-016-0126-4) contains supplementary material, which is available to authorized users. Springer Berlin Heidelberg 2016-11-24 2016 /pmc/articles/PMC5122614/ /pubmed/27942436 http://dx.doi.org/10.1186/s40643-016-0126-4 Text en © The Author(s) 2016 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
spellingShingle Research
Li, Hongxing
Shen, Yu
Wu, Meiling
Hou, Jin
Jiao, Chunlei
Li, Zailu
Liu, Xinli
Bao, Xiaoming
Engineering a wild-type diploid Saccharomyces cerevisiae strain for second-generation bioethanol production
title Engineering a wild-type diploid Saccharomyces cerevisiae strain for second-generation bioethanol production
title_full Engineering a wild-type diploid Saccharomyces cerevisiae strain for second-generation bioethanol production
title_fullStr Engineering a wild-type diploid Saccharomyces cerevisiae strain for second-generation bioethanol production
title_full_unstemmed Engineering a wild-type diploid Saccharomyces cerevisiae strain for second-generation bioethanol production
title_short Engineering a wild-type diploid Saccharomyces cerevisiae strain for second-generation bioethanol production
title_sort engineering a wild-type diploid saccharomyces cerevisiae strain for second-generation bioethanol production
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5122614/
https://www.ncbi.nlm.nih.gov/pubmed/27942436
http://dx.doi.org/10.1186/s40643-016-0126-4
work_keys_str_mv AT lihongxing engineeringawildtypediploidsaccharomycescerevisiaestrainforsecondgenerationbioethanolproduction
AT shenyu engineeringawildtypediploidsaccharomycescerevisiaestrainforsecondgenerationbioethanolproduction
AT wumeiling engineeringawildtypediploidsaccharomycescerevisiaestrainforsecondgenerationbioethanolproduction
AT houjin engineeringawildtypediploidsaccharomycescerevisiaestrainforsecondgenerationbioethanolproduction
AT jiaochunlei engineeringawildtypediploidsaccharomycescerevisiaestrainforsecondgenerationbioethanolproduction
AT lizailu engineeringawildtypediploidsaccharomycescerevisiaestrainforsecondgenerationbioethanolproduction
AT liuxinli engineeringawildtypediploidsaccharomycescerevisiaestrainforsecondgenerationbioethanolproduction
AT baoxiaoming engineeringawildtypediploidsaccharomycescerevisiaestrainforsecondgenerationbioethanolproduction