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Construction of cellulose-utilizing Escherichia coli based on a secretable cellulase

BACKGROUND: The microbial conversion of plant biomass into value added products is an attractive option to address the impacts of petroleum dependency. The Gram-negative bacterium Escherichia coli is commonly used as host for the industrial production of various chemical products with a variety of s...

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Autores principales: Gao, Dongfang, Luan, Yaqi, Wang, Qian, Liang, Quanfeng, Qi, Qingsheng
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4600292/
https://www.ncbi.nlm.nih.gov/pubmed/26452465
http://dx.doi.org/10.1186/s12934-015-0349-7
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author Gao, Dongfang
Luan, Yaqi
Wang, Qian
Liang, Quanfeng
Qi, Qingsheng
author_facet Gao, Dongfang
Luan, Yaqi
Wang, Qian
Liang, Quanfeng
Qi, Qingsheng
author_sort Gao, Dongfang
collection PubMed
description BACKGROUND: The microbial conversion of plant biomass into value added products is an attractive option to address the impacts of petroleum dependency. The Gram-negative bacterium Escherichia coli is commonly used as host for the industrial production of various chemical products with a variety of sugars as carbon sources. However, this strain neither produces endogenous cellulose degradation enzymes nor secrets heterologous cellulases for its poor secretory capacity. Thus, a cellulolytic E. coli strain capable of growth on plant biomass would be the first step towards producing chemicals and fuels. We previously identified the catalytic domain of a cellulase (Cel-CD) and its N-terminal sequence (N20) that can serve as carriers for the efficient extracellular production of target enzymes. This finding suggested that cellulose-utilizing E. coli can be engineered with minimal heterologous enzymes. RESULTS: In this study, a β-glucosidase (Tfu0937) was fused to Cel-CD and its N-terminal sequence respectively to obtain E. coli strains that were able to hydrolyze the cellulose. Recombinant strains were confirmed to use the amorphous cellulose as well as cellobiose as the sole carbon source for growth. Furthermore, both strains were engineered with poly (3-hydroxybutyrate) (PHB) synthesis pathway to demonstrate the production of biodegradable polyesters directly from cellulose materials without exogenously added cellulases. The yield of PHB reached 2.57–8.23 wt% content of cell dry weight directly from amorphous cellulose/cellobiose. Moreover, we found the Cel-CD and N20 secretion system can also be used for the extracellular production of other hydrolytic enzymes. CONCLUSIONS: This study suggested that a cellulose-utilizing E. coli was created based on a heterologous cellulase secretion system and can be used to produce biofuels and biochemicals directly from cellulose. This system also offers a platform for conversion of other abundant renewable biomass to biofuels and biorefinery products.
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spelling pubmed-46002922015-10-11 Construction of cellulose-utilizing Escherichia coli based on a secretable cellulase Gao, Dongfang Luan, Yaqi Wang, Qian Liang, Quanfeng Qi, Qingsheng Microb Cell Fact Research BACKGROUND: The microbial conversion of plant biomass into value added products is an attractive option to address the impacts of petroleum dependency. The Gram-negative bacterium Escherichia coli is commonly used as host for the industrial production of various chemical products with a variety of sugars as carbon sources. However, this strain neither produces endogenous cellulose degradation enzymes nor secrets heterologous cellulases for its poor secretory capacity. Thus, a cellulolytic E. coli strain capable of growth on plant biomass would be the first step towards producing chemicals and fuels. We previously identified the catalytic domain of a cellulase (Cel-CD) and its N-terminal sequence (N20) that can serve as carriers for the efficient extracellular production of target enzymes. This finding suggested that cellulose-utilizing E. coli can be engineered with minimal heterologous enzymes. RESULTS: In this study, a β-glucosidase (Tfu0937) was fused to Cel-CD and its N-terminal sequence respectively to obtain E. coli strains that were able to hydrolyze the cellulose. Recombinant strains were confirmed to use the amorphous cellulose as well as cellobiose as the sole carbon source for growth. Furthermore, both strains were engineered with poly (3-hydroxybutyrate) (PHB) synthesis pathway to demonstrate the production of biodegradable polyesters directly from cellulose materials without exogenously added cellulases. The yield of PHB reached 2.57–8.23 wt% content of cell dry weight directly from amorphous cellulose/cellobiose. Moreover, we found the Cel-CD and N20 secretion system can also be used for the extracellular production of other hydrolytic enzymes. CONCLUSIONS: This study suggested that a cellulose-utilizing E. coli was created based on a heterologous cellulase secretion system and can be used to produce biofuels and biochemicals directly from cellulose. This system also offers a platform for conversion of other abundant renewable biomass to biofuels and biorefinery products. BioMed Central 2015-10-09 /pmc/articles/PMC4600292/ /pubmed/26452465 http://dx.doi.org/10.1186/s12934-015-0349-7 Text en © Gao et al. 2015 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. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research
Gao, Dongfang
Luan, Yaqi
Wang, Qian
Liang, Quanfeng
Qi, Qingsheng
Construction of cellulose-utilizing Escherichia coli based on a secretable cellulase
title Construction of cellulose-utilizing Escherichia coli based on a secretable cellulase
title_full Construction of cellulose-utilizing Escherichia coli based on a secretable cellulase
title_fullStr Construction of cellulose-utilizing Escherichia coli based on a secretable cellulase
title_full_unstemmed Construction of cellulose-utilizing Escherichia coli based on a secretable cellulase
title_short Construction of cellulose-utilizing Escherichia coli based on a secretable cellulase
title_sort construction of cellulose-utilizing escherichia coli based on a secretable cellulase
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4600292/
https://www.ncbi.nlm.nih.gov/pubmed/26452465
http://dx.doi.org/10.1186/s12934-015-0349-7
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