Combination of the CRP mutation and ptsG deletion in Escherichia coli to efficiently synthesize xylitol from corncob hydrolysates.
Appl Microbiol Biotechnol
; 104(5): 2039-2050, 2020 Mar.
Article
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| MEDLINE
| ID: mdl-31950219
ABSTRACT
The biotechnology-based production of xylitol has received widespread attention because it can use cheap and renewable lignocellulose as a raw material, thereby decreasing costs and pollution. The simultaneous use of various sugars in lignocellulose hydrolysates is a primary prerequisite for efficient xylitol production. In this study, a ΔptsG and crp* combinatorial strategy was used to generate Escherichia coli W3110 strain IS5-dI, which completely eliminated glucose repression and simultaneously used glucose and xylose. This strain produced 164 g/L xylitol from detoxified corncob hydrolysates during a fed-batch fermentation in a 15-L bioreactor, which was 14.7% higher than the xylitol produced by the starting strain, IS5-d (143 g/L), and the xylitol productivity was 3.04 g/L/h. These results represent the highest xylitol concentration and productivity reported to date for bacteria and hemicellulosic sugars. Additionally, strain IS5-dG, which differs from IS5-dI at CRP amino acid residue 127 (I127G), was tolerant to the toxins in corncob hydrolysates. In a fed-batch fermentation experiment involving a 15-L bioreactor, IS5-dG produced 137 g/L xylitol from non-detoxified corncob hydrolysates, with a productivity of 1.76 g/L/h. On the basis of these results, we believe that IS5-dI and IS5-dG may be useful host strains for the industrial-scale production of xylitol from detoxified or non-detoxified corncob hydrolysates.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Xilitol
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Sistema de Fosfotransferasa de Azúcar del Fosfoenolpiruvato
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Proteína Receptora de AMP Cíclico
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Zea mays
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Proteínas de Escherichia coli
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Escherichia coli
Idioma:
En
Revista:
Appl Microbiol Biotechnol
Año:
2020
Tipo del documento:
Article