title: Improving furfural tolerance of Zymomonas mobilis by rewiring a sigma factor RpoD protein.
abstract: Furfural from lignocellulosic hydrolysates is the key inhibitor for bio-ethanol fermentation. In this study, we report a strategy of improving the furfural tolerance in Zymomonas mobilis on the transcriptional level by engineering its global transcription sigma factor (σ(70), RpoD) protein. Three furfural tolerance RpoD mutants (ZM4-MF1, ZM4-MF2, and ZM4-MF3) were identified from error-prone PCR libraries. The best furfural-tolerance strain ZM4-MF2 reached to the maximal cell density (OD600) about 2.0 after approximately 30 h, while control strain ZM4-rpoD reached its highest cell density of about 1.3 under the same conditions. ZM4-MF2 also consumed glucose faster and yield higher ethanol; expression levels and key Entner-Doudoroff (ED) pathway enzymatic activities were also compared to control strain under furfural stress condition. Our results suggest that global transcription machinery engineering could potentially be used to improve stress tolerance and ethanol production in Z. mobilis.
authors.affiliation: Biogas Institute of Ministry of Agriculture, Biomass Energy Technology Research Centre, Section 4-13, Renming Nanlu, Chengdu, 610041, People's Republic of China.
authors.forename: Fu-Rong
authors.initials: FR
authors.lastname: Tan
authors.forename: Li-Chun
authors.initials: LC
authors.lastname: Dai
authors.forename: Bo
authors.initials: B
authors.lastname: Wu
authors.forename: Han
authors.initials: H
authors.lastname: Qin
authors.forename: Zong-Xia
authors.initials: ZX
authors.lastname: Shui
authors.forename: Jing-Li
authors.initials: JL
authors.lastname: Wang
authors.forename: Qi-Li
authors.initials: QL
authors.lastname: Zhu
authors.forename: Qi-Chun
authors.initials: QC
authors.lastname: Hu
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Ruan
authors.forename: Ming-Xiong
authors.initials: MX
authors.lastname: He
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D005285:Fermentation; D005662:Furaldehyde / Q000378:metabolism*; D005818:Genetic Engineering; D012808:Sigma Factor / Q000235:genetics* / Q000378:metabolism*; D017355:Zymomonas / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor; D005662:Furaldehyde