SCI和EI收录∣中国化工学会会刊

›› 2016, Vol. 24 ›› Issue (8): 1074-1079.DOI: 10.1016/j.cjche.2016.04.004

• Biotechnology and Bioengineering • Previous Articles     Next Articles

Increasing isobutanol yield by double-gene deletion of PDC6 and LPD1 in Saccharomyces cerevisiae

Aili Zhang, Yang Li, Yuhan Gao, Hongxing Jin   

  1. School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, 300130, China
  • Received:2015-06-18 Revised:2016-01-27 Online:2016-09-21 Published:2016-08-28
  • Supported by:
    Supported by the National Natural Science Foundation of China (No. 21206028), the Doctoral Fund of Ministry of Education of China (No. 20121317120014), the Natural Science Foundation of Heibei Province (No. B2013202288), the Hebei Provincial Office of Education Science and Technology Research Projects (No. q2012024), the Hebei University of Technology Outstanding Youth Science and Technology Innovation Fund (No. 2012009) and the Open Fund of Key Laboratory of System Bioengineering of Ministry of Education of China (Tianjin University) (No. 20130315).

Increasing isobutanol yield by double-gene deletion of PDC6 and LPD1 in Saccharomyces cerevisiae

Aili Zhang, Yang Li, Yuhan Gao, Hongxing Jin   

  1. School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin, 300130, China
  • 通讯作者: Aili Zhang
  • 基金资助:
    Supported by the National Natural Science Foundation of China (No. 21206028), the Doctoral Fund of Ministry of Education of China (No. 20121317120014), the Natural Science Foundation of Heibei Province (No. B2013202288), the Hebei Provincial Office of Education Science and Technology Research Projects (No. q2012024), the Hebei University of Technology Outstanding Youth Science and Technology Innovation Fund (No. 2012009) and the Open Fund of Key Laboratory of System Bioengineering of Ministry of Education of China (Tianjin University) (No. 20130315).

Abstract: As a new biofuel, isobutanol has received more attentions in recent years. Because of its high tolerance to higher alcohols, Saccharomyces cerevisiae has potential advantages as a platform microbe to produce isobutanol. In this study, we investigated integration effects of enhancing valine biosynthesis by overexpression of ILV2 and BAT2 with eliminating ethanol formation by deletion of PDC6 and decreasing acetyl-CoA biosynthesis by deletion of LPD1 on isobutanol titers. Our results showed that deletion of LPD1 in strains overexpressing BAT2 and ILV2 increased isobutanol titer by 5.3-fold compared with control strain. Additional deletion of PDC6 in lpd1Δ strains carrying overexpressed BAT2 and ILV2 further increased isobutanol titer by 1.5 fold. Overexpression of BAT2 and ILV2 in lpd1Δ strains and pdc6Δ strains decreased ethanol titers. Glycerol titers of the engineered strains did not have greater changes than that of control strain, while their acetic acid titers were higher, perhaps due to the imbalance of cofactors in isobutanol synthesis. Our researches suggest that double-gene deletion of PDC6 and LPD1 in strains overexpressing BAT2 and ILV2 could increase isobutanol production dramatically than single-gene deletion of PDC6 or LPD1. This study reveals the integration effects of overexpression of ILV2/BAT2 and double-gene deletion of LPD1 and PDC6 on isobutanol production, and helps understanding future developments of engineered strains for producing isobutanol.

Key words: Saccharomyces cerevisiae, Isobutanol, Ethanol, Pyruvate decarboxylase

摘要: As a new biofuel, isobutanol has received more attentions in recent years. Because of its high tolerance to higher alcohols, Saccharomyces cerevisiae has potential advantages as a platform microbe to produce isobutanol. In this study, we investigated integration effects of enhancing valine biosynthesis by overexpression of ILV2 and BAT2 with eliminating ethanol formation by deletion of PDC6 and decreasing acetyl-CoA biosynthesis by deletion of LPD1 on isobutanol titers. Our results showed that deletion of LPD1 in strains overexpressing BAT2 and ILV2 increased isobutanol titer by 5.3-fold compared with control strain. Additional deletion of PDC6 in lpd1Δ strains carrying overexpressed BAT2 and ILV2 further increased isobutanol titer by 1.5 fold. Overexpression of BAT2 and ILV2 in lpd1Δ strains and pdc6Δ strains decreased ethanol titers. Glycerol titers of the engineered strains did not have greater changes than that of control strain, while their acetic acid titers were higher, perhaps due to the imbalance of cofactors in isobutanol synthesis. Our researches suggest that double-gene deletion of PDC6 and LPD1 in strains overexpressing BAT2 and ILV2 could increase isobutanol production dramatically than single-gene deletion of PDC6 or LPD1. This study reveals the integration effects of overexpression of ILV2/BAT2 and double-gene deletion of LPD1 and PDC6 on isobutanol production, and helps understanding future developments of engineered strains for producing isobutanol.

关键词: Saccharomyces cerevisiae, Isobutanol, Ethanol, Pyruvate decarboxylase