Consolidated bioprocessing of cassava starch into butyric acid and butanol by engineered Clostridium butyricum SCUT 620

Bioresour Technol. 2025 Feb:417:131870. doi: 10.1016/j.biortech.2024.131870. Epub 2024 Nov 23.

Abstract

Clostridium butyricum SCUT 620, a promising biorefinery chassis, has been demonstrated to efficiently utilize monosaccharides, disaccharides, and polysaccharides for butyric acid production. However, the absence of genetic manipulation tools has restricted its further development and application. For the first time, an efficient electroporation method for C. butyricum SCUT 620 was developed based on the analysis of the restriction-modification system and in vivo methylation. The highest electrotransformation efficiency reached 785 transformants/μg DNA after optimizing electroporation parameters. As a proof of concept, C. butyricum SCUT 620 was genetically modified to improve starch hydrolysis and butyrate tolerance, and to enable the synthesis of a new product, butanol, using non-grain biomass cassava starch. This study paves the way for the metabolic engineering of C. butyricum SCUT 620, with the objective of achieving various substrates utilization and chemicals production.

Keywords: Clostridia; Electroporation; Methylation; Non-food biomass; Restriction-modification system.

MeSH terms

  • Biotechnology / methods
  • Butanols* / metabolism
  • Butyric Acid* / metabolism
  • Clostridium butyricum* / metabolism
  • Electroporation / methods
  • Hydrolysis
  • Manihot* / metabolism
  • Metabolic Engineering / methods
  • Starch* / metabolism

Substances

  • Starch
  • Butyric Acid
  • Butanols