Engineering photo-methylotrophic Methylobacterium for enhanced 3-hydroxypropionic acid production during non-growth stage fermentation

Bioresour Technol. 2024 Feb:393:130104. doi: 10.1016/j.biortech.2023.130104. Epub 2023 Nov 24.

Abstract

This study explored the potential of methanol as a sustainable feedstock for biomanufacturing, focusing on Methylobacterium extorquens, a well-established representative of methylotrophic cell factories. Despite this bacterium's long history, its untapped photosynthetic capabilities for production enhancement have remained unreported. Using genome-scale flux balance analysis, it was hypothesized that introducing photon fluxes could boost the yield of 3-hydroxypropionic acid (3-HP), an energy- and reducing equivalent-consuming chemicals. To realize this, M. extorquens was genetically modified by eliminating the negative regulator of photosynthesis, leading to improved ATP levels and metabolic activity in non-growth cells during a two-stage fermentation process. This modification resulted in a remarkable 3.0-fold increase in 3-HP titer and a 2.1-fold increase in its yield during stage (II). Transcriptomics revealed that enhanced light-driven methanol oxidation, NADH transhydrogenation, ATP generation, and fatty acid degradation were key factors. This development of photo-methylotrophy as a platform technology introduced novel opportunities for future production enhancements.

Keywords: Energy- and reducing equivalent-consuming chemicals; Methanol; Methylobacterium extorquens; Photo-methylotrophy; Two-stage fermentation.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Fermentation
  • Lactic Acid / analogs & derivatives*
  • Metabolic Engineering / methods
  • Methanol / metabolism
  • Methylobacterium* / genetics
  • Methylobacterium* / metabolism

Substances

  • hydracrylic acid
  • Methanol
  • Adenosine Triphosphate
  • Lactic Acid