Methanotrophs mediated biogas valorization: Sustainable route to polyhydroxybutyrate production

Bioresour Technol. 2024 Jun:402:130759. doi: 10.1016/j.biortech.2024.130759. Epub 2024 Apr 29.

Abstract

This study explores the ability of methanotrophs to convert biogas into biopolymers, addressing H2S as a limitation in the utilization of biogas as a carbon source for bioconversion. Transcriptomic analysis was conducted to understand the growth and changes in the expression patterns of Type I and II methanotrophs under varying H2S concentrations. Results suggested that Type II methanotrophs can possess a native H2S utilization pathway. Both Type I and II methanotrophs were evaluated for their growth and polyhydroxybutyrate (PHB) production from biogas. Methylocystis sp. MJC1 and Methylocystis sp. OK1 exhibited a maximum biomass production of 4.0 and 4.5 gDCW/L, respectively, in fed-batch culture, aligning with the transcriptome data. Furthermore, Methylocystis sp. MJC1 produced 2.9 g PHB/L from biogas through gas fermentation. These findings underscore biogas-based biotechnology as an innovative solution for environmental and industrial challenges with further optimization and productivity enhancement research expected to broaden the potential in this field.

Keywords: Biopolymers; Gas fermentation; Methane; Transcriptomic analysis.

MeSH terms

  • Batch Cell Culture Techniques
  • Biofuels*
  • Biomass
  • Fermentation
  • Hydroxybutyrates* / metabolism
  • Methane / metabolism
  • Methylocystaceae / metabolism
  • Polyesters / metabolism

Substances

  • Biofuels
  • Hydroxybutyrates
  • Polyesters
  • Methane