Production of polyhydroxyalkanoate copolymers containing 4-hydroxybutyrate in engineered Bacillus megaterium

Int J Biol Macromol. 2021 Jan 31:168:86-92. doi: 10.1016/j.ijbiomac.2020.12.015. Epub 2020 Dec 5.

Abstract

Despite being used as a common platform for the commercial production of many biochemicals, Bacilli are often overlooked as a source of industrial polyhydroxyalkanoates (PHAs), biodegradable plastic replacements. In addition to having a robust expression system, the lack of lipopolysaccharides and ease of lysis make Bacilli an attractive host for the production of PHAs. In this work, a Bacillus megaterium strain was engineered to generate poly(3-hydroxybutyrate-co-4-hydroxybutryate) (P[3HB-co-4HB]) copolymers, which are among the most useful and industrially-relevant copolymers. These copolymers had lower modulus and increased toughness, thus making the copolymer suitable for a broader range of applications. Due to high metabolic flux through succinate, the engineered B. megaterium strain produced P(3HB-co-4HB) with >10% mol fraction 4HB from glucose, without the use of highly regulated and expensive precursors or potentially damaging truncation of central biochemical pathways.

Keywords: 4-hydroxybutyrate; Bacillus megaterium; Biodegradable plastic; Polyhydroxyalkanoate copolymers.

MeSH terms

  • 3-Hydroxybutyric Acid / chemistry
  • Bacillus megaterium / metabolism
  • Cupriavidus / metabolism
  • Hydroxybutyrates / chemical synthesis
  • Hydroxybutyrates / metabolism*
  • Polyhydroxyalkanoates / biosynthesis*
  • Polyhydroxyalkanoates / metabolism*
  • Polymers / chemistry
  • Succinic Acid / metabolism
  • Xylose / chemistry
  • Xylose / metabolism

Substances

  • Hydroxybutyrates
  • Polyhydroxyalkanoates
  • Polymers
  • Xylose
  • Succinic Acid
  • 3-Hydroxybutyric Acid