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

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. Published by Elsevier B.V.

Automated summary

This study engineered a Bacillus megaterium strain to produce poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P[3HB-co-4HB]) copolymers, which are useful for various applications due to their lower modulus and increased toughness. The engineered strain was able to produce P(3HB-co-4HB) with >10% mol fraction 4HB from glucose, without the need for expensive precursors or damaging truncation of central biochemical pathways.