Biosynthesis of Poly(3HB-co-3HP) with Variable Monomer Composition in Recombinant Cupriavidus necator H16

• DOI: 10.1021/acssynbio.1c00283
• Publication Date: 2021-11-12T00:48:35Z
• Authors: Callum McGregor; Nigel P. Minton; Katalin Kovács
• Keywords: Cupriavidus necator; Polyhydroxybutyrate

Polyhydroxyalkanoates are attractive alternatives to traditional plastics. However, although polyhydroxybutyrate (PHB) is produced in large quantities by Cupriavidus necator H16, its properties far from ideal for the manufacture of plastic products. These may be improved through coproduction with 3-hydroxypropionate (3HP), which leads formation copolymer poly(3-hydroxybutyrate-co-3-hydroxypropionate) (poly(3HB-co-3HP). To achieve this, a pathway was designed enable C. H16 convert β-alanine 3HP. The initial low levels incorporation 3HP into were overcome overproduction native propionyl-CoA transferase together PHA synthase Chromobacterium sp. USM2. Following optimization copolymer, molar fraction could controlled cultivation medium containing different concentrations β-alanine. Between 0 and 80 mol % achieved. Further supplementation 2 mM cysteine increased maximum 89%. Additionally, effect deletions phaA phaB1 genes phaCAB operon on investigated. A phaAB1 double knockout resulted 91 without need supplementation.