Engineering Pseudomonas chlororaphis HT66 for the Biosynthesis of Copolymers Containing 3-Hydroxybutyrate and Medium-Chain-Length 3-Hydroxyalkanoates.
Ru-Xiang DengHui-Ling LiWei WangHong-Bo HuXue-Hong ZhangPublished in: Journal of agricultural and food chemistry (2024)
Polyhydroxyalkanoates (PHAs) are promising alternatives to petroleum-based plastics, owing to their biodegradability and superior material properties. Here, the controllable biosynthesis of scl- co -mcl PHA containing 3-hydroxybutyrate (3HB) and mcl 3-hydroxyalkanoates was achieved in Pseudomonas chlororaphis HT66. First, key genes involved in fatty acid β-oxidation, the de novo fatty acid biosynthesis pathway, and the phaC1 - phaZ - phaC2 operon were deleted to develop a chassis strain. Subsequently, an acetoacetyl-CoA reductase gene phaB and a PHA synthase gene phaC with broad substrate specificity were heterologously expressed for producing and polymerizing the 3HB monomer with mcl 3-hydroxyalkanoates under the assistance of native β-ketothiolase gene phaA . Furthermore, the monomer composition of scl- co -mcl PHA was regulated by adjusting the amount of glucose and dodecanoic acid supplemented. Notably, the cell dry weight and scl- co -mcl PHA content reached 14.2 g/L and 60.1 wt %, respectively, when the engineered strain HT11Δ:: phaCB was cultured in King's B medium containing 5 g/L glucose and 5 g/L dodecanoic acid. These results demonstrated that P. chlororaphis can be a platform for producing scl- co -mcl PHA and has the potential for industrial application.
Keyphrases
- fatty acid
- copy number
- genome wide
- blood glucose
- heavy metals
- physical activity
- cell wall
- body mass index
- hydrogen peroxide
- escherichia coli
- metabolic syndrome
- wastewater treatment
- biofilm formation
- high throughput
- blood pressure
- type diabetes
- mass spectrometry
- skeletal muscle
- staphylococcus aureus
- molecularly imprinted
- bone marrow
- nitric oxide
- insulin resistance
- climate change
- visible light
- glycemic control