Medium Chain Length Polyhydroxyalkanoate Production by Engineered Pseudomonas gessardii Using Acetate-formate as...

Area of Science:

• Microbiology
• Biotechnology
• Polymer Science

Background:

• Pseudomonas gessardii NIBRBAC000509957, isolated from South Korea, naturally produces polyhydroxyalkanoates (PHAs).
• The strain effectively utilizes acetate and formate as carbon sources, with optimal growth at 5 g/L acetate.
• Metabolic engineering can enhance the production of specific PHA types, such as medium chain length PHA (mcl-PHA).

Purpose of the Study:

• To optimize the production of mcl-PHA using Pseudomonas gessardii.
• To investigate the utilization of acetate and formate as carbon sources for enhanced microbial growth and PHA synthesis.
• To metabolically engineer the strain for increased mcl-PHA yield.

Main Methods:

• Isolation and characterization of Pseudomonas gessardii NIBRBAC000509957.
• Evaluation of acetate and formate utilization for bacterial growth.
• Overexpression of acetate and formate assimilation pathway enzymes.
• Metabolic engineering strategies to enhance mcl-PHA production.
• Fed-batch fermentation for mcl-PHA yield assessment.

Main Results:

• Optimal growth of Pseudomonas gessardii was observed at 5 g/L acetate.
• Overexpression of assimilation pathway enzymes significantly increased growth rate.
• The engineered strain produced 0.40 g/L of mcl-PHA.
• Achieved a biomass content of 30.43% mcl-PHA in fed-batch fermentation.

Conclusions:

• Pseudomonas gessardii can be metabolically engineered for efficient mcl-PHA production.
• Acetate and formate are viable carbon sources for enhancing microbial growth and biopolymer synthesis.
• The engineered strain holds potential for the sustainable production of valuable mcl-PHA from simple carbon sources.