Protocol for obtaining polyhydroxyalkanoates from microbial cultures: Production, quantification, and analytical...

Area of Science:

• Biotechnology
• Polymer Science
• Microbial Engineering

Background:

• Polyhydroxyalkanoates (PHAs) are biodegradable biopolymers produced by bacteria.
• PHAs offer a sustainable alternative to conventional petroleum-based plastics.
• Efficient production methods are crucial for PHA commercialization.

Purpose of the Study:

• To present a comprehensive protocol for monitoring bacterial growth and PHA accumulation.
• To describe methods for achieving high cell-density cultures in bioreactors.
• To detail downstream processing and characterization of PHAs.

Main Methods:

• Utilized shaken flask cultures and benchtop bioreactors for bacterial cultivation.
• Employed two model organisms: Pseudomonas putida KT2440 and Cupriavidus necator H16.
• Included downstream processing for PHA isolation, monomer composition analysis, and thermal property determination.

Main Results:

• Achieved high biomass concentrations (6.5-7 g CDW/L) and PHA titers (4.2-4.5 g/L for P. putida; 3.5 g/L for C. necator).
• Established a reproducible protocol for PHA biopolymer production and characterization.
• Demonstrated the feasibility of scaling up PHA production using bioprocess engineering.

Conclusions:

• The presented protocol enables efficient monitoring and optimization of PHA production in bacteria.
• High cell-density cultures and optimized downstream processing are key for maximizing PHA yield.
• This work contributes to the development of sustainable bioplastics from bacterial sources.