Microbial polyhydroxyalkanoate production from lignin by Pseudomonas putida NX-1

Area of Science:

• Microbiology and Biotechnology
• Biorefining and Biomaterials

Background:

• Lignin valorization via biological methods is crucial but underexplored.
• Pseudomonas putida NX-1 harbors potential lignin-degrading enzymes.
• Polyhydroxyalkanoates (PHAs) are biodegradable polymers with diverse applications.

Purpose of the Study:

• To systematically identify and characterize ligninolytic enzymes in Pseudomonas putida NX-1.
• To investigate the potential of P. putida NX-1 for producing polyhydroxyalkanoates from lignin.
• To compare the properties of polyhydroxyalkanoates derived from lignin versus glucose.

Main Methods:

• Genome sequencing and analysis of Pseudomonas putida NX-1.
• Heterologous expression, purification, and enzymatic characterization of dye-decolorizing peroxidase.
• Cultivation of P. putida NX-1 using lignin as the sole carbon source.
• Analysis of polyhydroxyalkanoate properties using GC-MS, GPC, DSC, and TGA.

Main Results:

• A dye-decolorizing peroxidase from P. putida NX-1 showed activity on dyes and lignin derivatives.
• The bacterium successfully synthesized polyhydroxyalkanoates using lignin as the sole carbon source.
• Polyhydroxyalkanoates produced from lignin exhibited similar monomer composition, molecular weight, and thermal properties to those from glucose.

Conclusions:

• Ligninolytic enzymes in P. putida NX-1 were identified and characterized, including a versatile peroxidase.
• Lignin is a viable feedstock for producing polyhydroxyalkanoates with comparable quality to glucose-derived PHAs.
• This research supports lignin valorization for sustainable biopolymer production.