Engineering Pseudomonas putida for improved utilization of syringyl aromatics.

Area of Science:

• Biotechnology
• Synthetic Biology
• Microbial Engineering

Background:

• Lignin is an abundant, underutilized biopolymer resource.
• Pseudomonas putida KT2440 is a robust microorganism suitable for industrial bioprocessing.
• Efficient conversion of lignin-derived compounds is crucial for sustainable chemical production.

Purpose of the Study:

• To engineer Pseudomonas putida for the metabolic utilization of syringic acid, a key lignin derivative.
• To enhance the growth and efficiency of engineered P. putida strains on syringic acid.
• To identify genetic modifications enabling robust lignin valorization.

Main Methods:

• Rational metabolic engineering by overexpressing vanillate demethylase.
• Adaptive Laboratory Evolution (ALE) to select for improved syringic acid utilization.
• Genomic sequencing and reverse engineering of identified mutations.

Main Results:

• Engineered P. putida strain (Sy-1) demonstrated initial ability to metabolize syringic acid.
• ALE generated mutants with significantly improved growth rates on syringic acid.
• Genomic analysis identified key mutations in regulatory genes (agmR, gbdR, fleQ) and intergenic regions.

Conclusions:

• Pseudomonas putida can be effectively engineered to utilize syringic acid, a major lignin breakdown product.
• Genetic modifications identified through ALE enhance microbial growth and feedstock utilization.
• This work expands the potential of P. putida as a chassis for lignin-based bioproduction, improving economic viability.