Pseudomonas putida as a platform for the synthesis of aromatic compounds

Area of Science:

• Biotechnology
• Synthetic Biology
• Microbial Engineering

Background:

• Aromatic compounds like l-phenylalanine, 2-phenylethanol, and trans-cinnamate are industrially significant.
• There is a growing demand for sustainable 'green' production methods to replace traditional chemical synthesis.
• Microbial cell factories present a promising alternative for the biosynthesis of these valuable compounds.

Purpose of the Study:

• To engineer the solvent-tolerant Pseudomonas putida DOT-T1E strain as a microbial cell factory for aromatic compound production.
• To enhance the production of l-phenylalanine and enable the biosynthesis of 2-phenylethanol and trans-cinnamate.
• To demonstrate the versatility of P. putida for producing a range of industrially relevant aromatic compounds.

Main Methods:

• Genetic modification of Pseudomonas putida DOT-T1E.
• Selection of random mutants resistant to toxic phenylalanine analogues.
• Deletion of genes involved in phenylalanine metabolism pathways.
• Overexpression of the feedback-insensitive pheAfbr gene.
• Introduction of genes for histidinol phosphate transferase, phenylpyruvate decarboxylase, alcohol dehydrogenase, and phenylalanine ammonia lyase.

Main Results:

• Engineered P. putida produced up to 1 g/L of l-phenylalanine.
• Introduction of specific genes enabled the production of 180 mg/L of 2-phenylethanol.
• Introduction of phenylalanine ammonia lyase resulted in the production of 200 mg/L of trans-cinnamate.
• The engineered strain demonstrated efficient biosynthesis of multiple aromatic compounds.

Conclusions:

• Pseudomonas putida is a viable and promising microbial cell factory for the sustainable production of l-phenylalanine and related aromatic compounds.
• Metabolic engineering strategies, including gene deletion and overexpression, are effective in enhancing microbial production.
• The introduction of heterologous genes expands the capability of P. putida for producing diverse valuable chemicals.