Benchmarking recombinant Pichia pastoris for 3-hydroxypropionic acid production from glycerol

Area of Science:

• Biotechnology
• Metabolic Engineering
• Industrial Microbiology

Background:

• Pichia pastoris is widely used for heterologous protein production, but its potential for bulk chemical synthesis is underexplored.
• 3-hydroxypropionic acid (3-HP) is a valuable platform chemical derived from glycerol, offering a sustainable alternative to petroleum-based products.

Purpose of the Study:

• To engineer Pichia pastoris as a cell factory for the production of 3-hydroxypropionic acid (3-HP) from glycerol.
• To enhance 3-HP production through metabolic engineering strategies.

Main Methods:

• Introduction of the malonate-CoA reductase (mcr) gene from Chloroflexus aurantiacus into P. pastoris.
• Metabolic and enzymatic engineering to optimize cofactor and precursor availability.
• Fed-batch cultivation of the engineered strain for high-density production.

Main Results:

• Successful production of 3-HP from glycerol via the malonyl-CoA pathway in P. pastoris.
• A 14-fold increase in 3-HP production achieved through strain engineering.
• The best strain (PpHP6) reached a final 3-HP concentration of 24.75 g/L, with a yield of 0.13 g/g and a volumetric productivity of 0.54 g/L/h.
• The achieved volumetric productivity is the highest reported for 3-HP production in yeast.

Conclusions:

• Pichia pastoris is a promising platform for the biotechnological production of bulk chemicals, including 3-HP.
• Engineered P. pastoris enables the valorization of crude glycerol into valuable chemicals.
• This study establishes a robust yeast-based system for sustainable 3-HP manufacturing.