Biosynthesis of polymalic acid in fermentation: advances and prospects for industrial application

Area of Science:

• Biotechnology and Bioprocessing
• Microbial Metabolism
• Polymer Science

Background:

• Poly(l-malic acid) (PMA) is a biopolymer with desirable properties like water solubility, biodegradability, and biocompatibility.
• PMA and l-malic acid have significant applications in pharmaceuticals, food, and biomedical fields.
• Current malic acid production relies on chemical synthesis, yielding a racemic mixture with safety concerns for the d-form.

Purpose of the Study:

• To review the biosynthesis of poly(l-malic acid) (PMA) by the black yeast Aureobasidium pullulans.
• To discuss metabolic engineering strategies and process optimization for enhanced PMA and l-malic acid production.
• To explore the potential of microbial production from renewable resources.

Main Methods:

• Analysis of metabolic and regulatory pathways involved in PMA biosynthesis.
• Review of metabolic engineering strategies for strain improvement.
• Discussion of fermentation process factors and downstream processing for PMA recovery.

Main Results:

• Aureobasidium pullulans possesses a large genome with genes for degrading plant materials, suitable for PMA production.
• Metabolic engineering and optimized fermentation conditions can enhance PMA and l-malic acid yields.
• Downstream processing methods are crucial for isolating and purifying PMA.

Conclusions:

• Microbial production of PMA and l-malic acid offers a sustainable alternative to chemical synthesis.
• Further research into metabolic pathways and strain development can optimize bioprocesses.
• Aureobasidium pullulans is a promising microorganism for the economical production of these valuable compounds.