High molecular weight β-poly(L-malic acid) produced by A. pullulans with Ca²⁺ added repeated batch culture

Area of Science:

• Biotechnology
• Polymer Science
• Biochemistry

Background:

• β-Poly(malic acid) (PMLA) shows promise for medical and industrial applications.
• Optimizing PMLA molecular weight (Mw) is crucial for its performance.
• Understanding PMLA Mw variation during fermentation is key to process improvement.

Purpose of the Study:

• To investigate PMLA molecular weight (Mw) dynamics in batch culture.
• To identify strategies for enhancing PMLA Mw.
• To develop an efficient method for producing high-Mw PMLA.

Main Methods:

• Monitoring PMLA Mw during batch fermentation.
• Supplementing culture medium with exogenous Ca(2+) (0.1g/L CaCl2).
• Implementing repeated batch culture strategies with Ca(2+) addition.

Main Results:

• Exogenous Ca(2+) increased PMLA concentration by 11.38% and Mw by 26.3%.
• PMLA Mw peaked at 18.693 KDa during batch culture before decreasing.
• Repeated batch culture with Ca(2+) yielded a 84.4% increase in Mw (up to 19.51 kDa).

Conclusions:

• Ca(2+) supplementation is an effective strategy to increase PMLA Mw.
• Repeated batch fermentation enhances PMLA production and molecular weight.
• This approach offers an efficient route to high-quality, high-Mw PMLA.