DoE-based medium optimization for improved biosurfactant production with Aureobasidium pullulans.

Area of Science:

• Biotechnology
• Microbial Physiology

Background:

• Polyol lipids (liamocins) from Aureobasidium pullulans show promise as biosurfactants.
• Previous A. pullulans cultivations used complex media, hindering process optimization.

Purpose of the Study:

• Develop and optimize a defined minimal medium for enhanced polyol lipid production.
• Facilitate future research into A. pullulans metabolic pathways and genetic modification targets.

Main Methods:

• Replaced complex media components with vitamin and trace-element solutions and a nitrogen source.
• Utilized a design of experiments approach, including factorial screening and central composite design.
• Validated the optimized medium in microtiter plates and a 1L bioreactor.

Main Results:

• Achieved a 56% increase in polyol lipid titer to 48 g L⁻¹.
• Improved space-time yield from 0.13 to 0.20 g L⁻¹ h⁻¹.
• Reached 41 g L⁻¹ polyol lipid concentration in a 1L bioreactor.

Conclusions:

• The developed minimal medium supports high-yield polyol lipid production in A. pullulans.
• This defined medium is crucial for investigating alternative carbon sources and metabolic engineering strategies.
• The findings support the industrial applicability of A. pullulans as a robust biosurfactant producer.