Recent progress towards industrial rhamnolipids fermentation: Process optimization and foam control.

Area of Science:

• Biotechnology
• Chemical Engineering

Background:

• Rhamnolipids are valuable biosurfactants with a growing global market.
• Current production methods using Pseudomonas aeruginosa achieve high yields but face challenges with severe foaming during fermentation.
• Foaming significantly inhibits scale-up and overall production efficiency.

Purpose of the Study:

• To investigate strategies for improving rhamnolipid mass production efficiency.
• To address and mitigate the issue of severe foaming during rhamnolipid fermentation.
• To evaluate the effectiveness of a stop valve in foam control and its impact on production.

Main Methods:

• Optimized fed-batch cultivation of Pseudomonas aeruginosa using vegetable oil as a carbon source.
• Implementation of a stop valve to manage foam during fermentation.
• Comparison of mechanical and chemical foam control methods, and their combinations.

Main Results:

• Rhamnolipid yields exceeding 70 g/L were achieved under optimized conditions.
• A stop valve was effective in breaking stable rhamnolipid foams, leading to significant improvements in production efficiency.
• The scale-up mechanism of the stop valve requires further investigation.

Conclusions:

• Foaming is a critical bottleneck in rhamnolipid fermentation that can be effectively managed.
• Mechanical foam control using a stop valve shows promise for enhancing rhamnolipid production efficiency.
• Combined chemical and mechanical approaches may offer superior foam resolution compared to single methods.