[Optimization of high-cell-density fermentation process for S-adenosyl-L-methionine production]

Area of Science:

• Biotechnology
• Microbial Fermentation
• Metabolic Engineering

Background:

• High-cell-density fermentation of Saccharomyces cerevisiae for S-adenosyl-L-methionine (SAM) production faces stability issues during the anaphase.
• Optimizing fermentation conditions is crucial for maximizing SAM yield and production efficiency.

Purpose of the Study:

• To enhance the fermentation stability of Saccharomyces cerevisiae for increased S-adenosyl-L-methionine (SAM) production.
• To identify optimal nutrient supplementation strategies for high-cell-density fermentation.

Main Methods:

• Investigated the impact of supplementing glucose feeding solution with diammonium hydrogen phosphate, sodium glutamate, and adenosine disodium triphosphate.
• Conducted four fed-batch cultures in a 5 L fermentor to assess different feeding strategies.
• Determined optimal conditions for SAM production based on dry cell weight and SAM yield.

Main Results:

• Optimal conditions involved adding 50 g pre-L-methionine and 10 g/L adenosine disodium triphosphate to the glucose feeding solution.
• Under optimal conditions, fermentation reached a dry cell weight of 180 g/L and a SAM yield of 17.1 g/L after 65.7 hours.
• The addition of specific nutrients significantly improved fermentation stability and SAM production.

Conclusions:

• The optimized feeding strategy effectively improved fermentation stability and significantly boosted SAM production in Saccharomyces cerevisiae.
• This study provides a viable method for enhancing industrial-scale SAM production through improved fermentation control.