Bioprocess development for endospore production by Bacillus coagulans using an optimized chemically defined medium

Area of Science:

• Microbiology
• Biotechnology
• Probiotics

Background:

• Bacillus coagulans (B. coagulans) possesses desirable probiotic properties from Lactobacillus and endospore formation from Bacillus.
• Cultivating B. coagulans is challenging due to conflicting growth and sporulation metabolic states.
• The expanding probiotics market necessitates efficient production methods for microorganisms like B. coagulans.

Purpose of the Study:

• To develop a strain-specific bioprocess for B. coagulans that supports both growth and sporulation.
• To optimize cultivation conditions for enhanced sporulation efficiency.
• To demonstrate the scalability and robustness of the developed bioprocess.

Main Methods:

• Development of a modified chemically defined medium for B. coagulans cultivation.
• One-factor-at-a-time (OFAT) assays to investigate process parameters including temperature, agitation, and pH control.
• Transfer and optimization of the bioprocess from shake flask to bioreactor scale (1 L to 10 L), including Design of Experiments (DoE) for robustness validation.

Main Results:

• The optimized bioprocess achieved a sporulation efficiency of 80%-90% in the bioreactor.
• pH control in the bioreactor significantly improved sporulation efficiency by sevenfold compared to shake flasks.
• The bioprocess was successfully scaled up to a 10 L bioreactor, maintaining high sporulation efficiency (80%).

Conclusions:

• The developed strain-specific bioprocess effectively balances B. coagulans growth and sporulation.
• pH control is a critical factor for maximizing sporulation efficiency in bioreactor cultivation.
• The bioprocess is robust, scalable, and suitable for industrial application to meet the increasing demand for probiotics.