MASS CULTURE OF A SLIME MOLD, PHYSARUM POLYCEPHALUM

Area of Science:

• Biotechnology
• Mycology
• Cell Biology

Background:

• Physarum polycephalum is a unique eukaryotic organism with potential biotechnological applications.
• Cultivating slime molds on a large scale presents challenges due to their specific growth requirements.
• Previous research has focused on laboratory-scale cultivation, limiting industrial potential.

Purpose of the Study:

• To establish optimal conditions for pilot-plant scale fermentation of Physarum polycephalum.
• To determine achievable yields of Physarum polycephalum biomass in large-scale bioreactors.
• To address the challenges of aeration and aseptic technique in large-scale slime mold cultivation.

Main Methods:

• Cultivation of Physarum polycephalum in soluble natural medium.
• Use of shake flasks, 30-liter, and 50-gallon baffled fermentors for scale-up.
• Implementation of stringent aseptic techniques to prevent contamination.
• Modification of agitation rates to ensure adequate aeration without harming the organism.

Main Results:

• Achieved yields of 6 to 10 g (dry weight) per liter in large-scale fermentations.
• Identified the necessity for meticulous aseptic procedures due to slow growth rates.
• Demonstrated that standard high-agitation rates for aerobic fermentation are detrimental to Physarum polycephalum.
• Successfully adapted cultivation methods for pilot-plant scale production.

Conclusions:

• Pilot-plant scale fermentation of Physarum polycephalum is feasible.
• Optimized conditions allow for substantial biomass yields.
• Specific adaptations in aseptic technique and agitation are critical for successful large-scale cultivation of this myxomycete.