Flocculation and coflocculation of bacteria by yeasts

Area of Science:

• Microbiology
• Biotechnology

Background:

• Microbial interactions are crucial for biotransformations.
• Interactions between bacteria are well-studied, but yeast-bacteria interactions remain less explored.
• Previous work demonstrated Saccharomyces cerevisiae inducing Pediococcus damnosus flocculation.

Purpose of the Study:

• To investigate the ability of various yeast species to induce flocculation in bacteria.
• To identify specific yeast strains that are effective inducers of bacterial flocculation.
• To explore the potential applications of these yeast-bacteria interactions.

Main Methods:

• Co-culturing of multiple yeast species (e.g., Candida utilis, Dekkera bruxellensis) with relevant bacteria (e.g., Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus).
• Observation and quantification of induced flocculation.
• Identification of highly effective yeast flocculation inducers.

Main Results:

• Several yeast species, beyond Saccharomyces cerevisiae, were found to induce bacterial flocculation.
• Candida utilis emerged as a particularly effective inducer of flocculation.
• Specific yeast strains demonstrated the ability to induce flocculation in industrially and medically significant bacteria.

Conclusions:

• Yeast-bacteria interactions, specifically yeast-induced bacterial flocculation, are more widespread than previously thought.
• Candida utilis shows promise as an inducer for microbial aggregation.
• These findings suggest novel applications for yeast-bacteria co-cultures in industrial processes and medicine.