Micro-Beads Building Trophic Networks for Gut Microbial Biotherapeutic Production

Christophe Lacroix of ETH Zürich in Switzerland will develop a new method to grow mixed strains of bacteria in bioreactors more efficiently and at lower cost for producing microbial-based biotherapeutics by immobilizing the bacteria on porous polysaccharide gel beads. Damage to the naturally-occurring bacterial populations in the human gut often occurs as a result of malnutrition and can cause serious illness. Healthy populations may be restored by gut microbial biotherapeutics – the ingestion of mixtures of naturally-occurring gut bacteria. Traditional processes to manufacture these mixtures is complex and expensive because many strains have strict growth requirements and do not grow well in mixed culture. They will immobilize bacteria on microbeads to allow multiple strains of bacteria to grow in the same culture: antagonistic strains will be spatially separated, less competitive strains will be maintained, and diversity will be preserved. Using inoculums from healthy human adults, they will optimize individual components of the system including the composition of the bacterial mixture, method of immobilization, and fermentation conditions within a continuous-culture stirred-tank reactor. The result will be the controlled, reproducible and efficient production of gut microbial biotherapeutics.