Synthetic biology has demonstrated significant potential in programming living microorganisms for various applications. However, current fermentation practices mainly focus on planktonic cells, while microbes in nature frequently change their lifestyles in response to environmental variations. There is a need for methods that regulate the bacterial life cycle and enable phase-specific gene expression to bridge this gap. 

This invention is a platform to control biofilm formation/dispersion and metabolite production. It enables both induction and dispersion of biofilm formation of Lactococcus lactis upon exposure to or deprivation of zinc. In dispersed state, bacteria will produce desirable byproducts. Further, the system contains a nisin response circuit which will also allow the production of the aforementioned byproducts in the biofilm state. Biofilm based fermentation alone has been displayed to increase fermentation efficiency and yield in ethanol fermentation, but a population which can transition between both free floating and biofilm state has yet to be implemented. This technology may be highly useful for producing fermented foods at a large scale, as increases in efficiency can result in more efficient utilization of resources.

Benefits

Controlled biofilm formation  for improved fermentation processes.

Publication

Kong, W., Qian, Y., Stewart, P.S. et al. De novo engineering of a bacterial lifestyle program. Nat Chem Biol 19, 488–497 (2023). https://doi.org/10.1038/s41589-022-01194-1 [2]