Use of Natural Selection and Evolution to Develop New Starter Cultures for Fermented Foods.

The fermented foods industry is constantly seeking new starter cultures to deal with changing consumer preferences and new fermentation processes. New cultures can either be composed of strains isolated from nature or improved derivatives of existing isolates. A variety of techniques involving natural selection and evolution are available to enhance the performance of existing strains, including the isolation of mutants with desired properties, adaptive laboratory evolution, genome shuffling, and genome editing. Numerous examples of traits that can be improved are provided. These include resistance to bacteriophages; the secretion of glucose to increase sweetness; the production of vitamins, antifungal compounds, bacteriocins, texture, or aroma; enhancement of acidification rates and acid tolerance; and elimination of biofilm formation. Careful consideration is required to ensure the developed strains are suitable for the desired purpose, as some approaches may lead to regulatory concerns.