Abstract: A topical, skin probiotic formulation comprises a living population of Corynebacterium glutamicum bacteria genetically-engineered to produce a skin-bioactive agent, and a nutrient source for the bacteria.

Abstract: Polyketide synthases are engineered to produce lactones. In the first module, an acyltransferase is swapped and in the second module a reductive loop is swapped. With another acyltransferase swap in the second module, we can programmably produce the non-methylated delta lactone.

Abstract: The present invention provides for a system comprising: (a) a first nucleic acid encoding an ?-factor receptor operatively linked to a first promoter, (b) a second nucleic acid encoding a recombinase operatively linked to a promoter which is activated by an ?-factor receptor bound to an ?-factor, and (c) a third nucleic acid encoding a gene of interest (GOI) flanked by a pair of recombinase recognition sequences, recognized by the recombinase, operatively linked to a second promoter. The present invention provides for a genetically modified fungal cell comprising the system of the present invention.