Patent ID: 7846874

Claim:
A method for selecting cells comprising at least one metabolic pathway or metabolic pathway family enabling the transformation of a substrate {Ai} into a desired product {B}, comprising the following steps: a) providing a population of host cells (Ai−; B−) incapable of metabolizing said substrate {Ai} and said product {B}; b) transforming said population of host cells with a metagenomic library of nucleic acid sequences; c) testing the ability of said population of transformed host cells to grow on a minimum medium containing said substrate {Ai} selected from the group consisting of phytosterols, 1-phenyl-2-propanol and mandelonitrile as the only source of an element essential to growth and testing the ability of said population of transformed host cells to grow on another minimum medium containing said product {B} as the only source of an element essential to growth; and d) selecting said host cell(s) capable of growth on the minimum medium containing substrate {Ai} and on the minimum medium containing said product {B} so that the host cell(s) having a phenotype (Ai+; B+) is selected, and wherein host cell(s) having the phenotype (Ai+; B+) comprises metabolic pathway or metabolic pathway family enabling the transformation of at least one substrate {Ai} into the desired product [B}, and wherein i is a whole number between 1 and 100.