The invention relates to a whole-cell catalyst which expresses a recombinant α-dioxygenase or the combination of a recombinant fatty acid reductase and a phosphopantetheinyl transferase which phosphopantetheinylates the fatty acid reductase, and which expresses, in addition to the α-dioxygenase and/or the combination of fatty acid reductase and phosphopantetheinyl transferase, a transaminase, wherein the phosphopantetheinyl transferase and/or transaminase is preferably recombinant; and also to a process for converting a carboxylic acid or dicarboxylic acid or a monoester thereof to an amine or diamine, comprising the steps of contacting the carboxylic acid or dicarboxylic acid or the monoester thereof with a phosphopantetheinylated fatty acid reductase or an α-dioxygenase and contacting the product with a transaminase.