There is provided a method of producing at least one unsaturated amino acid from at least one amino acid comprising at least two carbonyl groups, the method comprising (a) contacting a recombinant microbial cell with a medium comprising the amino acid comprising the carbonyl groups, wherein the cell is genetically modified to compriseat least a first genetic mutation that increases the expression relative to the wild type cell of an enzyme (E) selected from the CYP152 10 peroxygenase family, andat least a second genetic mutation that increases the expression relative to the wild type cell of at least one NAD(P)+ oxidoreductase (E2) and the corresponding mediator protein.

The present invention provides a microbial cell capable of producing at least one terminal alkene from at least one short chain fatty acid, wherein the cell is genetically modified to comprise at least a first genetic mutation that increases the expression relative to the wild type cell of an enzyme (E.sub.1) selected from the CYP152 peroxygenase family, and at least a second genetic mutation that increases the expression relative to the wild type cell of at least one NAD(P)+ oxidoreductase (E.sub.2) and the corresponding mediator protein, wherein the short chain fatty acid is a C4-C10 fatty acid.