A siderophore biosynthetic gene cluster was cloned from a metagenomic library generated from deep sea sediment. The gene cluster was successfully expressed in Escherichia coli to produce bisucaberin, a siderophore originally reported from the marine bacterium Alteromonas haloplanktis. The cloned bisucaberin biosynthetic gene cluster was moderately similar to that of the known bisucaberin producer Vibrio salmonicida. However, the cloned gene cluster consists of four genes rather than three genes found in the V. salmonicidacluster. The low overall homology of the amino acid and nucleotide sequences with those of other species suggests that the cloned genes were derived from one of the unsequenced bacteria including uncultured species.