Involved in the biosynthesis of 2-methyl-3-n-amyl-pyrrole (MAP), one of the terminal products involved in the biosynthesis of the red antibiotic prodigiosin (Pig). Catalyzes the oxidation of dihydro form of MAP (H2MAP) to yield MAP. Antibiotic biosynthesis; prodigiosin biosynthesis. Cells lacking this gene show a white phenotype and produce 4-hydroxy-2,2'-bipyrrole-5-carbaldehyde (HBC), 4- methoxy-2,2'-bipyrrole-5-carbaldehyde (MBC) and a dihydro form of MAP (H2MAP). Belongs to the flavin monoamine oxidase family.