The subject invention relates to a low cost method of producing peptides, including antimicrobial peptides (AMPs), by using microbes. The subject methods enable greatly improved yields of the peptide/AMP as compared to those heretofore known in the art. The subject methods also surprisingly enable the use of Pseudomonas fluorescens to produce AMPs and other peptides. There are several components of the subject invention, which can be used alone or in combination. The subject invention provides for the production of peptides/AMPs in concatemeric precursors. The subject invention also provides novel methods of assembling monomers into multimers, and of cleaving the multimers to yield active monomers. The subject invention also relates to the use of these multimers fused to carrier peptides to produce fusion proteins. Preferably, both the multimers and the fusion proteins (multimers with the carrier polypeptides) lack charge balancing. It has been surprisingly determined that it is not necessary to offset the positive charges of multiple copies of AMPs in multimeric constructs. Thus, the subject invention enables the use of a wider range of multimers and carrier peptides.