Abstract: The present invention is directed to phenylalanine ammonia-lyase (PAL) produced by prokaryotes, wherein such prokaryotic PAL wherein the PAL variant has a greater phenylalanine-converting activity and/or a reduced immunogenicity as compared to a wild-type PAL. The invention thus provides compositions of bacterial PAL and biologically active fragments, mutants, variants and analogs thereof, as well as methods for the production, purification, and use of such compositions for therapeutic and industrial purposes.