p-fluorophenylalanine-resistant mutants of starch-degrading bacillus polymyxa atcc 842 , generated by ethyl methanesulfonate mutagenesis followed by incubation with caffeine , overproduced small amounts of l-phenylalanine ( l-phe ) from starch .
C0030137
p-fluorophenylalanine
C0031453
phenylalanine