ABSTRACTLactic: acid bacteria (LAB) and various bacteria isolated from the environment were screened on microbiological media for the ability to convert brown metmyoglobin to more desirable bright red derivatives. Of 1,550 environmental isolates tested, two isolates (Kurthiasp. K‐22 andChromobacterium violaceumK‐28) were recovered which consistently converted metmyoglobin to more desirable color derivatives as characterized spectrophotometrically. Strains K‐22 and K‐28 produced oxymyoglobin and nitric oxide myoglobin, respectively. Of 347 LAB tested, one strain (Lactobacillus fermentumJCM1173) was identified that generated nitric oxide myoglobin. These data indicate certain bacteria can effectively convert metmyoglobin to more red forms, and establish the potential of bacterial systems for preserving or improving rhe color of meat p