Conversion of Nicotinamide to Nicotinic Acid by Bacteria Isolated from Meat

Nicotinic acid (NA) production in meat by bacterial contamination during storage at 10°C was studied. Eighty-eight isolates from 9 meat samples produced NA or consumed nicotinamide (NAA) in nutrient broth containing NAA after incubation at 35°C for 24 h. The ten strains among these isolates converted NAA to NA and another 8 strains consumed not only NAA but also NA after incubation at 10°C for 7 d. Strain B-1, which had the highest activity for converting NAA to NA, was identified as Enterobacter agglomerans by the dot blot DNA-DNA hybridization method as well as by ordinary methods ; other strains identified were Enterobacteriaceae, Pseudomonas spp., Yersinia intermedia, Serratia liquefaciens and Aeromonas sp. NAA was converted to NA with an increase in bacterial counts in sterile meat which had been inoculated with strain B-1, whereas no NA or bacterial counts in sterile meat were detectable during storage at 10°C. These results confirm that contaminating bacteria were involved in NA production in meat during storage at 10°C.