CHARACTERISTICS OF MICROCOCCI FROM THE SURFACE OF ROQUEFORT CHEESE

Five different Micrococcus spp. were isolated from the surface of Roqu efort cheese: M. roseus, M. sedentarius, M. lylae, M. luteus and M. va rians. During culture on synthetic medium these bacteria produced acet ic acid as the main volatile fatty acid and propanol as the main alcoh ol. On a complex medium these isolates synthesized additional volatile fatty acids. Studies were made of the effect of pH, of water activity adjusted with sodium chloride or sorbitol, and of temperature on grow th rates. All five isolates were inhibited at a pH lower than 5.5 and grew at temperatures from 4 degrees to 44 degrees C; they were halotol erant and multiplied at NaCl concentrations up to 20%, corresponding t o a water activity of 0.884.