RADIATION-RESISTANT, PIGMENTED COCCUS ISOLATED FROM HADDOCK TISSUE.

Davis, Norman S. (Massachusetts Institute of Technology, Cambridge), Gerald J. Silverman, and Edmund B. Masurovsky. Radiation-resistant, pigmented coccus isolated from haddock tissue. J. Bacteriol. 86:294-298. 1963.-An orange-brown, catalase-positive coccus was isolated from irradiated haddock. The new coccus was found to consist of rough and smooth strains as well as strains possessing appreciably less pigment. The smooth strain (248) was more radioresistant to gamma radiation than the rough strain, and at higher radiation doses was of comparable resistance to Micrococcus radiodurans. The less-pigmented strain was as radio-resistant as its parent strain (248). Although morphologically similar to other, but less-resistant, micrococci, the coccus differed by growing slowly on solid media, and was unable to grow in 7% salt. It was distinguished from M. radiodurans by being smaller in size and in being capable of reducing nitrate to nitrite and hydrolyzing gelatin.