METHOD FOR PRODUCING MUCOID AND PHAGE RESISTANT GROUP N STREPTOCOCCUS STRAINS FROM NON-MUCOID AND PHAGE SENSITIVE PARENT STRAINS

摘要

ABSTRACT OF THE DISCLOSUREA method for imparting phage resistance to phagesensitive strains of Streptococcus group N is described.The method involves transferring plasmid encoding forproduction of a mucoid substance (Muc+) into the phagesensitive strain. Even if the Muc+ plasmid is removed bycuring at elevated temperatures the strains remainresistant to phage. The resulting resistant strains arenovel and are used for fermentations, particularly milkfermentations.