title: Plasmid Profiles of Lactose-Negative and Proteinase-Deficient Mutants of Streptococcus lactis C10, ML(3), and M18.
abstract: Lactose- and proteinase-negative (Lac Prt) mutants of Streptococcus lactis C10, ML3, and M18 were isolated after treatment with ethidium bromide. The Lac Prt mutants of C10 were missing a 40-megadalton plasmid. A 33-megadalton plasmid was absent in the ML3 mutants, and the M18 variants lacked a 45-megadalton plasmid. The results suggest a linkage of these metabolic traits to the respective plasmids. The possible complexity of the interrelationship between lactose metabolism and proteinase activity is presented.
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, St. Paul, Minnesota 55108.
authors.forename: S A
authors.initials: SA
authors.lastname: Kuhl
authors.forename: L D
authors.initials: LD
authors.lastname: Larsen
authors.forename: L L
authors.initials: LL
authors.lastname: McKay