ruptured cells of streptococcus lactis c2 , s. cremoris ml 1 and a lactose-negative proteinase-negative ( lac-prt- ) mutant of s. lactis c2 ( lmo220 ) were fractionated into the soluble , particulate , and ribosome fractions by differential centrifugation .
C0007634
cells
C0035553
ribosome