Three plasmids isolated from Lactobacillus helveticus ATCC 15009 were
analysed by restriction digestion. A restriction map of the 22.0, 6.0
and 3.5 kb plasmids is presented. The existence of genetic markers suc
h as carbohydrate fermentation, lactose metabolism, antibiotics and he
avy metal ions resistance was also investigated but the plasmids remai
n cryptic.