Figure 4
From: Lactobacillus delbrueckii ssp. lactis and ssp. bulgaricus: a chronicle of evolution in action
Lactose transport and metabolism pathways in L. delbrueckii and its ancestors. In L. delbrueckii ssp. bulgaricus, lactose uptake relies on a lactose-galactose antiporter which has been acquired by horizontal gene transfer while the ancestral lactose PTS system has been lost. L. delbrueckii ssp. lactis contains both transport systems. In L. delbrueckii ssp. bulgaricus, lactose metabolism relies on a Ī²-galactosidase which has been acquired by horizontal gene transfer while the ancestral Ī²-galactosidases have been lost. L. delbrueckii ssp. lactis contains the same horizontally acquired Ī²-galactosidase and, in addition, the pathways to completely metabolize lactose-6-P generated by the lactose PTS-system. PEP, phosphoenolpyruvate; Pyr, pyruvate.