FIG 4.

Sugar metabolism in L. delbrueckii subsp. bulgaricus. Black arrows, active enzyme reactions; red X, enzyme reaction inactivated by mutation; dotted black arrow, externalization of exopolysaccharide. The indicated genes are as follows: manLMNO, glucose/mannose PTS IIABCD; lacS, and lactose permease. PTS, phosphotransferase system; EPS, exopolysaccharide; PG, peptidoglycan; PEP, phosphoenolpyruvate; glu-6-P, glucose-6-phosphate; fru-6-P, fructose-6-phosphate; fru-B-P, fructose-1,6-biphosphate. (Inset) Green arrow, active genes; red arrow, inactive genes; manLMNO, glucose PTS IIABCD gene.