Changes of pH by E. coli in water/sugar solution

[DKafkewitz]

E coli is known for its mixed acid fermentation. Formate, acetate, lactate
andsuccinate are prodcued in some combination. Unless you very vigorously
aerate to supress fermentation you will likely have a mix of aerobic and
anaerobic growth. 
Glucose and other sugars are non ionic and do not affect conductivity; acids
are ionic and do increase conductivity.