Seven
strains of LAB, which showed excellent inhibition zone diameters
larger than 30mmon the growth of S. aureus (Table 1), were chosen
for study in lactic acid production and reduction of pH. All of them
were cultured in MRS broth including D-glucose (dextrose) 20 mg/
ml which was used as the carbon source. The strain LD219 was the
best for lactic acid production and pH reducting ability at 37 C for
48 h (Table 2). The homofermentative LAB converted more than
90% of glucose to lactate via the EmdemeMyerhoffeParnas (EMP)
pathway under anaerobic conditions. In this pathway, two molecules
of pyruvate and NADH are generated from one molecule of
glucose. The pyruvate generated acts as the endogenous final
electron acceptor for the oxidation of NADH catalyzed by lactate
dehydrogenase (LDH).
LAB can also use exogenous electron acceptors as well