approximately 90% of the total lactic acid produced worldwide is by bacterial fermentation. Lactic acid is used as a substrate in the manufacture of polylactic acid (PLA), which could be a good substitute for synthetic plastic derived from petroleum feedstock (Zhou et al. 2006).
Table 3 shows the hydrogen peroxide produce by the LAB strains, the highest (0.35) was produced by L. fermentum LFBO1 at 36 hrs after incubation.
Table 4 shows the diacetyl produced by the isolates, it ranged within 0.91-1.92 (L. plantarum LPF2). The highest diacetyl was produced at 36 hrs of incubation. Reasonable quantity of dicaetyl was produced by the screened isolates. Diacetyl has a strong, buttery flavor and is essential at low concentrations in many dairy products, such as butter, buttermilk and fresh cheese.