Efficacy of barbital and p-hydroxymandelic acid on lactic acid bioproduction by LAB

The efficacy of barbital and p-hydroxymandelic acid on bioproduction of lactic acid by lactic acid bacteria such as Lactobacillus pentosus NCIM – 2669, Lactobacillus casei NCIM – 2732, Lactobacillus helveticus NCIM – 2737 and Lactobacillus plantarum NCIM –2592 has been assessed. It has been observed that the bacterial strain Lactobacillus casei NCIM – 2732 is most effective for the lactic acid fermentation process. It has been found that the compound, i.e., barbital at molar concentration 6.0 × 10 ^–5M enhances the bioproduction of lactic acid to an extent of 22.246% higher in comparison to control, i.e., 8.545g/100ml while at molar concentration 7.0×10 ^–5 M and onwards concentration of barbital under trial inhibits and retards the bioproduction of lactic acid when experimental parameters are under optimized condition, viz. 34°C temperature, 6.0 pH, 6 days incubation period with 20% (w/v) molasses solution. On the other hand when the compound, i.e; p-hydroxymandelic at molar concentration 4.0×10⁻⁵ M is incorporated in the same production medium it enhances the yield of lactic acid to an extent of 7.120% higher in comparison to control which is insignificant while at molar concentration 5.0×10⁻⁵ M and onwards of p-hydroxymandelic antagonises the lactic acid fermentation process thereby retards the yield of lactic acid.