Use of Lactobacilli in Cereal-Legume Fermentation and as Potential Probiotics towards Phytate Hydrolysis

Phytate is a potent inhibitor of mineral absorption in humans occurring in plant-based food. Application of lactobacilli that produce phytate-degrading enzymes (phytases) to reduce phytate is an interesting yet a not much explored sector of research. Therefore, phytate dephosphorylation by Lactobacillus plantarum MTCC 1325 was evaluated. Cells at stationary phase showed phytase activity which was maximal at 24 h of growth. Glucose concentration and the type of phosphorous source in the media modulated the enzyme activity. Fermentation of cereal and/or legume flours with the strain resulted in phytate reduction with the highest in sorghum (73%) and the lowest in horse gram (34%). Further, the strain showed tolerance to acid, bile, and simulated gastrointestinal fluid. Significant phytase activity in the presence of simulated gastrointestinal fluids along with the ability to produce phytases post-exposure to simulated gastrointestinal fluids is of interest. To the best of our knowledge, this is the first report on the effect of simulated gastrointestinal fluid on cell-associated phytases of lactobacilli. The results of the investigation indicate that L. plantarum MTCC 1325 could be used as a starter in cereal-legume fermentation and as potential probiotics to achieve phytate hydrolysis in food matrices and also in gastrointestinal tract.