Optimization of phenyllactic acid production by pediococcus acidilactici CRL 1753. Application of the formulated bio-preserver culture in breads

Abstract

Phenyl lactic acid (PLA) is an antimicrobial agent with a broad antimicrobial spectrumproduced mainly by lactic acidbacteria. This study focused in the optimization of a low-cost medium to obtain biomass and PLA production by Pediococcus (Ped.) acidilacticiCRL 1753 strain and propose its use as a liquid bio-preserver in bread makingto increase the shelf life of wheat bread. First, theactivity of CRL 1753 strain against filamentous fungi and yeastswas study and a wide antifungal inhibitory spectrum was observed. Using a factorial design 29-5 an optimized and low-cost medium (10 g/L meat peptone, 5 g/L yeast extract, 10 g/L glucose, 0.0038 g/L MnSO4, 6 g/L H3PO4 and initial pH = 7.0) that could replace MRSwas obtained. A significant increase in shelf life was observed when calcium propionate (CP) and CRL 1753 strain were combined into the bread formulation. In fact, at 18 days of storage none moulds were observed when the liquid bio-preserver was added while 70 % of bread were spoilage with CP alone.In this work we report for the first time the obtaining of an optimized low-cost culture medium for biomass and PLA production by Ped. acidilacticistrain.Additionally, the ability of the bio-preserver to guarantee the microbiological safety of packed bread was demonstrated.The results obtained could be very useful as a basis to design new strategies that allow improve the PLA production at a low cost.