Growth kinetics and lactic acid production of Lactobacillus plantarum NRRL B-4496, L. acidophilus NRRL B-4495, and L. reuteri B-14171 in media containing egg white hydrolysates

Abstract

The objective of this study was to assess the performance of fermentation media containing egg white hydrolysates (EWH) and/or dried egg white (DEW) with standard MRS media on the growth of lactic acid bacteria (LAB) Lactobacillus plantarum NRRL B-4496, L. acidophilus NRRL B-449, and L. reuteri B-14171. Four fermentation media for growing LAB were evaluated: (1) standard MRS media, (2) MRS with no nitrogen source (MRSN), (3) MRSN with EWH (MRSN-EWH), and (4) MRSN with DEW (MRSN-DEW). The fermentation media were incubated with LAB at 37 °C for 24 h and periodically sampled to obtain growth curves, pH, and titratable acidity. The results showed that EWH had higher amounts of free amino acids compared to DEW. Threonine and leucine were the predominant free amino acids found in EWH. MRSN-EWH was better at promoting the growth of L. acidophilus NRRL B-449 and L. reuteri B-14171 in terms biomass production, maximum growth rate and titratable acidity than MRS. MRS and MRSN-EWH media supported greater cell biomass yields than MRSN and MRSN-DEW for L. plantarum NRRL B-4496. This study showed that egg white hydrolysates can be used in fermentation media to enhance the growth of probiotic lactic acid bacteria.