Culture of Lactic Acid Bacteria in Natural Environments Based on Dates

Abstract

Introduction: Lactic acid bacteria are used in the food industry and have restrictive criteria for probiotic potential. The most common growth media used for lactic acid bacteria is de Man, Rogosa, and Sharpe culture medium (MRS). Methods: In this study, three culture media were developed (date powder DP, date core DC and date core associated with lentils CL) based on locally available plant materials with a low market value to obtain a less expensive culture medium compared to the reference medium MRS for the growth of lactic acid bacteria. Four lactic strains were used (Lactobacillus acidophilus LbA-CECT4529, Lactobacillus plantarum LbP-CECT 748, Bifidobacterium animalis subsp lactis Bb12 and Bifidobacterium bifidum Bb 443). The growth and acidification kinetics of the tested strains were evaluated. The content sugar was determinate with HPLC. Results: All lactic bacteria were able to grow on all culture media, but the best results were obtained with MRS and DP media. No significant difference (p <0.05) was observed between DP and MRS medium. The consumption of sugars and proteins in the DP medium was good with all tested bacteria (70.87 to 81.96% and 71.42 to 80.90%, respectively). After the analysis of sugar content of DP medium before and after fermentation with high-performance liquid chromatography (HPLC), fructose was the only sugar detected (45.28µg/ml ± 0.24). After fermentation, 83% of fructose was consumed by Bb12. Conclusion: The present data allow us to conclude that date medium promotes the growth of lactic bacteria and can be considered as MRS standard medium substitute.