Lactic acid bacteria (LAB) are used by industry to produce fermented food products. The standard media used to cultivate LABs is DeMan Rogosa Sharp (MRS). However, it is expensive. Alternative low-cost media must be developed for industrial use. A good source for growth media components are by-products generated during the production of agricultural goods, such as dates. Our objective was to investigate the use of date by-products for cultivating Lactobacillus reuteri.

Date palm extract (DPE) was prepared by pressing fresh date fruits for one week and diluting 1:2 with diH₂O, centrifuging at 4696 x g and 4°C 25 min, and autoclaving the supernatant at 110°C for 15 min. An MRS-based buffer solution was added to DPE make a date palm medium (DPM). DPM was then enriched with various amounts phytone peptone (0, 0.2, 0.4, 0.6, and 0.8 %, w/v) . The enriched DPMs were used to cultivate three strains of Lactobacillus reuteri: DSM 20016, CF2-7F, and SD 2112. Our results showed that in the DPM minus phytone peptone, bacterial counts reached 3.18 ± 0.5 log CFU/mL. Addition of lower amounts of phytone peptone did not improve bacterial growth. However, DPM medium supplemented with 0.8% phytone peptone improved the bacterial counts, which reached 6.94 ± 0.1 log CFU/mL, similar to what was observed with MRS ( 7.90± 0.24 log CFU/mL). There was no significant difference in the growth of LAB in MRS and phytone peptone enriched media DPM (p > 0.05). Date by-products are potentially alternative low cost components of LAB growth media.