Journal of Food Research; Vol. 5, No. 5; 2016 ISSN 1927-0887 E-ISSN 1927-0895 Published by Canadian Center of Science and Education 77 Using Date Palm (Phoenix dactylifera L.) by-products to Cultivate Lactobacillus reuteri spp. Amira A. Ayad 1, 5 , Deiaa Gad El-Rab 2 , Abolghasem Shahbazi 3 , Mulumebet Worku 4 , Keith Schimmel 5 , Godfrey Ejimakor 6 , Tahl Zimmerman 1 , & Salam. A. Ibrahim 1 1 Food Microbiology and Biotechnology Laboratory, North Carolina A&T State University, USA 2 Dairy Science Department, National Research Center, Cairo, Egypt 3 Department of Chemical, Biological and Bioengineering, North Carolina A&T State University, USA 4 Department of Animal Sciences, North Carolina A&T State University, USA 5 Department of Energy & Environmental System, North Carolina A&T State University, USA 6 Department of Agribusiness, North Carolina A&T State University, USA Correspondence: Amira A. Ayad, Food Microbiology and Biotechnology Laboratory, Department of Energy & Environmental System, North Carolina A&T State University, Greensboro, NC 27403, USA. Tel: 336-549-3853. E-mail: aaayad@aggies.ncat.edu Received: April 28, 2016 Accepted: May 16, 2016 Online Published: August 27, 2016 doi:10.5539/jfr.v5n5p77 URL: http://dx.doi.org/10.5539/jfr.v5n5p77 Abstract 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 diH 2 O, 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. Keywords: bacterial population, cultivation, date palm extract, growth medium, lactic acid bacteria, phytone peptone 1. Introduction Lactic acid bacteria (LAB) are widely used in the fermentation of many food products such as meat, vegetables, beverages, dairy products. High cell mass production has become critical because many companies have developed an interest in LAB, not only as a starter culture, but also as a valuable probiotic additive to their food products (Barakat, Ibrahim, Tawfik, El-Kholy, & El-Rab, 2011). Lactobacilli are fastidious microorganisms that have numerous nutritional requirements for growth, including a need for nitrogen sources (Hayek, Shahbazi, Awaisheh, Shah, & Ibrahim, 2013). However, nitrogen sources are expensive and increase the cost of the growth media. The standard medium used to grow LAB is DeMan Rogosa Sharp (MRS). MRS is expensive and the industry needs a low-cost alternative. Food waste and agricultural by-products could be used as components of a low-cost media (Cotter & Hill, 2003). Large amount of by-products are generated during the processing of a variety of agricultural products. This waste includes fruit