Abstract 1306 Evaluation of the Effect of Lysine on the Microflora of Broiler Chickens by using Lactobacillus reuteri as an in vitro model

Mediation of gut flora diversity and composition by the utilization of amino acids may have additional effects on host metabolism and health, this may provide prospective development of nutritional approaches for disease prevention or treatment. Lysine is the second limiting amino acid needed for breast muscle development which makes it an essential feed-additive in poultry diets. Consequences for the lack of lysine have a profound effect on potassium concentrations and poor nitrogen retention in poultry. Previously, we have identified 18 species in the gut of chicken belonging to the Lactobacillaceae family. Lactobacillus reuteri a gut bacterium for human, chickens, and other mammals was selected as an in vitro model to investigate whether various concentrations of lysine may alter chicken gut microflora. Wild-type stain L. reuteri ATCC 55148 is the bacterial strain used as the in vitro test organism for this study. A basal media was formulated with all the ingredients that commercial MRS media contains, with decreased amounts to zero lysine being added to the media. L. reuteri ATCC 55148 was grown on basal media on agar plates at 37ºC for 24 hr. Lactobacillus reuteri's ability to thrive in various amounts of lysine in growth media has shown elimination of lysine or minimal amounts of lysine (0-0.14g) are not enough to sustain growth. Examining the nitrogen sources provided in the commercial MRS media, it was discovered that peptone, yeast extract and lab-lamco were the primary sources of nitrogen in the commercial media. L. reuteri lysine requirements were determined by the removal of peptone, yeast extract, and lab-lemco from the media will assess the amount of lysine that is in the media. L. reuteri ATCC 55148 was grown on basal media with or without the nitrogen sources within the agar plates at 37ºC for 24hr and l.reuteri growth was determined via plate counting. L. reuteri growth was the same as the commercial MRS when lab-lemco powder and peptone were individually absent from the growth media. However, collectively the removal of lab-lemco and peptone did not sustain l. reuteri growth and the same phenomena was observed with the removal of lab-lemco, peptone, and yeast extract. This preliminary work showcases the possible interaction within the gut bacteria environment as it pertains to growth requirements. Acknowledgements to the American Association of University Women (AAUW) for the Post Doctoral Fellowship personal and partial research funding and USDA NIFA grant number TENX-1518-GFSHPP.