A Study of Antimicrobial Effects of Reuterin by Lactobacillus reuteri DSM 17938 on Escherichia coli

Abstract: Background The widespread antibiotic resistance is an imminent problem in today’s world. As the number of antibiotic resistance cases increase, it is inevitable to discover alternate treatment options. Probiotics could be one of the potentially important avenues which could be exploited to treat antibiotic resistance and other infections. The holistic approach of probiotics in exerting their beneficial characteristics not only makes it an attractive member in this regard, but also in providing essential nutrients to the host. Results Lactobacillus reuteri DSM 17938 is one of the most commonly used probiotics and so, the production of antimicrobial reuterin (3-hydroxypropionaldehyde) by the conversion of glycerol and its antagonistic effects on E.coli C600 were studied by co-culturing the microorganisms. Different growth media and analytical techniques such as HPLC, flow-cytometry were used to determine the qualitative and quantitative results of the reuterin production and its activity on the co-cultures. The experiments revealed that glycerol alone does not exhibit an inhibitory property on E.coli, but a concentration of 5g/L induced the production of lethal amounts of reuterin in L.reuteri grown together with E.coli in SD4 medium with galactose. It was also found that glycerol concentrations beyond 10 g/L will lead to lethal doses of reuterin for L.reuteri too. Conclusion Thus, the work showed an optimal amount of glycerol concentration imparting antagonistic effect through the antimicrobial reuterin in co-cultures. Results Secondly, to study the exocellular electron transfer between two microorganisms, an attempt to design a modified reactor setup to explore the co-culturing possibilities was accomplished. The co-culturing possibilities of L.reuteri and Prevotella copri in Schaedler anaerobe broth yielded results that need to be studied in detail further. Conclusion More investigations are required to design a medium where both microorganisms can be adequately grown on.