Effect of Various Glucose Concentrations on Lactobacillus Species

Objective: The study aimed to determine the effect of various glucose concentrations on Lactobacillus species (Lacticaseibacillus rhamnosus isolated from pharmacy preparation, Lactiplantibacillus plantarum isolated from homemade whey, and standard probiotic bacteria Lactobacillus acidophilus ATCC 4356 and Lactiplantibacillus plantarum ATCC 14917). Materials and Methods: Probiotic bacteria were inoculated into De Man-Rogosa-Sharpe Broth (MRSB) media containing 2%, 4%, 8%, 16% and 32% glucose and incubated under aerobic conditions at 37°C for 3 days. The number of microorganisms per mL of the sample was determined by counting the number of colonies formed on the surface of the media. Results: L. rhamnosus isolated from pharmacy preparation increased at all glucose concentrations (2%, 4%, 8%, 16%, 32%) and L. acidophilus ATCC 4356 increased at all concentrations until the 55th hour. L. plantarum isolated from homemade whey continued to increase at the glucose concentrations of 2%, 4%, 8% and 32% until the 52nd hour. Similarly, L. plantarum ATCC 14917 strain continued its increase at 2%, 4%, 8% and 32% glucose concentrations until the 52nd hour. Additionally, both L. plantarum strains increased until the 53rd hour and then decreased at the 16% glucose concentration. Conclusion: Despite the increasing glucose concentrations (2%, 4%, 8%, 16% and 32%), the number of probiotic microorganisms in the present study have not significantly decreased.