DefinePK

Abstract

Background:   Dextransucrase is an enzyme synthesized by many bacterial genera, which catalyzes the hydrolysis of sucrose to produce dextran, a polysaccharide with a wide range of medical, pharmaceutical, and industrial applications. The study aimed at isolating  Lactobacillus  species from the human vagina, assessing the production of dextransucrase, and determining the optimal growth conditions. Methods : A total of 53 bacterial samples were isolated from the reproductive tract of healthy women. Out of these 53 samples, 21 isolates of  Lactobacillus  spp. were obtained. Dextransucrase production was assessed using both the mucoid and spectrophotometric techniques. The effects of natural carbon, nitrogen sources, concentrations of nitrogen, protein, and sucrose, inoculum size, pH, temperature, and incubation time were evaluated to determine the optimal conditions. Results : The findings showing that  Lactobacillus acidophilus  isolates produced more dextransucrase than isolates of  Lactobacillus plantarum , with  Lactobacillus acidophilus  V19 being the strongest producer isolate due to its highest specific activity. The best conditions for producing dextransucrase were to use a dextransucrase production medium that underwent incubation at 37°C for 48 hours at pH 5.5, with a concentration of 6% sucrose, and 4% inoculum size. The most efficient source of nitrogen was 6% beef extract, and the best source of carbon was dates. At this point, the dextransucrase activity was at its highest. Conclusion : The findings of the study revealed that the optimal conditions for dextransucrase production are a pH of 5.5, 4% inoculum size, 6% dates extract as a carbon source, 6% beef extract as a nitrogen source, and 48 hours of incubation at 37°C. Keywords: Ecological; Optimization; Dextransucrase;  Lactobacillus acidophilus