Isolation and Characterization of Probiotic Strains from Fermented Dragon Fruit (Hylocereus spp.): A Potential Source of Functional Microbes

Introduction: Probiotics are live microorganisms that confer health benefits to the host when consumed in adequate amounts. Dragon fruit (Hylocereus spp.), known for its rich nutrient profile and antioxidant properties, has not been extensively studied as a source of probiotics. This research aims to isolate and characterize potential probiotic strains from naturally fermented dragon fruit, exploring their viability, antimicrobial properties, and potential for functional food applications. Methodology: Fermentation of dragon fruit was carried out at room temperature for 7 days. Samples were collected at regular intervals, and the microbial population was enriched using selective media. Isolation of distinct colonies was performed, followed by Gram staining and biochemical tests to preliminarily identify probiotic candidates. The isolated strains were then subjected to in vitro tests for acid and bile salt tolerance, as well as antimicrobial activity against common pathogens. Statistical Analysis: Data were statistically analyzed using one-way ANOVA to compare the probiotic characteristics of different isolated strains. A p-value of <0.05 was considered significant. The results were presented as mean standard deviation. Results:The study successfully isolated several probiotic strains from fermented dragon fruit, predominantly belonging to the Lactobacillus and Bifidobacterium genera.These strains exhibited significant acid and bile salt tolerance, with survival rates exceeding 80% in harsh gastrointestinal conditions simulated in vitro.