Screening of Lactic Acid Bacteria from Poultry Droppings for Probiotic Potential

Abstract

Background: Globally, with the advent of industrial-scale intensification of poultry rearing, improved health and performance of chicken due to inclusion of sub-therapeutic levels of antibiotics in feeds have gained acceptance. The poultry industry has responded with development of probiotic, direct-fed microbials/prebiotic products. The probiotic bacteria supplemented in prevention dose had been reported to produce performance in poultry similar to antibiotics. Research has shown that among the probiotics, Lactobacillus species appears to be particularly stable and numerically significant in animal studies. Aim: The present study assesses screening of Lactic Acid Bacteria from Poultry Droppings for Probiotic Potential. Materials Methods: The study was conducted at the Microbiology Laboratory of Abubakar Tafawa Balewa University Bauchi, Bauchi state, Nigeria, between April to July, 2025. Faecal samples were collected from local chicken and enriched in buffered peptone water (Oxoid, UK) in a 1:10 sample to broth ratio at 37°C for 18 hours. 10g of freshly collected faeces were suspended separately in 90 ml of 1% peptone water (pH 3.5) for 2h at 37oC. Tenfold dilution was then carried out in sterile peptone water and appropriate dilutions of each sample pour plated in de Man Rogosa Sharpe (MRS) media (Oxoid, CM0359). The inoculated plates were then incubated at 37°C for 72 h. From each sample, 15–30 colonies were randomly selected and purified by streaking on MRS agar plates. Morphologically distinct colonies were purified by sub-culturing each 3 times in MRS Agar media (Oxoid, CM0359) plates until pure culture was obtained. Distinctive pure isolates obtained were sub-cultured in MRS agar slant and maintained at 4°C every 4 weeks. The isolates were further identified using the following biochemical test. Pure cultures of bacterial isolates were grown on MRS agar for 18hours. The rapid identification of different strains using the API 50 CH kit (Biomerieux. France) a standardized system was used to differentiate Lactic acid bacteria (LAB) isolates at strains level.  The potential probiotic bacteria strain was subjected to Bile salt resistance test, Tolerance to acidic pH, and Antibiotics sensitivity tests. Results: Lactobacillus brevis (10.00%), Lactobacillus fermentum (15.6%), Lactobacillus acidophilus (37.80%) and Lactobacillus plantarum (36.60%) were isolated and identified. Results after determining the probiotic properties of the isolates revealed that all isolates showed acceptable survival at acidic pH and tolerant to high concentration (1.0%) of bile salt hence they can survive the gastrointestinal tract. All of the isolated Lactobacillus species were also found to be resistant to streptomycin and kanamycin but sensitive towards tetracycline, ampicillin, and erythromycin. Probiotic properties of the isolates revealed that all isolates showed acceptable survival at acidic pH and tolerant to high concentration (1.0%) of bile salt hence they can survive the gastrointestinal tract. All of the isolated Lactobacillus species were also found to be resistant to streptomycin and kanamycin but sensitive towards tetracycline, ampicillin, and erythromycin. Conclusion: In this study, four Lactobacillus isolates from chicken droppings were found to have potential probiotic characteristics. These LAB strains are ideal probiotic candidates which can be used in vivo to increase poultry performance and for biocontrol of intestinal pathogens.