Abstract:
Lactic acid bacteria are widely used as probiotics. Probiotics are beneficial components of the microbiota that have been used for centuries throughout the world because of the health benefits they confer to the host. Isolation and characterization of probiotic lactic acid bacteria is essential not only for understanding their individual contribution to fermentation processes but also to reveal their roles in industrial applications. The aim of this study was to isolate and characterize LAB from GIT of honeybee and further explore their potential for probiotic application. For this purpose, honeybees (Apis mellifera yementica) were collected from Apiculture of Haramaya University and private Apiculture of Dire Dawa district. Phenotypic characterization (Gram staining) of isolates identified 40 isolates for further evaluation. Results showed that, isolates were found to be gram positive, catalase negative, oxidase negative, non-motile, not responsible for H2S production and colony morphologies indicating they were likely to be lactic acid bacteria. All isolates were investigated for their probiotic potential. The result indicates that majority of isolates were exhibited excellent potential probiotic characteristics including homofermentative metabolic activity, ability to ferment different sugars, tolerant to 200C - 450C temperatures, 0.6% phenol concentration and 9% salt concentrations. In addition, isolates showed better adhesion properties towards xylene than they did towards chloroform. They were found to be highly acid tolerant at pH 3 for 3 h, survived at (0.3%) bile salt and 50% of them were resistant to the tested antibiotics, absence of gelatinase and hemolytic activity, showed strong inhibitory activity against S. Typhi (ATCC 27853) (17.67mm), S. aureus (ATCC 25923) (15.63mm), P. aeruginosa (ATCC 27353) (16.63mm) and E. coli 026:H11 (16.67mm) by HDB12, HDB12, HDB6 and HDB16 respectively, In general majority of the screened lactic acid bacteria have useful probiotic properties that make them innocent to use in different applications. Thus, based on the findings of this research further molecular characterization and in vivo tests be carried out to verify the probiotic properties of the isolates.
