Probiotic development for bees: analysing gut bacteria in healthy bees

Our previous RIRDC Project PRJ-00057 was the first study of bacteria in Australian honey bees. In that study, honeybee samples were collected from hives with different nutritional profiles from all Australian states and territories. In each state/territory, a minimum of ten hives in total from three apiaries were screened for bee gut bacteria. Australian honey bees in normal, healthy hives contained approximately 107 to 108 bacteria per gram of gut. In contrast, chalkbrood-diseased hives contained bees which had significantly less bacteria in their bee gut. Experiments tracking bacteria numbers in chalkbrood-infected hives showed that bacterial numbers return to normal when the hives lost all chalkbrood symptoms. The recovery from chalkbrood was significantly enhanced when the bees were fed sucrose solution. We found not only that a rich diversity of bacterial species inhabit the gut of healthy bees, but also that a proportion of bacteria are capable of inhibiting the chalkbrood pathogen. Candidate chalkbrood inhibiting bacterial from around Australia were stored. We demonstrated that bacteria can be (re)introduced in the bee gut through probiotic feeding. In this project, we propose to determine the feasibility of commercialising probiotics for bees. To do this, we need to obtain specific information on the fluctuation of bacterial numbers in bee guts over a year (including all four seasons). Then we will test a number of bacteria isolates with anti-fungal properties to determine the isolates with the greatest potential to be used in probiotics.