Microorganisms associated with stingless bees

Abstract

The highly diversified group of stingless bees presents an associated microbiota that is suspected to be responsible for transforming pollen to bee bread or for the formation of honey. These microorganisms may also play a role on honey maturation and the biochemical modification of stored honey. Relatively few bacteria are found in the nest, probably due to antibiotic substances in the nest materials and inhibitors produced by the bees themselves to avoid competitors. Nevertheless, Bacillus meliponotrophicus is found associated with Trigona and Melipona, and the relationship between the bacterial species and the bee is obligatory since the use of antibiotics/streptomycin in the food led to disappearance of the colony. Also Streptomyces and Lactobacillus species occur in nests and bee guts of various species of Trigona. Few molds, probably saprophytes, are found in association with bees, although there are reports of fungal spore collection by some Apis, Trigona, and Partamona species. Various new yeast species, associated with bees and related habitats, were described that belong to the clade Starmerella. The role of these yeasts is still unclear; however, studies showed that transformation of pollen to bee bread occurs via a fermentative process brought about by yeasts and other microorganisms. Further studies may prove that the microbiota of bee and bee nests may act as mutualists and bring nutritional and other benefits to the stingless bees they are associated with.