Metabolites from Microbial Cell Factories in Stingless Bee Nests

More than 600 species of stingless bees (Hymenoptera, Apidae, Meliponini) produce honey in cerumen pots, with greater diversity than unifloral honey studied for Apis mellifera. Exceptionally, 500 of them are Neotropical meliponines that evolved since the Late Cretaceous Period, the date of the oldest bee fossil Cretotrigona prisca. Microbes associated with stingless bees may have 80 mya-shared nests and traits. In this review, importance is given to the SB species, authorities, years, ethnic names, geographical distribution, and type locality, available for Neotropical (America) in a reference chapter, but scattered for Paleotropical (Africa and Indo-Malaysia/Australasia). A summary list of these microorganisms was tabulated with corresponding substrates for each SB, 3 actinomycetes, 22 bacteria, 38 filamentous fungi, and 40 yeasts. Not all of them reached species identification, phyla, 3 classes of a phylum, family, and genus level. In addition to the microbiota, gut microbiome, and metabolites identified and quantified in their pot-food, microbial cell factories have been slowly demonstrated or suspected in recent contributions from Australia, Brazil, Ecuador, Indonesia, Kenya, Malaysia, and Tanzania. Microbiology, food science, and genomics come together to illustrate a few metabolites: 1. Alcohols: Ethanol, glycerol, isoamylic. 2. Aliphatic organic acids (AOA): Acetic, gluconic, lactic, oxalic, succinic, tartaric. 3. Amino acids: Phenylalanine, proline, pyroglutamic acid. 4. Antibiotics: Meliponamycin A, B, recently discovered as microbial metabolites in Melipona scutellaris. 5. Diphenylether: Asterric acid, 6. Polyketide pigments: Monascin. 7. Phenolic acids: 3-Phenyllactic acid. 8. Polyols: 2,3-Butanediol. 9. Statins: Lovastatin. 10. Steroids: Ergosterol. 11. Sugars: Dihydroxyacetone, maltose, raffinose, trehalulose, turanose. 12. Surfactants. 13. Vitamins: Ascorbic acid. Microbial data was retrieved from two genera, 27 Neotropical, and 13 Paleotropical (eight African, three Australasian, two Indo-Malaysian) SB species. Metabolites were studied in four genera and 20 Neotropical SB species, and 12 Paleotropical species (7 African, 3 Australasian, 2 Indo-Malaysian). The Scaptotrigona genus, and seven Neotropical species, the African Paleotropical Axestotrigona ferruginea, the three Australasian, and the two Indo-Malaysian stingless bee species were studied by both approaches.