Paenibacillus polymyxa Associated with the Stingless Bee Melipona scutellaris Produces Antimicrobial Compounds against Entomopathogens.

Social insects are frequently observed in symbiotic association with bacteria that produce antimicrobial natural products as a defense mechanism. There is a lack of studies on the microbiota associated with stingless bees and their antimicrobial compounds. To the best of our knowledge, this study is the first to report the isolation of Paenibacillus polymyxa ALLI-03-01 from the larval food of the stingless bee Melipona scutellaris. The bacterial strain was cultured under different conditions and produced (L)-(-)-3-phenyllactic acid and fusaricidins, which were active against entomopathogenic fungi and Paenibacillus larvae. Our results indicate that such natural products could be related to colony protection, suggesting a defense symbiosis between P. polymyxa ALLI-03-01 and Melipona scutellaris.