Diversity of aerobic spore-forming bacteria isolated from fresh bee pollen intended for human consumption in Argentina

Abstract

Bee pollen is the result of the agglutination of pollen grains collected from flowers and mixedwith nectar and salivary secretions by honey bees. Bee pollen is a natural product exposed toenvironmental conditions and also provides a unique microhabitat for yeasts and bacterial communities. We analyzed 30 fresh bee pollen samples obtained from the main producing areas ofArgentina to identify aerobic-spore-forming bacteria. We obtained 73 isolates belonging to 16different species through isolation on selective and differential media, morphological and biochemical tests, and PCR and RFLP analysis of genes encoding 16S rRNA. Our data revealed thatBacillus cereus sensu stricto was the most predominant species (50%), followed by Bacillus megaterium (40%) and Bacillus subtilis (40%), respectively. In a minor proportion, Paenibacillus polymyxa (20%), Paenibacillus larvae (17%), Bacillus pumilus (13%), Bacillus licheniformis (13%),Bacillus amyloliquefaciens (10%), Lysinibacillus sphaericus (7%), Bacillus coagulans (7%),Rummelliibacillus stabekisii (7%), Bacillus thuringiensis (7%), Bacillus clausii (3%), Paenibacillus alvei(3%), Bacillus simplex (3%), and Paenibacillus amylolyticus (3%) were also found. Our resultsshowed that Argentinean bee pollen could transmit honey bee diseases due to the presence ofviable spores of P. larvae and also spores of toxicogenic B. cereus s.s. and B. megaterium strains.