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Bee pollen is a favorable microhabitat for many microorganisms and its dissemination via commercialization must be of important consideration. Here the data presented describe the characterization ...

Traditional mining activities are usually correlated with high levels of soil pollution, which is a major environmental concern. Extensive mining activities have taken place in the San Joaquin region in the State of Queretaro, Mexico resulting in high levels of mercury soil pollution (up to 1532 ± 300 mg/kg). We isolated mercury-resistant fungal strains from the San Joaquin region soils and identified them through morphologic characteristics and ITS rDNA region sequence analysis. We determined that fungi isolated belong to the genus Trichoderma. All the isolates selected showed the ability to catalyze the volatilization of Hg. For air sampling, an active sampling device was constructed and using acid KMnO4 as an absorbent, the concentration of mercury in solution was determined through the cold vapor atomic absorption method. The results show mercury volatilization from the fungal species assay, with a maximum of 213.04 ± 32.6 μg/m3 while mycelium accumulation ranged from less than 17.5 ± 2.9 to 20.0 ± 3.4 μg/g. The fungal isolates were also evaluated for their ability to reduce mercury uptake in Arabidopsis thaliana. These observations suggest the utility of Trichoderma for the mobilization of mercury in those contaminated soils.

American foulbrood (AFB) caused by Paenibacillus larvae is the most destructive honeybee bacterial disease and its dissemination via commercial bee pollen is an important mechanism for the spread of this bacterium. Because Mexico imports bee pollen from several countries, we developed a tRNA(Cys)-PCR strategy and complemented that strategy with MALDI-TOF MS and amplicon-16S rRNA gene analysis to evaluate the presence of P. larvae in pollen samples. P. larvae was not detected when the tRNA(Cys)-PCR approach was applied to spore-forming bacterial colonies obtained from three different locations and this result was validated by bacterial identification via MALDI-TOF MS. The genera identified in the latter analysis were Bacillus (fourteen species) and Paenibacillus (six) species. However, amplicon-16S rRNA gene analysis for taxonomic composition revealed a low presence of Paenibacillaceae with 0.3 to 16.2% of relative abundance in the commercial pollen samples analyzed. Within this family, P. larvae accounted for 0.01% of the bacterial species present in one sample. Our results indicate that the tRNA(Cys)-PCR, combined with other molecular tools, will be a useful approach for identifying P. larvae in pollen samples and will assist in controlling the spread of the pathogen.

Bee pollen is a highly nutritive natural foodstuff. Because of its use as a comestible, the association of bacteria with bee pollen is commercially and biologically important. We report here the bacterial diversity of seven bee pollen samples (five from Europe, one from Chile, and one from Mexico) based on 16S rRNA gene amplicon metagenome sequencing.