Wild bees and their nests host Paenibacillus bacteria with functional potential of avail.
Keller A, Brandel A, Becker MC, Balles R, Abdelmohsen UR, Ankenbrand MJ, Sickel W
Microbiome. Dec 2018. doi: 10.1186/s40168-018-0614-1
COMMENT: The genus Paenibacillus includes severe bee pathogens but others are also found in the plant rhizosphere where they have beneficial effects on the plant host. This paper investigates whether the Paenibacillus species found in association with wild bees and their nests belong to the pathogenic strains or others with functional potential.
Authors screened solitary bee nests for occurrence of Paenibacillus with high-throughput sequencing-based 16S metabarcoding. They isolated a Paenibacillus strain with 100% 16S sequence identity for the full marker length of the 16S screening (V4) and sequenced its genome. In vitro bioassays were performed to confirm the bioactivity. They were interested in how this strain is related to known bee-virulent and plant-beneficial strains and performed a phylogenomic analysis together with all other publicly available genomes from the family Paenibacillaceae.
We found Paenibacillus to be a common, but irregularly occurring member of wild bee microbiomes and their nesting materials, although mostly in low relative abundance with respect to the whole microbiome.
We could distinguish 20 Paenibacillaceae operational taxonomic units (OTUs), including Paenibacillus, Cohnella, Aneurinibacillus, and Brevibacillus.
Using our phylogenomic approach, we were able to categorize the found Paenibacillus MBD-MB06 into a cluster of bacteria well-known to be able to produce such beneficial biofilms in plant-microbe interactions
The wild bee-associated Paenibacillus strain investigated here genomically was phylogenetically and functionally distinct from harmful members relevant to honey bee colony diseases.
Our strain showed strong anti-microbial capabilities and shows genomic potential for chitin-binding biofilm-forming, making it a useful associate to avoid fungal penetration of the bee cuticula and a beneficial inhabitant of nests.