Over the past decade, a sharp decline in worldwide honey bee population has been well documented. One of the causes of this population decrease has been the notorious bacterial honey bee pathogen, Paenibacillus larvae.
A consortium of German microbiologists and natural-product chemists, lead by Rolf Müller at the Helmholtz Centre of Infection Research and the Helmholtz Institute for Pharmaceutical Research, has discovered a group of antibiotic lipopeptides from cultures of P. larvae, for which the trivial names Paenilarvins is proposed. The paenilarvins belong to the iturin family and exhibited strong anti-fungal effects, as well as significant toxicity against honey bee larvae upon oral administration.
Paenilarvins are products of a non-ribosomal peptide synthetase (NRPS)/polketide synthase (PKS) hybrid gene cluster, which was predicted from a genome-mining analysis of the P. larvae genotype. Several other gene clusters putatively encoding for NRPS/PKS metabolites were also found but their products remain widely uncharacterized.
Recent genome-mining projects have revealed entomopathogenic bacteria with great potential for the production of new secondary metabolites. In nature, these compounds may act as, for example, virulence factors, means of defense against competing pathogens that are associated with the same host, or as signaling and regulatory molecules. However, these secondary metabolites are often not easily produced using standard laboratory methods. Future development of optimal growth and production conditions will allow for isolation of these compounds in sufficient quantities for their structure elucidation and biological characterization.
- Paenilarvins, Iturin Family Lipopeptides from the Honey Bee Pathogen Paenibacillus larvae,
S. Sood, H. Steinmetz, H. Beims, K. I. Mohr, M. Stadler, M. Djukic, W. von der Ohe, M. Steinert, R. Daniel, R. Müller,
Also of interest:
- Hope for the Honey Bee?,
Angewandte Chemie International Edition,
ChemViews Mag. 2014.