A novel NRPS cluster, acquired by horizontal gene transfer from algae, regulates siderophore iron metabolism in Burkholderia seminalis R456

In an environment with limited iron levels, sufficiently high intracellular iron concentrations are critical for bacterial survival. When iron levels are low, many bacteria including those of the Burkholderia cepacia group secrete chemically diverse siderophores to capture Fe3+. The synthesis of the two main siderophores, ornibactin and pyochelin, is regulated in an iron concentration dependent manner via the regulator protein Fur. In this study, we identified a novel Nonribosomal Peptide Synthetase (NRPS) cluster in strain R456 of Burkholderia seminalis, a member of the B. cepacia group. We show that the NRPS cluster not only allows the production of a so-far undescribed siderophore, but is also required for ornibactin and pyochelin production as it is a crucial component in the signaling pathway targeting the global iron regulating effector Fur which regulates siderophore production. Furthermore, the NRPS cluster is also involved in cell motility and biofilm formation, both of which are directly dependent on iron concentration in various bacteria. Interestingly, our data suggests that this newly discovered NRPS cluster which regulates siderophore iron metabolism in bacteria was obtained by horizontal gene transfer from algae. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

In an environment with limited iron levels, bacteria secrete diverse siderophores to capture Fe3+ for survival. A novel Nonribosomal Peptide Synthetase (NRPS) cluster in Burkholderia seminalis was found to be involved in the production of a new siderophore and regulation of ornubactin and pyochelin, as well as cell motility and biofilm formation, which are dependent on iron concentration. This newly discovered NRPS cluster is suggested to have been obtained by horizontal gene transfer from algae.