The evolution of three siderophore biosynthetic clusters in environmental and host-associating strains of Pantoea

Abstract

For many pathogenic members of the Enterobacterales, siderophores play an important role in virulence, yet the siderophores of the host-associating members of the genus Pantoea remain unexplored. We conducted a genome-wide survey of environmental and host-associating strains of Pantoea to identify known and candidate siderophore biosynthetic clusters. Our analysis identified three clusters homologous to those of enterobactin, desferrioxamine, and aerobactin that were prevalent among Pantoea species. Using both phylogenetic and comparative genomic approaches, we demonstrate that the enterobactin-like cluster was present in the common ancestor of all Pantoea, with evidence for three independent losses of the cluster in P. eucalypti, P. eucrina, and the P. ananatis-P. stewartii lineage. The desferrioxamine biosynthetic cluster, previously described and characterized in Pantoea, was horizontally acquired from its close relative Erwinia, with phylogenetic evidence that these transfer events were ancient and occurred between ancestral lineages. The aerobactin cluster was identified in three host-associating species groups, P. septica, P. ananatis, and P. stewartii, with strong evidence for horizontal acquisition from human-pathogenic members of the Enterobacterales. Our work identifies and describes the key siderophore clusters in Pantoea, shows three distinct evolutionary processes driving their diversification, and provides a foundation for exploring the roles that these siderophores may play in human opportunistic infections.

Comparison of five bacterial strains producing siderophores with ability to chelate iron under alkaline conditions

“…Due to the lack of information of the siderophores produced by P. allii and the results shown in Fig. 4, it is possible that the siderophores produced are not of the 1:1 type, as it is the case of enterobactin, desferrioxamine, and aerobactin, which were described for others species of Pantoea (Soutar and Stavrinides 2018). Nonetheless, in case of a 1:1 complexation, the complexed formed may not be very strong and, thus, not capable of complexing most iron added at pH 9.0.…”

Antimicrobial Activity Against Phytopathogens and Inhibitory Activity on Solanine in Potatoes of the Endophytic Bacteria Isolated From Potato Tubers

“…Pantoea showed the highest proportion in Group CK, Bacillus and Rhodococcus showed the highest proportion in Group H. In addition, Myroides and Polaromonas were only detected in Group L (Table 4). As the promising endophytic bacteria genera for agricultural practices, Pantoea and Bacillus have been extensively studied, which have the ability to dissolve inorganic phosphates, produce siderophores, inhibit the growth of plant pathogens, and produce indole-3-acetic acid (IAA) among others (Elshaghabee et al, 2017;Soutar and Stavrinides, 2018;Ferreira et al, 2019). The members of Rhodococcus are diverse catalysts that degrade a variety of both natural, organic, and xenobiotic compounds.…”

Promising bacterial genera for agricultural practices: An insight on plant growth-promoting properties and microbial safety aspects

“…It was also described that the strain Pantoea eucalypti M91 is capable of producing pyoverdine-like and pyochelin-like siderophores under alkaline growth conditions (Campestre et al, 2016). More recently, in a phylogenetic and comparative genomic study, desferrioxamine-like, enterobactinlike, and aerobactin-like siderophore biosynthetic gene clusters were found in several Pantoea strains (Soutar and Stavrinides, 2018). Judging from these findings, Pantoea strains are potentially capable of producing multiple and different types of siderophores.…”

“…Usually, hydroxamates are more commonly found in neutral to acid environments while catecholates are more commonly found in neutral to alkaline environments (Saha et al, 2013). Several bacterial genera were described to produce siderophores, such as Azotobacter (Baars et al, 2016;McRose et al, 2017;Romero-Perdomo et al, 2017), Azospirillum (Banik et al, 2016), Bacillus (Kesaulya et al, 2018;Pourbabaee et al, 2018), Dickeya (Sandy and Butler, 2011), Klebsiella (Bailey et al, 2018;Zhang et al, 2017), Nocardia (Hoshino et al, 2011), Pantoea (Burbank et al, 2015;Soutar and Stavrinides, 2018), Paenibacillus (Liu et al, 2017), Pseudomonas (Baune et al, 2017;Deori et al, 2018;Pourbabaee et al, 2018), Serratia (Coulthurst, 2014) and Streptomyces (Gáll et al, 2016;Goudjal et al, 2016;Schütze et al, 2014).…”