Table 1.

Major siderophore-producing PGPB for which the siderophore structure has been established.

Genus	Strain	Gram	Siderophore		Reference
			Name	Type
Azospirillum	Azospirillum brasilense	Negative	Spirilobactin	Catechol	[81]
	Azospirillum lipoferum	Negative	2,3-DHB, 3,5-DHB-threonine, 3,5-DHB-lysine	Catechol	[82]
Azotobacter	Azotobacter vinelandii	Negative	Aminochelin, Azotochelin, Protochelin, 2,3-DHB	Catechol	[68,104,105]
	Azotobacter vinelandii	Negative	Azotobactin	Mixed	[56,96]
		Negative	Vibrioferrin	Mixed	[21]
Bacillus	Bacillus megaterium	Positive	Schizokinen, N-schizokinen, N-schizokinen-A	Hydroxamate	[71,106]
	Bacillus subtilis, Bacillus thuringiensis	Positive	Itoic acid, Bacillobactin	Catechol	[85,107]
Pantoea	Pantoea vagans C9-1	Negative	Enterobactin-like	Catechol	[74]
		Negative	Desferrioxamine-like	Hydroxamate	[74]
	Pantoea eucalypti M91	Negative	Pyoverdine-like, Pyochelin-like	Mixed	[10]
Pseudomonas	Pseudomonas B10	Negative	Pseudobactin(s)	Mixed	[98]
	Pseudomonas fluorescens, Pseudomonas aeruginosa, Pseudomonas syringae, Pseudomonas aureofaciens	Negative	Pyoverdine(s)	Mixed	[94,95,108,109]
	Pseudomonas fluorescens	Negative	Ferribactin	Mixed	[93]
Rhizobium	Rhizobium radiobacter	Negative	Agrobactin	Catechol	[88,89]
	R. leguminosarum, R. phaseoli	Negative	Vicibactin	Hydroxamate	[78,79]
	Rhizobium leguminosarum	Negative	Schizokinen	Hydroxamate	[73]
		Negative	2,3-DHB-threonine	Catechol	[73]
	Rhizobium meliloti	Negative	Rhizobactin	Catechol	[77]