Azospirillum lipoferum, is a gram negative a-proteobacteria extensively studied due to its properties to influence plant growth, due to this symbiotic characteristic this bacteria is qualified as a Growth-Promoting Rhizobacteria (PGPR). The organism was first described by Martinus Beijerinck who named it Spirillum lipoferum , in 1925. Later, the classification was revised by Tarrand et al. who renamed it Azospirillum lipoferum which means "small, fat bearing, spiral".
Species: Azospirillum lipoferum
Azospirillum lipoferum colonizes root plants forming a symbiotic Relationship where the plant benefits through N2 fixation, phytohormones, and hormone balance. The association with A. lipoferum promotes the elongation of plant roots. Constant genome rearrangements promotes population diversity leading as a escape mechanism to bypass host defenses.
Genome size of 6,846,400 bp
GC content: 67.7%
CDS of 6,094
Contains 1 chromosome and several plasmids (range: 40-550 kbp)
Many replicons with many being chromids (chromosome + plasmid)
Shares many genes with aquatic species which might be explained by evolutionary transition from marine to terrestrial environments.
Scientists suggests that the transition was possible due to horizontal gene transfer promoted by conjugation and transduction.