''Azorhizobium'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

. They fix nitrogen in

symbiosis Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biological interaction, between two organisms of different species. The two organisms, termed symbionts, can fo ...

with plants in the genus '' Sesbania''. Strain ORS571 of ''A. caulinodans'' has been fully sequenced. ''Azorhizobium'' ''caulinodans'' ORS571 has exceptional properties because it is able to fix nitrogen in both aerobic free-living and symbiotic states ''Azorhizobium caulinodans'' ORS571 is a rice and wheat endophyte, and does not need plant metabolites to make functional nitrogenase, but low nitrogenase expression is observed when it is living in cereal roots.

References

Hyphomicrobiales Bacteria genera {{Hyphomicrobiales-stub