Ensifer (bacterium)

Ensifer
Sinorhizobium fredii strain USDA257 on an agar plate.
Scientific classification
Domain:	Bacteria
Phylum:	Proteobacteria
Class:	Alphaproteobacteria
Order:	Hyphomicrobiales
Family:	Rhizobiaceae
Genus:	Ensifer Casida, 1982
Type species
Ensifer adhaerens Casida, 1982
Species[1][2][3][4]
"Sinorhizobium abri" Ogasawara et al. 2003[5][6] Ensifer adhaerens Casida 1982[7] Ensifer alkalisoli Li et al. 2016 Ensifer americanus corrig. (Toledo et al. 2004) Wang et al. 2015[8] Ensifer arboris (Nick et al. 1999) Young 2003[9] "Ensifer aridi" Le Quéré et al. 2017[10][6] "Ensifer aridi" Rocha et al. 2020[11][6] "Sinorhizobium chiapanecum" Rincón-Rosales et al. 2009[12] "Ensifer collicola" Jang et al. 2017[6] Ensifer fredii (Scholla and Elkan 1984) Young 2003[13] Ensifer garamanticus Merabet et al. 2010[14] Ensifer glycinis Yan et al. 2016[15] "Sinorhizobium indiaense" Ogasawara et all. 2003[5][6] Ensifer kostiensis (Nick et al. 1999) Young 2003[9] Ensifer kummerowiae (Wei et al. 2002) Young 2003[16] Ensifer medicae (Rome et al. 1996) Young 2003[17] Ensifer meliloti (Dangeard 1926) Young 2003[18] Ensifer mexicanus Lloret et al. 2007[19] Ensifer morelensis corrig. (Wang et al. 2002) Wang et al. 2015 Ensifer numidicus Merabet et al. 2010[14] Ensifer psoraleae Wang et al. 2013[20] Ensifer saheli (De Lajudie et al. 1994) Young 2003[18] symbiovar acaciae symbiovar sesbaniae Ensifer sesbaniae Wang et al. 2015[20] Ensifer shofinae Chen et al. 2017 Ensifer sojae Li et al. 2011[21] Ensifer terangae (De Lajudie et al. 1994) Young 2003[18] symbiovar acaciae symbiovar sesbaniae
Synonyms[2]
Sinorhizobium Chen et al. 1988

Ensifer (often referred to in literature by its synonym Sinorhizobium) is a genus of nitrogen-fixing bacteria (rhizobia), three of which (Ensifer meliloti,^[22][23] Ensifer medicae^[24] and Ensifer fredii^[25][26]) have been sequenced.

Etymology

Ensifer is from the New Latin term ensifer, which means "sword-bearing" or "sword-bearer".^[7] The synonym Sinorhizobium is a combination of Medieval Latin sino (which means "China"), Greek rhizo (which means "root"), and New Latin bios (which means "life"). Thus, the generic name means "a bacterium living in a root in China".^[1][13]

Proper name

The name Ensifer was published in 1982 and the name Sinorhizobium was published in 1988. By the rules of the Bacteriological Code (1990 Revision) of the International Committee on Systematics of Prokaryotes (ICSP), the older name (Ensifer) has priority.^[27] In response to a request that the single extant species of Ensifer (Ensifer adhaerens) be moved to Sinorhizobium, a special ICSP subcommittee was formed to evaluate the request. It was ultimately ruled that Ensifer retained priority and that all Sinorhizobium species be transferred to the genus Ensifer.^[28][29] However, both terms continue to be used in published scientific literature, with Sinorhizobium being the more common.^[30]

Deprecated species

Two species have been described which have since been reclassified into existing species: Sinorhizobium morelense (now Ensifer adhaerens)^[27][31] and Sinorhizobium xinjiangense (now Ensifer fredii^[32][33]—though some dissent exists^[20][34]).

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN).^[1][2] The following phylogeny is based on whole-genome analysis.^[35]

This phylogeny is based on a constrained analysis of the 16S ribosomal RNA.^[35]

References