sphingomonas gei sphingomonas gei sphingomonas gei is a gram-negative, strictly aerobic and motile bacteria from the genus of sphingomonas with a single polar flagellum which has been isolated from roots of the plant geum aleppicum from the mount taibai in the shaanxi province in china. sphingomonas gei scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: sphingomonadales family: sphingomonadaceae genus: sphingomonas binomial name sphingomonas geizhu et al. 2015 type strain cctcc ab 2013306, kctc 32449, zfgt-11