bacillus horikoshii bacillus horikoshii bacillus horikoshii is a facultative anaerobe bacterium. it is a gram positive, alkaliphilic and alkalitolerant, aerobic endospore-forming bacteria. bacillus horikoshii scientific classification domain: bacteria phylum: bacillota class: bacilli order: bacillales family: bacillaceae genus: bacillus species: b. horikoshii binomial name bacillus horikoshiinielsen et al. 1995 this species has been recently transferred into the genus sutcliffiella. the correct nomenclature is sutcliffiella horikoshii.