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