acidisphaera acidisphaera acidisphaera is a genus in the phylum pseudomonadota (bacteria). the genus contains a single species, namely a. rubrifaciens with the following characteristics: strictly aerobic, light preferred mesophilic acidophilic (3.5–6.0 ph, optima of 4.5-5.0) bacteriochlorophyll (bchl a) and carotenoids production (salmon-pink colonies), the former contained zinc if grown in the presence of 1 mm zinc sulfate. chemo-organotrophic gram-negative, as expected from a proteobacterium isolated from acidic hot springs and mine drainage non-motile cocci / coccobacilli part of the major acidophilic alphaproteobacterial group with the genera acidiphilium and rhodopila acidisphaera scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: rhodospirillales family: acetobacteraceae genus: acidisphaera type species a. rubrifaciens etymology the name acidisphaera derives from:neo-latin noun acidum (from latin adjective acidus, sour), an acid; latin feminine gender noun sphaera, a ball, globe, sphere; neo-latin feminine gender noun acidisphaera, acid (-requiring) coccoid microorganism. while the specific epithet rubrifaciens comes from the latin adjective ruber -bra -brum, red; latin v. facio, to make; neo-latin participle adjective rubrifaciens, red-producing.)