the cells of "vulcanisaeta" are straight to slightly curved rods, which range from 0.4 to 0.6 µm in width. in some cases, the cells are branched or bear spherical bodies at the terminals. the archaeon utilizes maltose, starch, malate, yeast extract, peptone, beef extract, casamino acids and gelatin as carbon sources, cannot utilize d-arabinose, d-fructose, lactose, sucrose, d-xylose, acetate, butyrate, formate, fumarate, propionate, pyruvate, succinate, methanol, fomamide, methylamine or trimethylamine. as electron acceptors, the organism uses sulfur and thiosulfate. unlike some other genetically similar archaea such as "thermocladium" or "caldivirga", "vulcanisaeta" grows in the absence of vitamin mixture or archaeal cell-extract solution in the medium.