 The rod-shaped and ellipsoid cells are 2-10 by 0.5-1 µm and 1-2 by 1 µm in size, respectively, and the spherical cells have a diameter of approximately 1 µm.The archaeon uses only a limited range of substrates, such as glucose, xylose, and fructose, for growth, and is unique in its inability to utilize yeast extract or peptone.Other substances that did not stimulate the organism's growth include organic acids, amino acids, alcohols, glycogen, and starch.