thermoanaerobacter italicus thermoanaerobacter italicus thermoanaerobacter italicus is a species of thermophilic, anaerobic, spore-forming bacteria. thermoanaerobacter italicus scientific classification domain: bacteria phylum: bacillota class: clostridia order: thermoanaerobacterales family: thermoanaerobacteraceae genus: thermoanaerobacter species: t. italicus binomial name thermoanaerobacter italicuskozianowski et al. 1998 t. italicus was first isolated from hot springs in the north of italy. the growth range for the organism is 45 to 78°c, with optimal growth conditions at 70°c and ph 7.0. the organism stains gram-negative, although it has a gram-positive cell structure. the species was named italicus in reference to the italian hot springs in which it was first isolated. the organism was originally isolated because of its ability to digest pectin and pectate.