thermoanaerobacter mathranii thermoanaerobacter mathranii thermoanaerobacter mathranii is a thermophilic, anaerobic, spore-forming bacteria. thermoanaerobacter mathranii scientific classification domain: bacteria phylum: bacillota class: clostridia order: thermoanaerobacterales family: thermoanaerobacteraceae genus: thermoanaerobacter species: t. mathranii subspecies: thermoanaerobacter mathranii subsp. alimentarius thermoanaerobacter mathranii subsp. mathranii binomial name thermoanaerobacter mathraniilarsen et al. 1998 the bacteria was first isolated from an icelandic hot spring. the growth range for the organism is 50 to 75°c and ph 4.7-8.8, with optimal growth conditions at 70-75°c and ph 7.0. t. mathranii stains gram-variable, but is structurally gram-positive. the species was named by the researchers, "in honor of the late indra m. mathrani, who contributed greatly to our understanding of thermophilic anaerobes from hot springs during his short career." a subspecies, t. mathranii subsp. alimentarius was found in canned food.