gelria (bacterium) gelria (bacterium) gelria is a thermophilic, anaerobic, obligately syntrophic, glutamate-degrading, endospore-forming bacterial genus in the family thermoanaerobacteraceae. gelria scientific classification domain: bacteria phylum: bacillota class: clostridia order: thermoanaerobacterales family: thermoanaerobacteraceae genus: gelriaplugge et al. 2002 species gelria glutamica the name of the genus comes from gelre (present province of gelderland), one of the 12 provinces in the netherlands.