Urea is hydrolyzed into ammonia and CO2 by bacterial ureases which are produced by some oral bacteria such as _________.

Urea is hydrolyzed into ammonia and CO2 by bacterial ureases which are produced by some oral bacteria such as _________.

• A. S. mutans
• B. P. gingivalis
• C. F. nucleatum
• D. S. salivarius

Answer: (D)

Urease activity in the oral microbiome is the ability of certain bacteria to hydrolyze urea into ammonia and carbon dioxide, which raises the local pH in the mouth. Streptococcus salivarius is a known urease-producing member of the oral flora, so it can perform ureolysis in saliva. The other bacteria listed are not typically recognized for urease production in the oral environment; Streptococcus mutans is mainly associated with acid production and demineralization, while Porphyromonas gingivalis and Fusobacterium nucleatum are anaerobic pathogens linked to periodontal disease rather than urease activity. Therefore, the bacterium among these that produces urease is Streptococcus salivarius.

Urease activity in the oral microbiome is the ability of certain bacteria to hydrolyze urea into ammonia and carbon dioxide, which raises the local pH in the mouth. Streptococcus salivarius is a known urease-producing member of the oral flora, so it can perform ureolysis in saliva. The other bacteria listed are not typically recognized for urease production in the oral environment; Streptococcus mutans is mainly associated with acid production and demineralization, while Porphyromonas gingivalis and Fusobacterium nucleatum are anaerobic pathogens linked to periodontal disease rather than urease activity. Therefore, the bacterium among these that produces urease is Streptococcus salivarius.