Acid production by Actinomyces viscosus of root surface caries and non-caries origin during glycogen synthesis and degradation at different pH levels.
Actinomyces viscosus strains, freshly isolated from root surface caries lesions and intact root surfaces, were studied for their glycogen synthetic and degradative activities at pH 4.5, 5.0, and 7.0 in a pH-stat. At all three pH levels, root caries origin of A. viscosus synthesized up to three times as much glycogen compared to non-root caries origin. Since root caries origin of A. viscosus strains initially synthesized large amounts of glycogen, a longer period of time was required to deplete this polymer, resulting in an extended period of acid production, even at pH 4.5 and pH 5.0. This study suggests that the ability of A. viscosus of root caries origin to synthesize large quantities of glycogen and subsequently degrade this stored polymer slowly with acid production, at acidic pH levels, may play an important role in the root caries process.
Komiyama
K
K
Department of Oral Biology, University of Saskatchewan, Saskatoon, Canada.
Khandelwal
R L
RL
D000143:Acids / Q000378:metabolism; D016924:Actinomyces viscosus / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000032:analysis; D003773:Dental Plaque / Q000382:microbiology; D005947:Glucose / Q000378:metabolism; D006003:Glycogen / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D006019:Glycolysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017213:Root Caries / Q000382:microbiology*; D013997:Time Factors; D014092:Tooth Root / Q000382:microbiology*
D000143:Acids; D004269:DNA, Bacterial; D006003:Glycogen; D005947:Glucose