Hydrogen peroxide excretion by oral streptococci and effect of lactoperoxidase-thiocyanate-hydrogen peroxide.

摘要: Approved type strains of Streptococcus sanguis, S. mitis, mutans, and salivarius were grown under aerobic anaerobic conditions. The rate hydrogen peroxide excretion, oxygen uptake, acid production from glucose by washed-cell suspensions these studied, the levels enzymes in cell-free extracts which reduced oxygen, peroxide, or hypothiocyanite (OSCN-) presence NADH NADPH assayed. effects lactoperoxidase-thiocyanate-hydrogen on uptake intact cells, activity glycolytic extracts, intracellular intermediates also studied. All consumed glucose. anaerobically mutans excreted peroxide. There was higher oxidase peroxidase aerobically cells than cells. low all species. Acid production, and, consequently, excretion inhibited sanguis mitis had a capacity to recover this inhibition. Higher former an NADH-OSCN oxidoreductase, converted OSCN- into thiocyanate, explained difference. change after inhibition glycolysis actual indicated that primary target pathway glyceraldehyde 3-phosphate dehydrogenase.