Characterization of hydrogen peroxide production by a novel oral streptococci,S. oligofermentans isolated from human oral cavity
一株口腔链球菌新种—寡发酵链球菌产过氧化氢特性的研究

High level of hydrogen peroxide was produced by S.oligofermentans,a novel oral streptococcus isolated from human oral cavity previously in our laboratory.To characterize the hydrogen peroxide production by S.oligofermentans,hydrogen peroxide yields at different growth phases and from different substrates were assayed.The results turned out that hydrogen peroxide production started at the beginning of logarithmic phase,and reached the maximal yield at the early stationary phase.Peptone and yeast extract could be the main substrates for hydrogen peroxide production.Moreover,lactate,as a fermentative product of glucose,can be another substrate for hydrogen peroxide production.Furthermore three oxidases activities possibly associated with H-2O-2 production were assayed,and both activities of lactate oxidase and NADH oxidase were detected under aerobic condition,while pyruvate oxidase activity was not detected in the permeabilized cells of S.oligofermentans,implying that S.oligofermentans could mainly rely on the two enzymes activities for H-2O-2 production.