Figure 2. B. burgdorferi Are Sensitive to a Low Dose of H₂O₂ Produced by Glucose Oxidase (GOX).

(A) Pyruvate does not alter GOX activity in BSK-II medium. Ten units of GOX were added to BSK-II medium containing or lacking pyruvate. Glucose was measured for 6 h to determine GOX activity. Data shown are mean +/− SD (n = 2). (B) The presence of pyruvate reduces the presence of H₂O₂ in BSK-II medium. GOX (0.32 mU ml⁻¹) was added to BSK-II medium containing or lacking pyruvate and H₂O₂ was measured for 100 h. The linear rate of H₂O₂ production over 24 h is shown. Data are from 2 separate experiments performed in 2 separate batches of medium. (C) 5A4NP1 (left panel) and AH130 (right panel) were inoculated in BSK-II medium containing or lacking pyruvate in the presence or absence of GOX. Data shown are mean +/− SD from three separate experiments. The inset shows the specific growth rate (k, days⁻¹) during cultivation in GOX-containing BSK-II with (red bar) and without (blue) pyruvate. GOX was added at 0.32 mU ml⁻¹. A paired Student’s t test determined significance (* p≤0.05). (D) Experiments from (C) were repeated with strain 5A4NP1 using a physiologically relevant concentration of sodium pyruvate (100 µM) with GOX treatment. Data shown are from two separate experiments and the inset shows the specific growth rate (k, days⁻¹) during cultivation in GOX-containing BSK-II with (red bar) and without (blue) pyruvate. GOX was added at 0.32 mU ml⁻¹.