Utilization of H2O2 as the Oxygen Source by Bacteria of the Genera Pseudomonas and Rhodococcus

The growth of bacteria of the genera Pseudomonas and Rhodococcus in the presence of hydrogen peroxide as the sole source of oxygen was studied. The toxic effect of H₂O₂ in the concentration range of 100–200 g/ml was shown to extend the lag phase by two to three days. Apart from the peroxide toxicity, the bacterial growth was inhibited by the toxic effect of dissolved oxygen in concentrations over 100 g O₂/ml; in the presence of a liquid hydrocarbon phase, this effect was alleviated. Under decreased partial pressure of oxygen in the presence of hydrocarbons (12–15 vol %), culture growth was initiated at high initial concentrations of H₂O₂ (300 g/ml). When hydrogen peroxide concentrations exceeded 320 g/ml, no growth occurred, regardless of how much hydrocarbon was added.