Ibrahim M, Schlegel H G
Biotechnol Bioeng. 1980 Sep;22(9):1877-94. doi: 10.1002/bit.260220908.
The supply of heterotrophically growing suspensions of Alcaligenes eutrophus PHB-4 with oxygen formed by the continuous addition of H2O2 in the presence of bovine liver catalase was found to be restricted to well-defined conditions. The catalase-H2O2 system proved to be suitable during the growth at low cell densities equivalent to 2 g dry weight/liter. When under these conditions the oxygen concentration was held constant at 1.8 mg O2/liter, the cells grew for 6-8 hr at a rate almost identical to that observed with conventional aeration. However, aeration with H2O2 for longer durations (10-20 hr) and at higher cell densities (5-20 g dry weight/liter) led invariably to cell damage and retardation of growth. The impairment of growth observed during the oxygen supply by the catalase-H2O2 system was traced back to the formation of gradually increasing steady-state concentrations of H2O2 in the medium. Possible sites of cell damage by H2O2 such as membrane function, excretion and function of siderophores, and synthesis of cell polymers have been studied, and the cytotoxic mechanism of low concentrations of H2O2 was discussed.
在牛肝过氧化氢酶存在的情况下，通过连续添加过氧化氢来为嗜氧产碱杆菌PHB - 4的异养生长悬浮液供氧，发现其受到明确条件的限制。在相当于2克干重/升的低细胞密度生长过程中，过氧化氢酶 - 过氧化氢系统被证明是合适的。在这些条件下，当氧浓度保持在1.8毫克O₂/升时，细胞以几乎与传统曝气时观察到的速率相同的速度生长6 - 8小时。然而，用过氧化氢曝气更长时间（10 - 20小时）和更高细胞密度（5 - 20克干重/升）总是会导致细胞损伤和生长迟缓。在通过过氧化氢酶 - 过氧化氢系统供氧过程中观察到的生长受损可追溯到培养基中过氧化氢稳态浓度的逐渐增加。已经研究了过氧化氢可能导致细胞损伤的部位，如膜功能、铁载体的分泌和功能以及细胞聚合物的合成，并讨论了低浓度过氧化氢的细胞毒性机制。
