| 초록 |
High temperatures (30–36°C) inhibited astaxanthin accumulation in H. pluvialis under photoautotrophic conditions. The depression of carotenogenesis was primarily attributed to excess intracellular less reactive oxygen species (LROS; O2− and H2O2) levels generated under high temperature conditions. Here we show that the heat stress-driven inefficient astaxanthin production was improved by accelerating the iron-catalyzed Haber–Weiss reaction to convert LROS into more reactive oxygen species (MROS; O2 and OH•), thereby facilitating lipid peroxidation. As a result, during 18 days of photoautotrophic induction, the astaxanthin concentration of cells cultured in high temperatures in the presence of iron (450 μM) was dramatically increased by 75% (30°C) and 133% (36°C) compared to that of cells exposed to heat stress alone. The heat stress-driven Haber–Weiss reaction will be useful for economically producing astaxanthin by reducing energy cost and enhancing photoautotrophic astaxanthin production, particularly outdoors utilizing natural solar radiation including heat and light for photo-induction of H. pluvialis. |
