Kim Minsung, Tanaka Yuri, Kajiura Hiroyuki, Misaki Ryo, Fujiyama Kazuhito
International Center for Biotechnology, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
FEMS Yeast Res. 2025 Jan 30;25. doi: 10.1093/femsyr/foaf002.
A complete iron deficiency in iron-sensitive oleaginous yeast showed insufficient biomass, resulting in a lower lipid amount, although lipid accumulation was greater compared to deficiency in other ions. In this study, the effect of functional iron deficiency on lipid production on Rhodotorula toruloides NBRC 0559 was examined. Two supplements, an iron-added (growth) supplement and an iron-free (lipid-producing) supplement were tested for detecting functional iron deficiency. The addition of iron-added supplement increased the biomass by 1.5-fold. Furthermore, the addition of iron-free supplement stimulated the growth of R. toruloides NBRC 0559 without loss of biomass (indeed, the biomass increased 1.2-fold) while also resulting in a deficiency of the iron needed for improved growth. Through iron-free supplement, the functional iron starvation effect resulted in improved lipid yield (1.7-fold) and an improved ratio of oleic acid (1.2-fold), which is considered an appropriate material for biodiesel, compared to the non-supplement-treated medium. Moreover, functional iron deficiency led to a 3.4-fold increase in the oleic acid rate compared to when all iron was completely removed from the medium. This study presents the effects and importance of iron in improving biomass and lipid production through the functional iron deficiency.
铁敏感型产油酵母完全缺铁时，生物量不足，导致脂质产量降低，不过与其他离子缺乏相比，脂质积累量更大。在本研究中，检测了功能性缺铁对红酵母NBRC 0559脂质生产的影响。测试了两种补充剂，一种添加铁的（用于生长的）补充剂和一种无铁的（用于产脂质的）补充剂，以检测功能性缺铁情况。添加添加铁的补充剂使生物量增加了1.5倍。此外，添加无铁补充剂刺激了红酵母NBRC 0559的生长，且生物量没有损失（实际上，生物量增加了1.2倍），同时还导致了促进生长所需铁的缺乏。通过无铁补充剂，功能性铁饥饿效应使脂质产量提高（1.7倍），油酸比例提高（1.2倍），与未补充处理的培养基相比，油酸被认为是生物柴油的合适原料。此外，与培养基中所有铁完全去除时相比，功能性缺铁使油酸比例提高了3.4倍。本研究展示了通过功能性缺铁，铁在提高生物量和脂质生产方面的作用及重要性。
