Jirakkakul Jiraporn, Cheevadhanarak Supapon, Punya Juntira, Chutrakul Chanikul, Senachak Jittisak, Buajarern Taridaporn, Tanticharoen Morakot, Amnuaykanjanasin Alongkorn
School of Bioresources and Technology, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10140, Thailand.
Bioresources Technology Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathumthani 12120, Thailand.
FEMS Microbiol Lett. 2015 Jan;362(2):1-8. doi: 10.1093/femsle/fnu032. Epub 2014 Dec 4.
Iron is an essential element for life. However, the iron overload can be toxic. Here, we investigated the significant increase of tenellin and iron-tenellin complex production in ferricrocin-deficient mutants of Beauveria bassiana. Our chemical analysis indicated that the ferricrocin-deficient mutants T1, T3 and T5 nearly abolished ferricrocin production. In turn, these mutants had significant accumulation of iron-tenellin complex in their mycelia at 247-289 mg g(-1) cell dry weight under iron-replete condition. Both tenellin and iron-tenellin complex were not detected in the wild-type under such condition. Mass analysis of the mutants' crude extracts demonstrated that tenellin formed a 3:1 complex with iron in the absence of ferricrocin. The unexpected link between ferricrocin and tenellin biosynthesis in ferricrocin-deficient mutants could be a survival strategy during iron-mediated oxidative stress.
铁是生命必需的元素。然而，铁过载可能具有毒性。在此，我们研究了球孢白僵菌铁载体缺乏突变体中tenellin和铁-tenellin复合物产量的显著增加。我们的化学分析表明，铁载体缺乏突变体T1、T3和T5几乎完全停止了铁载体的产生。相应地，在铁充足的条件下，这些突变体的菌丝体中铁-tenellin复合物大量积累，细胞干重为247 - 289 mg g(-1)。在这种条件下，野生型中未检测到tenellin和铁-tenellin复合物。对突变体粗提物的质谱分析表明，在没有铁载体的情况下，tenellin与铁形成了3:1的复合物。铁载体缺乏突变体中铁载体与tenellin生物合成之间意想不到的联系可能是铁介导的氧化应激期间的一种生存策略。
