Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, National Center of Technology Innovation for Synthetic Biology, No. 32, Xiqi Road, Tianjin Airport Economic Park, 300308 Tianjin, China.
Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, National Center of Technology Innovation for Synthetic Biology, No. 32, Xiqi Road, Tianjin Airport Economic Park, 300308 Tianjin, China.
Int J Biol Macromol. 2024 Aug;275(Pt 2):133714. doi: 10.1016/j.ijbiomac.2024.133714. Epub 2024 Jul 6.
The synthesis mechanisms and function evaluation of selenium(Se)-enriched microorganism remain relatively unexplored. This study unveils that total Se content within A. oryzae A02 mycelium soared to an impressive 8462 mg/kg DCW, surpassing Se-enriched yeast by 2-3 times. Selenium exists in two predominant forms within A. oryzae A02: selenoproteins (SeMet 32.1 %, SeCys 14.4 %) and selenium nanoparticles (SeNPs; 53.5 %). The extensive quantitative characterization of the elemental composition, surface morphology, and size of SeNPs on A. oryzae A02 mycelium significantly differs from those reported for other microorganisms. Comparative RNA-Seq analysis revealed the upregulation of functional genes implicated in selenium transformation, activating multiple potential pathways for selenium reduction. The assimilatory and dissimilatory reductions of Se oxyanions engaged numerous parallel and interconnected pathways, manifesting a harmonious equilibrium in overall Se biotransformation in A. oryzae A02. Furthermore, selenium-enriched A. oryzae A02 was observed to primarily upregulate peroxisome activity while downregulating estrogen 2-hydroxylase activity in mice hepatocytes, suggesting its potential in fortifying antioxidant physiological functions and upholding metabolic balance.
富硒微生物的合成机制和功能评价仍相对未知。本研究揭示,米曲霉 A02 菌丝体中的总硒含量激增至令人瞩目的 8462mg/kg DCW,是富硒酵母的 2-3 倍。硒在米曲霉 A02 中有两种主要存在形式:硒蛋白(硒代蛋氨酸 32.1%,硒半胱氨酸 14.4%)和硒纳米颗粒(SeNPs;53.5%)。对米曲霉 A02 菌丝体上硒纳米颗粒的元素组成、表面形态和尺寸进行了广泛的定量表征,与其他微生物报道的结果有很大不同。比较 RNA-Seq 分析揭示了与硒转化相关的功能基因的上调,激活了多个硒还原的潜在途径。硒含氧阴离子的同化和异化还原涉及许多平行和相互关联的途径,在米曲霉 A02 的整体硒生物转化中表现出和谐的平衡。此外,富硒米曲霉 A02 被观察到主要上调过氧化物酶体活性,同时下调小鼠肝细胞中雌激素 2-羟化酶活性,表明其在增强抗氧化生理功能和维持代谢平衡方面具有潜力。