Facultad de Ciencias Químicas, Universidad Autónoma de Coahuila, Unidad Saltillo, 25280, Saltillo, Coahuila, Mexico.
CONAHCYT, Universidad Autónoma de Coahuila, Unidad Saltillo, 25280, Saltillo, Coahuila, Mexico.
Bioprocess Biosyst Eng. 2024 Nov;47(11):1777-1787. doi: 10.1007/s00449-024-03068-3. Epub 2024 Aug 2.
The present study aims to analyze the interaction between Rhodotorula toruloides and magnetic nanoparticles and evaluate their effect on carotenoid production. The manganese ferrite nanoparticles were synthesized without chitosan (MnFeO) and chitosan coating (MnFeO-CS) by the co-precipitation method assisted by hydrothermal treatment. XRD (X-ray diffraction), Magnetometry, Dynamic Light Scattering (DLS) and FTIR (Fourier-Transform Infrared Spectroscopy), are used to characterize the magnetic nanoparticles. The crystallite size of MnFeO was 16 nm for MnFeO and 20 nm for MnFeO-CS. The magnetic saturation of MnFeO-CS was lower (39.6 ± 0.6 emu/g) than the same MnFeO nanoparticles (42.7 ± 0.3 emu/g), which was attributed to the chitosan fraction presence. The MnFeO-CS FTIR spectra revealed the presence of the characteristic chitosan bands. DLS demonstrated that the average hydrodynamic diameters were 344 nm for MnFeO and 167 nm for MnFeO-CS. A kinetic study of cell immobilization performed with their precipitation with a magnet demonstrated that interaction between magnetic nanoparticles and R. toruloides was characterized by an equilibrium time of 2 h. The adsorption isotherm models (Langmuir and Freundlich) were fitted to the experimental values. The trypan blue assay was used for cell viability assessment. The carotenoid production increased to 256.2 ± 6.1 µg/g dry mass at 2.0 mg/mL MnFeO-CS. The use of MnFeO-CS to stimulate carotenoid yeast production and the magnetic separation of biomass are promising nanobiotechnological alternatives. Magnetic cell immobilization is a perspective technique for obtaining cell metabolites.
本研究旨在分析粘红酵母与磁性纳米粒子的相互作用，并评估它们对类胡萝卜素生产的影响。采用共沉淀法，在水热条件下辅助合成了未经壳聚糖修饰的四氧化三锰纳米粒子（MnFeO）和壳聚糖修饰的四氧化三锰纳米粒子（MnFeO-CS）。采用 X 射线衍射（XRD）、磁强计、动态光散射（DLS）和傅里叶变换红外光谱（FTIR）对磁性纳米粒子进行了表征。MnFeO 的晶粒度为 16nm，MnFeO-CS 的晶粒度为 20nm。MnFeO-CS 的饱和磁化强度较低（39.6±0.6 emu/g），低于相同的 MnFeO 纳米粒子（42.7±0.3 emu/g），这归因于壳聚糖的存在。MnFeO-CS 的 FTIR 光谱显示了壳聚糖特征带的存在。DLS 表明，MnFeO 的平均水动力学直径为 344nm，MnFeO-CS 的平均水动力学直径为 167nm。用磁铁沉淀进行细胞固定化的动力学研究表明，磁性纳米粒子与粘红酵母的相互作用特征是平衡时间为 2h。吸附等温线模型（朗缪尔和弗伦德利希）拟合了实验值。台盼蓝法用于评估细胞活力。当 MnFeO-CS 浓度为 2.0mg/mL 时，类胡萝卜素产量增加到 256.2±6.1μg/g 干重。MnFeO-CS 用于刺激酵母生产类胡萝卜素和生物量的磁性分离是很有前途的纳米生物技术替代方案。磁性细胞固定化是获得细胞代谢物的有前途的技术。
