Magnetic millifluidic fractionation of a heterogeneous cell culture for statistically relevant ananlysis of age-dependent population development

Magnetic nanoparticles are among the most diverse nanomaterials and gain increasing industrial interest since they can be processed with magnetic fields and separated from complex mixtures. The goal of this innovative project is to develop a millifluidic separation process which allows the fractionation of singular yeast populations. This allows to investigate the influence of exogenous stressors on the physiological properties of yeasts depending on their age. Yeast will be classified magnetically according to cell age with a millifluidic flow cell in order to give a reliable statement on the influence of cell age and heterogeneity of yeast cells on the production in the food industry.Cell division of yeast cells leads to a bud scar on the mother cell. Thus, the number of bud scars directly correlates with the cell generation. Bud scars contain significant amounts of chitin which is therefore an indicator for cell generation as well. To separate the cells according to their cell age, magnetic nanoparticles, which are functionalized reversibly via a His-tag system with a protein containing chitin binding domain (ChBD), are bound to the bud scars through the ChBD. This binding of MNP to the bud scars acts as a magnetic marker. Yeast cells are affected by magnetic fields while passing the flow cell and thus fractionated according to their magnetic properties. The arrangement of the magnetic field, the flow geometry and the flow rate facilitate a fractionation depending on the MNP content and agglomeration size.The fractionation of yeast cells according to their age will help to answer fundamental questions on the expression of stress relevant genes in singular cells and the influence of the cell age on the fermentation performance. Furthermore, the population dynamic in dependence of the physiological properties can be investigated. To answer these questions is of great scientific interest since it is very difficult to determine the age of yeast cells and this investigation will pave the way to a deeper understanding of heterogeneous and homogeneous cell systems.

磁性纳米颗粒是最多样化的纳米材料之一，并增加了工业兴趣，因为它们可以用磁场处理并与复杂的混合物分离。这个创新项目的目的是开发一个毫流体的分离过程，该过程允许单一酵母菌种群的分馏。这允许研究外源应激源对酵母菌生理特性的影响，具体取决于其年龄。酵母将根据细胞年龄进行磁性分类，并具有毫米流体流动细胞，以便对细胞年龄和酵母细胞对食品工业产量的影响的影响提供可靠的陈述。酵母菌细胞的细胞会导致母细胞上的芽疤痕。因此，芽疤痕的数量与细胞的产生直接相关。芽疤痕含有大量的几丁质，因此也是细胞产生的指标。为了根据细胞的年龄分离细胞，磁性纳米颗粒通过具有含有几丁质结合域（CHBD）的蛋白质的HIS标签系统可逆地化，通过CHBD结合到芽疤痕。 MNP与芽疤痕的这种结合充当磁标记。酵母细胞在通过流动池时受磁场的影响，因此根据其磁性特性进行分级。磁场的排列，流量和流速的排列有助于分馏，具体取决于MNP含量和团聚大小。根据其年龄，酵母细胞的分馏将有助于回答有关奇异细胞中压力相关基因表达的基本问题，以及细胞年龄对发酵性能的影响。此外，可以研究生理特性依赖性的种群动态。回答这些问题是非常有科学的兴趣，因为很难确定酵母细胞的年龄，这项研究将为对异质和均匀的细胞系统的更深入理解铺平道路。