使用磁稳定流化床从水溶液中分离酵母细胞。

Al-Qodah Z, Al-Shannag M

Department of Chemical Engineering, Al-Balqa Applied University, Amman, Jordan.

Lett Appl Microbiol. 2006 Dec;43(6):652-8. doi: 10.1111/j.1472-765X.2006.02004.x.

AIMS

To separate Saccharomyces cerevisiae cells from aqueous solutions using magnetically stabilized fluidized beds (MSFB) that utilize a horizontal magnetic field, and to study the effect of some parameters, such as bed porosity and height, liquid flow rate and inlet concentration on cell removal efficiency and breakthrough curves.

METHODS AND RESULTS

The separation process was conducted in an MSFB under the effect of horizontal magnetic field. The magnetic particles used consist of a ferromagnetic core of magnetite (Fe3O4) covered by a stable layer of activated carbon to adsorb the yeast cells from the suspension. The yeast cell concentration in the effluent was determined periodically by measuring the absorbance at 610 nm. The effect of the magnetic field intensity on the bed porosity and consequently the exit-normalized cell concentration from the bed was studied. It was found that bed porosity increased by 75%, and the normalized cell concentration in the bed effluent decreased by 30%, when the magnetic field intensity was increased from 0 to 110 mT. In addition, increasing the magnetic field intensity and bed height delayed the breakthrough point, and allowed efficient cell removal. These results demonstrate an improved method to separate cells of low concentration from cell suspension.

CONCLUSIONS

This study allows the continuous separation of yeast cells from aqueous solutions in an MSFB. The removal efficiency is affected by different parameters including the bed height, flow rate and initial concentration. The removal efficiency reaches 82%, and could be improved by varying the operational parameters.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results obtained in this investigation show that the MSFB using horizontal fields represents a potential tool for the continuous separation of cell suspension from aqueous solution. This study will contribute to a better understanding of the hydrodynamic parameters on the separation efficiencies of the cell.

目的

使用利用水平磁场的磁稳定流化床（MSFB）从水溶液中分离酿酒酵母细胞，并研究一些参数，如床层孔隙率和高度、液体流速和入口浓度对细胞去除效率和穿透曲线的影响。

方法与结果

分离过程在水平磁场作用下的磁稳定流化床中进行。所使用的磁性颗粒由磁铁矿（Fe3O4）的铁磁核心组成，表面覆盖有一层稳定的活性炭层，用于从悬浮液中吸附酵母细胞。通过测量610nm处的吸光度定期测定流出物中的酵母细胞浓度。研究了磁场强度对床层孔隙率以及由此对床层出口归一化细胞浓度的影响。结果发现，当磁场强度从0增加到110mT时，床层孔隙率增加了75%，床层流出物中的归一化细胞浓度降低了30%。此外，增加磁场强度和床层高度延迟了突破点，并实现了高效的细胞去除。这些结果证明了一种从细胞悬浮液中分离低浓度细胞的改进方法。