The effect of a constant magnetic field on the metabolism and viability of magnetic biosorbents based on yeast cells

The damaging effect of magnetic labeling with magnetite nanoparticles and a permanent magnetic field on the viability, metabolism and magnetic properties of magnetically labeled yeast cells, which can be used as magnetically controlled biosorbents with passive and active biosorption mechanisms, has been studied. The magnetic properties of magnetically labeled cells were evaluated using the Faraday scale method. It has been shown that the magnetic susceptibility of magnetically labeled cells increases with an increase in the concentration of iron per 1 cell (C_Fe) and does not change for several days for cells cultured in and without permanent magnetic field. The damaging effect on the viability of the studied yeast cells was assessed by the difference in the relative proportion of living cells in the population at the beginning and end of their cultivation. The number of living cells was estimated by methylene blue staining and counting of stained cells in the Goryaev chamber. It is shown that the damaging effect of magnetic labeling in the studied C_Fe range does not depend on C_Fe when cultivated without permanent magnetic field and increases with increasing C_Fe when cultivated in permanent magnetic field. The metabolism of magnetically labeled cells was assessed by the release of protons from yeast cells during their glucose processing (acidification test). It has been shown that magnetic labeling reduces the intensity of proton release from the cell by no more than 30%. Thus, in this work it is shown that using magnetic labeling with magnetite nanoparticles, it is possible to obtain viable yeast cells with paramagnetic susceptibility. Such magnetically labeled cells can be used as magnetically controlled biosorbents that can carry out passive and active biosorption of toxicants and at the same time effectively separate using magnetic separators from the cleaned medium.