## 3 Results and Discussion
### EMR Results
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multicolumn{1}{c}{**Parameters**} & \multicolumn{1}{c}{**BB-1 in FSM**} & \multicolumn{1}{c}{**BB-1 in FSM**} & \multicolumn{1}{c}{**MSR-1 in**} & \multicolumn{1}{c}{**MSR-1 in**} & \multicolumn{1}{c}{**AMB-1 in**} & \multicolumn{1}{c}{**AMB-1 in**} \\  & & **New** & **Old** & **FSM New** & **FSM Old** & **MSGM New** & **MSGM Old** \\ \hline \multicolumn{1}{c}{Mixing angle, grad} & –66 (1) & –36 (4) & –82 (7) & –40 (2) & –41 (4) & –29 (5) \\ \hline \multirow{4}{*}{Gaussian 2} & \(g\)-factor & 3.388 (3) & 4.574 (3) & 2.354 (7) & 4.6 (1) & 4.54 (2) & 4.80 (9) \\ \cline{2-8}  & Line width \(\Gamma\), A/m & 11.58 (4) & 18.9 (1.1) & 64.8 (2.6) & 26.7 (1.4) & 19.0 (9) & 25.5 (2.8) \\ \cline{2-8}  & Amplitude, arb.un. & 77 (1) & 189 (33) & 470 (60) & 441 (30) & 320 (34) & 230 (35) \\ \hline \multirow{4}{*}{Gaussian 1} & \(g\)-factor & 2.348 (3) & 2.384 (1) & 2.183 (1) & 2.456 (7) & 2.294 (9) & 2.104 (2) \\ \cline{2-8}  & Line width \(\Gamma\), A/m & 23.24 (24) & 25.8 (5) & 16.2 (6) & 20.4 (4) & 22.3 (5) & 15.9 (1.6) \\ \cline{2-8}  & Amplitude, arb.un. & 134 (2) & 262 (6) & 55 (4) & 176 (10) & 197 (4) & 42 (19) \\ \hline \multirow{4}{*}{Gaussian 3} & \(g\)-factor & & & & 3.376 (4) & 3,04 (1) & 3.00 (4) \\ \cline{2-8}  & Line width \(\Gamma\), A/m & & & & 7.2 (6) & 6.2 (8) & 12.4 (1.8) \\ \cline{2-8}  & Amplitude, arb.un. & & & & 11 (2) & 11 (2) & 44 (16) \\ \hline \multirow{4}{*}{Gaussian 4} & \(g\)-factor & & & & & 2.49 (2) \\ \cline{2-8}  & Line width \(\Gamma\), A/m & & & & & 10.9 (1.1) \\ \cline{2-8}  & Amplitude, arb.un. & & & & & 34 (13) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Room temperature fit parameters of EMR spectra lines for _Magnetospirillum_ BB-1, MSR-1, and AMB-1 strains. providing an additional contribution to the anisotropy. As briefly discussed above, in the case of uniaxial anisotropy, one would expect the EMR signal from the _Magnetospirillum_ ensemble to split into two peaks. For the positive anisotropy constant, the second peak is shifted toward weaker fields [47], as it is really observed for the main (magenta and blue) peaks of the \"old\" and \"new\" samples in all the strains, with the exception of the MSR-1 \"new\" one (Figure 7e). In the latter case, both lines exhibit close \(g\)-factors, suggesting a rather small magnetic anisotropy. A comparison of the \(g\)-factors of the second main peak (see Table 2 and Figure 7, blue lines) for the \"new\" and \"old\" samples of BB-1, MSR-1, and AMB-1 strains shows their increase in the \"old\" samples for all the strains. In AMB-1, this increase is relatively small compared to the larger increase observed in BB-1 and the maximal increase in MSR-1 (Figure 7c,d and Table 2), suggesting the corresponding increase in magnetic anisotropy in these strains when stored after fixation with 5% formalin. Note the appearance of an additional weak peak in the EMR spectrum of the \"old\" sample of the MSR-1 strain, its position being between the main peaks (Figure 7c). In addition, note the appearance of the third weak peak in the spectrum of the \"new\" sample of the AMB-1 strain, accompanied by one more (the fourth peak) in the signal of the \"old\" sample of this strain; the positions of the additional peaks are between the main ones as well (Figure 7e,f and Table 2). This indicates different stability of the magnetosome chain in different strains and suggests the decrease of the magnetic anisotropy of the \"heavy\" fraction chain in parts of the bacterial ensembles. This can be caused by several factors: (i) the presence of cells at different stages of division with different lengths of magnetosome chains and different sizes of immature and mature magnetosomes; (ii) the shortening of the magnetosome chain, due to its partial degradation; and (iii) the folding of magnetosome chains when detached from the cytoskeleton of the cells, accompanied by decreasing both their magnetic moments and the contribution to magnetic anisotropy due to \"antiferromagnetic\" dipolar correlations.