## 3 Results  
### Use of Wheat Bran as a Medium Component for BY4741 Cell Growth  
To evaluate whether the wheat bran could be used as a substitute for YNB, _S. cerevisiae_ was cultured in WG+HLMU medium (Figure 1a). As the result, the growth profiles in the media of WG+HLMU medium and YG+HLMU medium showed 0.80 \(\pm\) 0.07 and 0.96 \(\pm\) 0.04 of the OD\({}_{600}\) values as the cell density at 24 h, respectively, indicating that the cell density in WG+HLMU medium was lower than that in YG+HLMU medium. Additionally, the \(\mu_{\text{max}}\) values in the media of WG+HLMU medium and YG+HLMU medium were 0.277 \(\pm\) 0.002 in 6.0-9.0 h and 0.407 \(\pm\) 0.035 in 10.0-11.5 h as the logarithmic growth phases (Table 2), also indicating that the growth rate in WG+HLMU medium was lower than that in YG+HLMU medium, with a significant difference (\(p<0.01\)). On the other hand, the values of OD\({}_{600}\) and \(\mu_{\text{max}}\) as the growth profiles in the medium without the wheat bran and YNB did not show an increase in cell growth. In addition, to evaluate whether the wheat bran could be used as a carbon source instead of glucose, _S. cerevisiae_ was also cultivated in media excluding glucose (Figure 1b). A few increases of cell density in W+HLMU medium were found, compared to no increase in Y+HLMU medium at 24 h. In addition, no significant difference was experimentally confirmed in the correlation diagrams between the OD\({}_{600}\) value and cell production (g\(\cdot\)L\({}^{-1}\)) and between OD\({}_{600}\) value and viable cell density (cfu\(\cdot\)mL\({}^{-1}\)) obtained under all medium conditions, with the result that there was no difference in the weight per cell regardless of culture media. _S. cerevisiae_ could replace many nutrients of YNB for cell growth with the wheat bran, so the composition of the wheat bran was evaluated by comparing it to that of YNB (Table 3). The results showed that the wheat bran and YNB contained no lipids; the wheat bran contained 6.1 g\(\cdot\)L\({}^{-1}\) of total protein; the wheat bran also contained 15.1 g\(\cdot\)L\({}^{-1}\) of total carbohydrate (glucose: 1.7 g\(\cdot\)L\({}^{-1}\)) as the carbon source, unlike YNB. In addition, according to the results of the elemental analysis, essential components for cell growth such as Na, Fe, Ca, Cu, and Zn [32; 33; 34; 35; 36] appeared at levels below the detection limit for each mineral, as implied by 'not detected (N.D.)' given by Japan food research laboratories in the wheat bran, and the others in the wheat bran were lower than those in YNB, except for Mn.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Strain**} & \multirow{2}{*}{**Medium Name**} & \multirow{2}{*}{**Time Range (h)**} & \multicolumn{3}{c}{**Maximum Specific**} & \multirow{2}{*}{**Doubling**} & \multirow{2}{*}{**Cite**} \\  & & & & & & & **Growth Rate (\(\mu_{\text{max}}\) h\({}^{-1}\))** & & \\ \hline \multirow{9}{*}{BY4741} & WG+HLMU medium & 6.0 & \(\sim\) & 9.0 & 0.277 & \(\pm\) & 0.002 & 2.50 \(\pm\) & 0.01 \\  & YG+HLMU medium & 10.0 & \(\sim\) & 11.5 & 0.407 & \(\pm\) & 0.035 & 1.71 \(\pm\) & 0.15 \\  & G+HLMU medium & & & & & & N.D. & & N.D. \\ \cline{1-1}  & W+HLMU medium & 3.0 & \(\sim\) & 9.0 & 0.131 & \(\pm\) & 0.004 & 5.29 \(\pm\) & 0.15 \\  & Y+HLMU medium & & \(-\) & & & N.D. & & N.D. \\  & HLMU medium & & \(-\) & & & N.D. & & N.D. \\ \hline \multirow{9}{*}{BY4741} & WG+HMU medium & & \(-\) & & & N.D. & & N.D. \\  & WG+HLMU medium & 14.0 & \(\sim\) & 22.0 & 0.0536 & \(\pm\) & 0.0019 & 12.9 \(\pm\) & 0.5 \\  & WG+HLU medium & 4.0 & \(\sim\) & 22.0 & 0.0521 & \(\pm\) & 0.0007 & 13.3 \(\pm\) & 0.2 \\  & WG+HLM medium & 10.0 & \(\sim\) & 22.0 & 0.0484 & \(\pm\) & 0.0022 & 14.6 \(\pm\) & 0.7 \\ \cline{1-1}  & W+HMU medium & 6.0 & \(\sim\) & 16.0 & 0.0901 & \(\pm\) & 0.0048 & 7.71 \(\pm\) & 0.39 \\ \cline{1-1}  & W+HMU medium & & & & N.D. & & N.D. & & Figure 2b \\ \hline \hline \end{tabular}
\end{table}
Table 2: Growth properties of BY4741 in each medium.