Abstract
Correlation among color intensity, electron donating ability to $\alpha$, $\alpha$-diphenyl-$\beta$-dicrylhydrazy(DPPH) and cultivation conditions by Bacillus subtilis DC-2 were tested with response surface methodology. Both of pigment generation ability and DPPH were more affected by temperature than any other factor. The highest correlation was appeared between color intensity and DPPH as 0.8364 which is significant at 1% level. After fixing cultivation time which is not significant at 10% level to 84hrs as optical cultivation time, response surface methodology was conducted in regarding temperature and color intensity. As a result of overlapped contour map of color intensity and DPPH, when cultivation temperature was in the range of 38.9~41.1$^{\circ}C$ and pH was in the range of 8.34~9.12, optical density of color intensity was predicted higher than 0.374 at 390nm and DPPH was infered higher than 1.310 at 528nm. In the range of optical culture condition, cultivation temperature, pH and cultivation time was fixed to 4$0^{\circ}C$, 8.5 and 85hrs, respectively. In resulting, observation value of color intensity and DPPH was in the range of anticipation value as 0.386 at 390nm and 1.332 at 528nm respectively.