Isolation and Dye Decolorization of a Bacillus subtilis Strain LS02 Exhibiting Laccase Activity

A newly isolated strain LS02 was estimated for its ability in dye decolorization. The LS02 strain was identified as Bacillus subtilis by the combination of physicochemical tests and 16S rDNA sequence analysis. The isolated strain could oxidize the laccase substrate syringaldazine, indicating the existence of laccase activity. B. subtilis LS02 grown well in the pH range of 5.0~9.0, and showed an optimum growth temperature at 37ºC. Indigo carmine could be completely decolorized by B. subtilis LS02 after 4 days, whereas Remazol Brilliant Blue R, reactive black 5 and crystal violet were poorly decolorized. The result indicated that the laccase of B. subtilis LS02 may be suitable for the application in textile bleaching of indigo carmine.