Decoloration of naphthol batik dye by biosurfactant-producing bacteria

Abstract

The potency of some local isolates, biosurfactant-producing bacteria on decolorization of naphtol was examined. Six isolates designated as AB01, AB02, NF02, NF09, HS06, and HS08 have been tested their abilities to degrade carbofuran. Before the isolated were tested their potencies to decolorize naphtol dye, their abilities to produce biosurfactant was performed. HS08 isolate showed the highest biosurfactant activity with Emulsion Index (EI) was 17. The isolates were grown on Bushnel Haas Agar (BHA) medium amended with 25 ppm of naphtol dye as the sole carbon source. Isolates which were grown on BHA medium with no addition of naphtol served as control. The result showed that all isolates grew much slowly on naphtol-containing agar medium compare to one that grew BHA. HS06 isolates showed the best growth with colony d was 12 mm, while that isolate could reach 30 mm when grew BHA with no naphtol. Based on the highest growth and EI, three isolates; AB01, NF09 and HS06 were chosen for their potencies on naphtol dye decolorization as mixed culture with different conditions which were shaking and static cultures. The result showed that shaking culture results in better decolorization compare to the static one. When applied as consortium, the isolates showed lower percentage of decolorization of dye (33%) compare to the ability as single culture (59%).