Decolourisation of amaranth azo dye by bacterial consortium immobilized ontozeolite nax and surfactant modified zeolite nax

Abstract

Three bacterial strains Citrohacter freundii strain A1, Enterococcus casseliflavus strain Cl, and Enterobacter cloacae strain L17 in consortium onto zeolite NaX were studied for their ability to decolourise the azo dye, Amaranth. Zeolite NaX, an inorganic nanoporous material as well as surfactant modified zeolite NaX (SMZ) were used as the solid support matrix for bacterial immobilization. All optimised parameters for instance inoculum size, dye, temperature and amount of zeolite previously determ ined were applied using the both types o f bacteria immobilized nanoporous support. Complete decolourisation of Amaranth was achieved anaerobically within 20 minutes by inoculating 10% (v/v) bacterial consortium of Al, Cl. and L17 at a 1:1:1 ratio with SMZ NaX, while 30 minutes for decolourisation of Amaranth by zeolite NaX. This was achieved in a 1/4 strength P5 medium ( pH7) containing 5 g/L of nutrient broth supplement, 2.5 g/L of glucose, incubated at 45°C under anaerobic condition. Presence of bacterial consortium immobilized onto inorganic nanoporous material was determined via Scanning Electron Microscopy (SEM). SEM micrographs confirm that the adsorption of the bacteria on the surface of the SMZ was better than zeolite NaX thus enhances decolourisation process.