DEGRADATION AND DECOLORIZATION OF SYNTHETIC DYES USING CRUDELAC CASE EXTRACTED FROM ASPERGILLUS FLAVUS GROWN ON DELONIX REGIA PODS

ABSTRACT Laccase is an oxidase enzyme found in fungi, bacteria and plants which has gained notable interest because of its potential for dye degradation. This study examines the use of crude laccase from Aspergillus flavus grown on delonix regia pods for the degradation of synthetic dyes.The laccase producing fungi were isolated from soil and decayed wood cultured on potato dextrose agar (PDA). Primary screening for laccase production was carried out on PDA-guaiacol agar plate and the hydrolysis zone were measured. The most potent laccase producer was used for laccase production using submerged state fermentation on delonix regia pods as substrate at pH (5.0) and temperature (35℃C).The identification of the fungi were carried out by morphological and microscopic methods.The decolorization potential of the crude laccase was carried out of congo red and malachite dye for a period of 120 hours in which the absorbance was taken at every 24hour interval. Out of the total twenty fung isolated five fungi were positive to the test for laccase production, W2b isolate was recorded as highest hydrolysis zone of 6.0mm. The isolate was identified as Aspergillus flavus while other laccase producing fungi were identifiedas Aspergillus flavus, Aspergillus fumigatus and Aspergillus nidulans. The result for the degradation showed a 96.54% and 80.02% reduction in malachite green and congo red, respectively after 120 hours. This study suggests that laccase from Aspergillus flavus is very effective for dye degradation, making it a good option for cleaning up industrial waste water and has the capacity of degrading and decolorizing industrial dves.