Decolorization of Remazol Black-B using a thermotolerant yeast, Kluyveromyces marxianus IMB3

The ability of Kluyveromyces marxianus IMB3 to decolorize Remazol Black-B d ye was investigated. The effect of environmental conditions, such as pH and temperature were examined. No noticeable effects on decolorization were ob served when pH varied from 3.0-55. Maximum colour removal, 98%, was achieve d at 37 degreesC. Little or no colour removal was detected when K. marxianu s IMB3 was incubated under anaerobic conditions. Further investigation, in which decolorization was monitored under extreme temperatures and low pH (t o inhibit growth) and using ten fold dense inoculum, revealed that decolori zation was due to biosorption to the yeast cells and not due to a metabolic reaction. (C) 2000 Elsevier Science Ltd. All rights reserved.