Novel salt and alkali tolerant neotropical basidiomycetes for dye decolorisation in simulated textile effluent

Abstract

The initial alkaline pH and the concentration of sodium chloride in the synthetic liquid medium were a key factor in the capability of twenty-five white-rot fungi strains to decolorise the dye Reactive Blue 19. Six strains decolorised 90% of the dye at pH 8. 0, and only Peniophora cinerea decolorized 90% of the dye at pH 9. 0. Fourteen strains were capable of decolorising the dye in saline medium (sodium chloride 10 g l-1). P. ostreatus, P. cinerea and T. villosa were able to decolorize the dye both in medium with initial pH 8. 0 or in saline medium. These three strains were selected and evaluated for simulated alkali-saline textile effluent decolorisation in different conditions: time of cultivation for effluent addition (0, 5, 7 and 9 days), initial pH (4. 5 and 8. 0) and agitation (0 and 120 rpm). P. ostreatus and P. cinerea decolorised the alkali-saline textile effluent by 93. 0 and 25. 4%, when the medium's initial pH was 8. 0 or 4. 5, respectively, and the effluent was added in the 7th day of growth. T. villosa decolorized 40% when the effluent was added on the 9th day of cultivation at pH 4. 5. Agitation increased the effluent decolorisation by T. villosa, but inhibition was observed for P. cinerea and P. ostreatus. The results showed that each fungus presented a specific behavior in relation to the best culture conditions for decolorisation of alkali-saline effluent containing reactive dyes. The strains of P. ostreatus, P. cinerea and T. villosa were considered as promising alternative for the biodegradation of this effluent, employing the strategy of effluent addition after a certain period of fungal growth. © 2011 Springer Science+Business Media B.V.