Degradation of chlorinated lignin compounds in a bleach plant effluent by the white-rot fungus Trametes versicolor

Abstract

Chlorinated lignin derivatives in a combined bleach plant effluent from sulphite pulping were degraded by several white-rot fungi among which Trametes versicolor (Coriolus versicolor) strains were the most efficient. With glucose as co-substrate, about 90% colour reduction was achieved within 3 days. Simultaneously, the concentration of chloro-organic compounds measured as adsorbable organic halogens decreased by about 45%. As shown by gel chromatography, the high-molecular-weight fraction in the effluent was completely depolymerized while over 50% of total aromatic compounds were degraded. The presence of a co-substrate was necessary for all these activities of the fungus. The residue obtained after degradation was extremely recalcitrant and not further degradable.