Biotreatment of tannin-rich beer-factory wastewater with white-rot basidiomycete Coriolopsis gallica monitored by pyrolysis/gas chromatography/mass spectrometry

Some fractions of beer-factory wastewaters represent an important environme ntal concern owing to their high content of polyphenols and dark-brown colo r. The capacity of Coriolopsis gallica to preferentially degrade lignin has been successfully applied in our laboratory to the biotreatment and decolo rization of paper-industry effluents, In this work, the ability of this whi te-rot fungus to degrade high-tannin-containing wastewaters is evaluated. U nder all the conditions studied, effluent decolorization and chemical oxyge n demand reduction achieved by C, gallica at day 12 of incubation were clos e to 50 and 65%, respectively. No adhesion of dark color to the fungal myce lium was observed suggesting that decolorization could be ascribed to C,gal lica degradation systems. Mycelium dry-weight values showed that C, gallica is tolerant to relatively high tannin content present in the effluent samp les. Ln the sample containing the highest effluent concentration (60% v/v), dry-weight values suggested an inhibition of fungal growth at day 6 of inc ubation and a further adaptation of the fungus to the stressing tannin effe ct at day 12 of fungal treatment. Pyrolysis/ gas chromatography/mass spectr ometry results showed a decrease of polyphenols pyrolysis products, mainly phenol and guaiacol, with the incubation time. All these results indicate t he potential use of C, gallica in bioremediation of tannin-containing indus trial wastewaters and in other applications where a reduction in polyphenol s content is required. Copyright (C) 2000 John Wiley & Sons, Ltd.