Analysis of alkali-lignin in a paper mill effluent decolourised with two Streptomyces strains by gas chromatography–mass spectrometry after cupric oxide degradation

Alkali-lignin samples obtained from an untreated paper mill effluent and from the effluent decolourised by the strains Streptomyces avermitilis CECT 3339 and Streptomyces scabies UAH 51 were analysed by gas chromatography–mass spectrometry (GC–MS) after cupric oxide degradation. The analysis of the depolymerisation products of the alkali-lignin from the decolourised effluents showed a strain specific modification of the aromatic moiety of the alkali-lignin. Moreover, both strains were able to breakdown the aryl–alkyl ether linkages between the cinnamic acids and the lignin. Finally, GC–MS analysis showed that both strains oxidised the alkali-lignin regardless of its initial degree of oxidation.