Fungal degradation of kraft lignin and lignin sulfonates prepared form synthetic 14C-lignins

• DOI: 10.1007/bf00413095
• Publication Date: 2004-11-09T03:47:58Z
• Authors: Knut Lundquist; T. Kent Kirk; William J. Connors
• Keywords: Phanerochaete; Chrysosporium; Degradation; Gel permeation chromatography; Chemical decomposition

Kraft lignins (KL), bleached kraft lignins (BKL), and lignin sulfonates (LS) were prepared from synthetic 14C-lignins labeled in the aromatic nuclei or in the propyl side chains. These and control lignins (CL) were incubated with the lignin-decomposing white-rot fungus, Phanerochaete chrysosporium Burds., in a defined culture medium containing cellulose as growth substrate. Decomposition was monitored by measuring the 14CO2 evolved. Average percentages of the [ring-14C]- and [side chain-14C]-lignins, respectively, recovered as 14CO2 at the cessation of 14CO2 evolution were: KL, 41 and 31; BKL, 42 and 26; LS, 28 and 21; and CL, 26 and 24. Gel permeation chromatography of radiolabeled materials extracted from spent cultures showed that substantial degradation to nonvolatile products had occurred. The polymeric components in the extracts were further degraded in fresh cultures. These results indicate that industrial lignins are significantly bioalterable, and that under favorable conditions industrial lignins are substantially biodegradable.