Fungal degradation lignin

Quinone/Hydroquinone Formation. In studies on biodegradation of lignin models with ligninolytic cultures of P. chrysosporium (and other fungi), a number of quinones and hydroquinones were isolated. In other studies their formation has been implied from the isolation of their structural counterparts (29,30), where rapid fungal degradation of the quinones prevented their isolation. Various routes to these metabolic intermediates exist, which have been extensively reviewed (26,27). 

Because the three-dimensional structures of the peroxidase, its reductant cytochrome c, and the complex of the two (Fig. 16-9) are known, cytochrome c peroxidase is the subject of much experimental study. Other fungal peroxidases, some of which contain manganese rather than iron, act to degrade lignin (Chapter 25).218 A lignin peroxidase from the white wood-rot fungus Phanerochaete chrysosporium has a surface tryptophan with a specifically hydroxylated C(3 carbon atom which may have a functional role in catalysis.2183 0... 

Srebotnik E, Jensen Jr. KA, Hammel KE (1994) Fungal Degradation of Recalcitrant Nonphenolic Lignin Structures without Lignin Peroxidase. Proc Natl Acad Sci USA 91 ... 

Hammel, K. E. 1997. Fungal degradation of lignin. In Driven by Nature Plant Litter Quality and Decomposition (G. Cadisch, and K. E. Giller, Eds.), pp. 33—46. CAB International, Wallingford. 

The first report on the peroxidase transformation of dioxins was published by Hammel et al. in 1986 [116]. They transformed dibenzo[p]dioxin and 2-chlorodi-benzo / dioxin with lignin peroxidase from P. chrysosporium. Later on, with the aim to elucidate the pathway for the fungal degradation of 2.7-dichlorodi ben7.0-p-dioxin. the oxidation products generated by lignin peroxidase and manganese peroxidase... 

Riittimann-Johnson C, Lamar RT (1996) Polymerization of pentachlorophenol and ferulic acid by fungal extracellular lignin-degrading enzymes. Appl Environ Microbiol 62 3890-3893... 

Further metabolism of low molecular weight products of the initial degradation of lignin, however it occurs, is probably via classical modes. Vanillic acid, a prominent product of the fungal degradation of lignin (127), is degraded by substrate-inducible enzymes in P. chrysosporium (128, 129). 

JA Buswell, E Odier. Lignin biodegradation. CRC CritRev Biotechnol 6 1-60, 1987. TK Kirk, HHJ Yang, P Keyser. The chemistry and physiology of the fungal degradation of lignin. Dev Ind Microbiol 19 51-61, 1978. 

Iledge.s, J. I., Blanchette, R. A., Weliky, K., and Devol, A. II. (1988). Effects of fungal degradation on the CuO oxidation products of lignin A controlled laboratory study. Geodiim. C.osmodiim. Acta 52, 2717-2726. 

The pulp samples before and after the fungal degradation were air-dried and milled with Wiley Mill to flour (30 mesh). Lignin in pulp was isolated with the acidic dioxane extraction method described previously. Lignin extracted from die milled pulp before fungal degradation was used as a control. 

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