Two-Dimensional Vibrational Spectroscopy III: Interpretation of the Degradation of Plant Cell Walls by White Rot Fungi

The degradation of lignocellulose by white rot fungi has been studied by two-dimensional vibrational spectroscopy to examine the particular functional groups on specific carbohydrates affected by the organisms. The organisms: P. chrysosporium K-3 (Pc), cellulase-less mutant 3113 from P. chrysosporium K-3, cellulase-less mutant 85118-b from P. chrysosporium K-3, Phellinus pini RAB-83-19 (Pp) and C. subvermispora FP 90031-sp (Cs) (and both P. pini and C. subvermispora), differed in the extent to which they removed the phenolic moiety from the carbohydrates and differed in the way that they utilised them. The Cs appears preferentially to utilise the C-5 carbohydrates while the Pc and Pp are much less specific, as evidenced by the changes in the 800–1200 cm⁻¹ C–O–C region of the mid-infrared spectrum. The cellulase-less mutants do not appear to be as active as the Pc and Pp and provide a gradient by which the other organisms' activity can be assessed. The fungal biomass seems to obscure the interpretation at the longer wavelengths, but the 2000 cm⁻¹ region is highly correlated to both carbohydrate and lignin wavelengths in the near infrared spectrum. The 2D technique permits a look at the degradation process and a way to see quickly the differing effects of the fungi on plant cell walls.