THE SYNTHESIS OF LIGNIN-LIKE COMPLEXES BY FUNGI

Abstract

In studies of the synthesis of lignin-like complexes from sucrose by filamentous fungi it was found that, in general, the black or brown fungi were comparatively high in these constituents whereas the colorless or light-colored organisms contained lower percentages. The average contents of lignin-like materials for the genera studied were for Cladosporium 21.1, Helminthosporium 19, Humicola 8.1, Dematum 7.1, Alternaria 6.8, Aspergillus 6.4, Metarrhizium 3.6, and Glio-cladium 2.4. These values represent the non-nitrogenous portion of the fungal substance that resisted digestion with 72% H2SO4. The differences between genera largely explain the lack of agreement among previous workers as to the ability of fungi to form substances that are resistant to decay. About 40-50% of the C of sucrose was converted into cell material by Cladosporium, Helminthosporium and Gliocladium; the corresponding values for the other organisms were 25 to 30%. Since the high-lignin organisms grow mostly on decaying vegetation at or above the soil surface, a farming system, such as that used in stubble mulch farming, should be favorable to a high yield of humus.