Department of Chemical Engineering, Faculty of Engineering, Catholic University of Chile, P.O. Box 6177, Santíago, Chile.
Appl Environ Microbiol. 1991 Jul;57(7):1980-6. doi: 10.1128/aem.57.7.1980-1986.1991.
Our results show that all of the brown rot fungi tested produce oxalic acid in liquid as well as in semisolid cultures. Gloeophyllum trabeum, which accumulates the lowest amount of oxalic acid during decay of pine holocellulose, showed the highest polysaccharide-depolymerizing activity. Semisolid cultures inoculated with this fungus rapidly converted C-labeled oxalic acid to CO(2) during cellulose depolymerization. The other brown rot fungi also oxidized C-labeled oxalic acid, although less rapidly. In contrast, semisolid cultures inoculated with the white rot fungus Coriolus versicolor did not significantly catabolize the acid and did not depolymerize the holocellulose during decay. Semisolid cultures of G. trabeum amended with desferrioxamine, a specific iron-chelating agent, were unable to lower the degree of polymerization of cellulose or to oxidize C-labeled oxalic acid to the extent or at the rate that control cultures did. These results suggest that both iron and oxalic acid are involved in cellulose depolymerization by brown rot fungi.
我们的结果表明，所有测试的褐腐真菌在液体和半固体培养中都能产生草酸。在分解松木全纤维素的过程中积累草酸量最低的密环菌表现出最高的多糖解聚活性。用这种真菌接种的半固体培养物在纤维素解聚过程中迅速将 C 标记的草酸转化为 CO(2)。其他褐腐真菌也能氧化 C 标记的草酸，尽管速度较慢。相比之下，用白腐菌彩绒革盖菌接种的半固体培养物不会显著分解酸，也不会在分解过程中使全纤维素解聚。用一种特定的铁螯合剂去铁胺处理的密环菌半固体培养物不能降低纤维素的聚合度，也不能像对照培养物那样将 C 标记的草酸氧化到相同程度或相同速度。这些结果表明，铁和草酸都参与了褐腐真菌对纤维素的解聚。
