Biodegradation and Bioconversion of Coals by Fungi: Final Report

摘要

The project obtained in laboratory culture new varieties of fungi capable of bioconverting solid coals directly to liquid products, and characterized the rate and extent of bioconversion activity on a variety of coal types. Several hundred fungal isolates were screened for bioconversions of weathered lignite. At least 30 apparently unique strains displayed lignite biconversion activity. Each of the new lignite-solubilizing strains was assayed for comparative activity on three different weathered, Gulf Coast lignites. Different strains exhibited differing degrees of activity on the different lignites. Degeree of natural weathering appeared to be positively correlated with biosolubility of the three lignites. Taxonomic studies were made on selected fungal isolates; identifications to level of genus were made where possible. Cultures of some of the selected strains were sent to several research laboratories where the new strains have been applied to coal bioconversion research. Selected fungal strains were tested for bioconversions of other coals. Some of the highly weathered, higher-ranked coals were solubilized; others, even though weathered, were resistant to bioconversion. A quantitative assay technique was developed and, applied to selected fungi acting on several coals. Time-course measurements revealed marked differences in pattern, rate, and degree of solubilization of different coals by different organisms.