Study of lignin biotransformation by Aspergillus fumigatus and white-rot fungi using /sup 14/C-labeled and unlabeled kraft lignins

Journal Article · Wed Jan 01 00:00:00 EST 1986 · Biotechnol. Bioeng.; (United States)

DOI:https://doi.org/10.1002/bit.260280313· OSTI ID:7119050

Kadam, K K; Drew, S W

The biodegradation of lignin by fungi was studied in shake flasks using /sup 14/C-labeled kraft lignin and in a deep-tank fermentor using unlabeled kraft lignin. Among the fungi screened, A. fumigatus - isolated in our laboratories - was most potent in lignin biotransformation. Dialysis-type fermentation, designed to study possible accumulation of low MW lignin-derived products, showed no such accumulation. Recalcitrant carbohydrates like microcrystalline cellulose supported higher lignolytic activity than easily metabolized carbohydrates like cellobiose. An assay developed to distinguish between CO/sub 2/ evolved from lignin and carbohydrate substrates demonstrated no stoichiometric correlation between the metabolism of the two cosubstrates. The submerged fermentations with unlabeled liqnin are difficult to monitor since chemical assays do not give accurate and true results. Lignolytic efficiencies that allowed monitoring of such fermentations were defined. Degraded lignins were clearly superior to C. versicolor in all aspects of lignin degradation; A fumigatus brought about substantial demethoxylation and dehydroxylation, whereas C. versicolor degraded lignins closely resembled undegraded kraft lignin. There was a good agreement among the different indices of lignin degradation, namely, /sup 14/CO evolution, OCH/sub 3/ loss, OH loss, and monomer and dimer yield after permanganate oxidation.

• Research Organization: Virginia Polytechnic Institute and State Univ., Blacksburg
• OSTI ID: 7119050
• Journal Information: Biotechnol. Bioeng.; (United States), Vol. 28:3
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
09 BIOMASS FUELS
FUNGI
PRODUCTIVITY
LIGNIN
BIODEGRADATION
CARBON 14 COMPOUNDS
CARBON DIOXIDE
COMPARATIVE EVALUATIONS
METABOLISM
TRACER TECHNIQUES
CARBOHYDRATES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLANTS
POLYSACCHARIDES
SACCHARIDES
550501* - Metabolism- Tracer Techniques
140504 - Solar Energy Conversion- Biomass Production & Conversion- (-1989)