Lignin Impact on Fibre Degradation: 2—A Model Study Using Cellulosic Hydrogels
✍ Scribed by Sewalt, Vincent J H; Oliveira, Willer de; Glasser, Wolfgang G; Fontenot, Joseph P
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 477 KB
- Volume
- 71
- Category
- Article
- ISSN
- 0022-5142
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✦ Synopsis
The impact of lignin on cellulose degradation was studied in uitro using lignocellulosic hydrogels. Hardwood lignin (methoxyl content, 191 mg g-') was blended with cellulose in homogeneous phase solution (dimethylacetamide/LiCl solvent) in two concentrations (100 and 300 mg g-') and formed into lignocellulosic beads by dropwise addition of the lignocellulose solutions to an appropriate nonsolvent. The lignin was used before and after hydroxypropylation of the phenolic hydroxyl group. Cellulose degradation from these beads after 24 and 72 h incubation in buffered ruminal fluid was compared to that of control (cellulose) beads and to that of cellulose beads incubated in the presence of lignin. The rate of cellulose degradation from the hydrogels was low (12-16% degradation after 24 h). At 72 h, 21-50% of the cellulose was degraded. Cellulose degradation was enhanced (P < 0.01) by lignin blended into the beads, but depressed (P < 0.01) by lignin added to the incubation medium. The effect of lignin increased ( P < 0.001) with lignin concentration. Hydroxypropylation of lignin, which blocks the formation of quinone methide intermediates, enhanced (P < 0.001) the increase in cellulose degradation with lignin blending, and reduced ( P < 0.001) the inhibitory effect of lignin included in the incubation medium.