Thesis
Biodegradation of lignocellulosic biomass in soil: structural changes of lignin
Washington State University
Master of Science (MS), Washington State University
2010
Handle:
https://hdl.handle.net/2376/102449
Abstract
Soil is a natural reservoir for life that controls biogeochemical cycles apart from the potential for carbon sequestration through regenerative and degradative processes. The major degradative process in soil is considered to be plant cell wall degradation, which leads to critical structural changes and chemical modification/functionalization in lignin. Biological degradation process of the lignocellulosic biomass has been reported corresponding to the formation of soil organic matter (SOM) in soil, but the exact mechanism involved during the first step of bio degradation process of lignocellulosic biomass is not well understood. The biological degradation of wheat (Triticum aestivum L) straw/wood poplar (P. fastigiata L) chips blends in soil was studied by following the changes in the content and structure of cellulose, hemicellulose, and lignin during the incubation for sixteen weeks. Compositional and thermogravimetric analyses showed that modification/deconstruction of lignin and hemicellulose occurs prior to the release of cellulose. Fourier transform infrared spectroscopy (FTIR) analysis revealed changes occurring in the lignin structure from eighth week, along with cleavage of acetyl side chain of hemicellulose. Py-GC-MS and 13C and 1H NMR also show a reduction in the S/G ratio corresponding to the specificity of enzymatic effect on the -OCH3 group attached to the syringyl unit of lignin complex. This reaction started from the first week of biomass soil exposure. These results illustrate the importance of hemicellulose removal and specific lignin cleavage for enhanced cellulose microbial attack.
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Details
- Title
- Biodegradation of lignocellulosic biomass in soil
- Creators
- Mythreyi Chandoor
- Contributors
- Shulin Chen (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Systems Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525133601842
- Language
- English
- Resource Type
- Thesis