2000 Fiscal Year Final Research Report Summary
Studies on the Relationship between Changes in Chemical Composition and Histochemical Morphology, and the Improvement in Digestibility of Rice Straw Treated with Sodium Hydroxide
| Project/Area Number |
11660266
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Zootechnical science/Grassland science
|
|---|
| Research Institution | IBARAKI UNIVERSITY |
|---|
Principal Investigator |
MINATO Hajime IBARAKI Univ., School of Agriculture, Professor, 農学部, 教授 (60282282)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MIYAGUCHI Yuji IBARAKI Univ., School of Agriculture, Assistant Professor, 農学部, 助手 (60250990)
TOYODA Atsushi IBARAKI Univ., School of Agriculture, Assistant Professor, 農学部, 助手 (00292483)
NAKAMURA Yutaka IBARAKI Univ., School of Agriculture, Associate Professor, 農学部, 助教授 (60007789)
|
|---|
| Project Period (FY) |
1999 – 2000
|
| Keywords | Rice Straw / In situ digestibility / Hemicellulose / Xylose / Phenolic acids / p-Coumaric acid / Ferulic acid / Lignin |
|---|
| Research Abstract |
Rice straw was evenly hand sprayed with an aqueous solution containing various amounts of NaOH to give 35% moisture content, and to provide 0 to 4% NaOH concentrations of rice straw dry matter (DM). Then the straw was stored in a vinyl bag for 1 to 21 days at room temperature. When the straw was treated with 4% NaOH for 21 days, the improvement of in situ digestibility of straw was maximum. In situ digestibilities of straw DM were negatively correlated with lignin and hemicellulose contents.
To characterize the features of cell wall lignins of untreated and 4% NaOH-treated rice straw, analyses of phenolics of the cell wall were done. The amounts of phenolics released from rice straw by the 4% NaOH treatment became abundant it the following order : vanillin, p-coumaric acid, ferulic acid and p-hydroxybenzaldehyde. And, about 50% of the esterified p-coumaric acid was released from rice straw by the 4% NaOH treatment.
In situ cellulose digesition of rice straw was significantly improved by the 4% NaOH treatment. In situ digestion of xylose residues in hemicellulose of the straw was inferior to that of other monosaccharides, but that of the straw was remarkably improved by the NaOH-treatment. The same amount of guaiacyl- and syringyl-lignins was released from the untreated rice straw during in situ digestion. On the other hand, more abundant syringyl-lignin than guaiacyl-lignin was released from NaOH-treated rice straw during the in situ digestion. Scanning electron microscopy showed that cell wall materials of rice straw were swollen by the NaOH-treatment and abundant fibrous materials were exposed.
These results suggest that a network structure built up from hemicellulosic polysaccharides and lignins, which embeds cellulose microfibrils, and phenolic acids linked to them inhibits in situ DM digestion of the rice straw.
|
Research Products
(8 results)
