1988 Fiscal Year Final Research Report Summary
Roles of rumen ciliate protozoa on digestion of structural carbohydrate by ruminants
| Project/Area Number |
62560273
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
畜産学(含草地学)
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| Research Institution | Kyoto Prefectural University, Faculty of Agriculture |
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Principal Investigator |
USHIDA K. Kyoto Prefectural University, Faculty of Agriculture, 農学部, 助手 (50183017)
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| Co-Investigator(Kenkyū-buntansha) |
KOJIMA Y. Kyoto Prefectural University, Faculty of Agriculture, 農学部, 助教授 (80046490)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Cellulose digestion / Cellulolytic bacteria / Cellulolytic protozoa / Non-cellulolytic protozoa / Rumen |
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| Research Abstract |
Non-cellulolytic protozoa enhanced cellulolysis by mixed rumen populations to the similar wevels ehich were measured under the presence of cellulolytic protozoa. This enhancement was appeared to be due to indirect enhancement of cellulolytic bacteria by protozoa. When starch was present as an alternative substrate, cellulolysis was depressed without non-cellulolytic protozoa. This fact further suggested the significance of indirect enhancement of bacterial cellulolysis. As non-cellulolytic protozoa are predominant in the rumen, roles of protozoa were considered to be indirect. Following the experiment, similar experiments were conducted using mixed protozoal population including cellulolytic protozoa. In this time, starch depressed cellulolysis irrespective of presence of protozoa. following hypothesis was built in order to interpret those apparently incompatible results: Bacterial flora developed under the presence of non-cellulolytic protozoa differ from those under cellulolytic protozoa. Cellulolytic activity mainly depends on protozoa when cellulolytic protozoa present. Development of cellulolytic bacteria may not be supported, but rather restricted by protozoa in this case. Bacterial flora compositions were determined in order to verify the above hypothesis. Comparing with those in defaunated sheep rumen, sizes of amylolytic and cellulolytic bacteria were small when cellulolytic protozoa present. Xylanolytic and pectinolytic bacteria did not show notable defferences. These results apparently support above hypothesis and suggest the presence of antagonism between cellulolytic bacteria and protozoa. When cellulolytic protozoa are separated from cellulose digestion by the alternative substrate such as starch, cellulose digestion is depressed.
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