The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Felicity Crotty - One of the best experts on this subject based on the ideXlab platform.
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Protozoan pulses unveil their pivotal position within the soil food web
Microbial Ecology, 2012Co-Authors: Felicity Crotty, Rod P Blackshaw, P. J. MurrayAbstract:Protozoa are one of the most abundant groups of bacterivores within the soil and are responsible for mineralisation of bacterial biomass, having a large impact on C and N cycling. Little is known of their contribution to soil nutrient transfers or the identity of their consumers. Here, for the first time indigenous flagellates and ciliates, enriched to 83 atom% for 13C and 10 atom% for 15N, were introduced to soil cores from two different land managements, grassland and woodland with the same soil type, to trace the flow of Protozoan C and N through the soil food web. Nematodes, Collembola, earthworms and insect larvae obtained the greatest amounts of C and N of Protozoan origin, either through direct consumption or uptake of biomass post-cell death. Our results show that changes in management, affect the functioning of the soil food web and the utilisation of Protozoa as a food source.
Charles J. Newbold - One of the best experts on this subject based on the ideXlab platform.
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Influence of foliage from different accessions of the sub-tropical leguminous tree, Sesbania sesban, on ruminal Protozoa in Ethiopian and Scottish sheep
Animal Feed Science and Technology, 1999Co-Authors: Belete Teferedegne, P O Osuji, A A Odenyo, F Mcintosh, R. J. Wallace, Charles J. NewboldAbstract:Nine different accessions of Sesbania sesban were examined for their toxicity to ciliate Protozoa from sheep receiving a mixed grass hay-barley/fishmeal concentrate in Aberdeen, Scotland, Several accessions were much more toxic than those (ILRI 10865, ILRI 15036) identified and tested in a previous study. Two highly toxic accessions and one less toxic accession were compared with ILRI 15036 in a feeding trial in Debre Zeit, Ethiopia with sheep receiving a sululta hay-wheat bran diet. No suppression of Protozoal numbers occurred in response to S. sesban supplementation (200 g/day). When rumen fluid removed from sheep on the supplemented diet was tested in vitro, Protozoal activity appeared to be inhibited less by S. sesban in the mixed population than in either washed Protozoa from the same rumen fluid or than had occurred in Scottish sheep. It was concluded that dietary, microbial or animal factors in the Ethiopian sheep had caused the destruction of the antiProtozoal material present in even the most potent accessions of S. sesban. (C) 1999 Elsevier Science B.V. All rights reserved.Peer reviewe
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influence of foliage from different accessions of the sub tropical leguminous tree sesbania sesban on ruminal Protozoa in ethiopian and scottish sheep
Animal Feed Science and Technology, 1999Co-Authors: P O Osuji, A A Odenyo, Belete Teferedegne, F.m Mcintosh, R. J. Wallace, Charles J. NewboldAbstract:Abstract Nine different accessions of Sesbania sesban were examined for their toxicity to ciliate Protozoa from sheep receiving a mixed grass hay–barley/fishmeal concentrate in Aberdeen, Scotland. Several accessions were much more toxic than those (ILRI 10865, ILRI 15036) identified and tested in a previous study. Two highly toxic accessions and one less toxic accession were compared with ILRI 15036 in a feeding trial in Debre Zeit, Ethiopia with sheep receiving a sululta hay–wheat bran diet. No suppression of Protozoal numbers occurred in response to S. sesban supplementation (200 g/day). When rumen fluid removed from sheep on the supplemented diet was tested in vitro, Protozoal activity appeared to be inhibited less by S. sesban in the mixed population than in either washed Protozoa from the same rumen fluid or than had occurred in Scottish sheep. It was concluded that dietary, microbial or animal factors in the Ethiopian sheep had caused the destruction of the anti-Protozoal material present in even the most potent accessions of S. sesban .
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influence of foliage from african multipurpose trees on activity of rumen Protozoa and bacteria
British Journal of Nutrition, 1997Co-Authors: Charles J. Newbold, S El M Hassan, J Wang, M E Ortega, R. J. WallaceAbstract:Samples and extracts of foliage from African multipurpose trees were screened for their effects on rumen Protozoa and bacteria with a view to predicting their safety as feed supplements and for identifying species with potential antiProtozoal activity. The species tested were Acacia aneura, Chamaecytisus palmensis, Brachychiton populneum, Flindersia maculosa, Sesbania sesban, Leucaena leucocephala and Vernonia amyedalina. Antimicrobial effects were mild except for S. sesban, which was highly toxic to rumen Protozoa in vitro, and A. aneura, which was toxic to rumen bacteria. The antiProtozoal factor in S. sesban was apparently associated with the fraction of the plant containing saponins. When S. sesban was fed to sheep, Protozoal numbers fell by 60% after 4 d, but the population recovered after a further 10 d. In vitro experiments demonstrated that washed Protozoa from later times were no more resistant to S. sesban than on initial exposure, suggesting that other micro-organisms, probably the bacteria, adapted to detoxify the antiProtozoal agent. Thus S. sesban may be useful in suppressing Protozoa and thereby improving protein flow from the rumen, but only if the bacterial metabolism of the antiProtozoal factor can be avoided.
Belete Teferedegne - One of the best experts on this subject based on the ideXlab platform.
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Influence of foliage from different accessions of the sub-tropical leguminous tree, Sesbania sesban, on ruminal Protozoa in Ethiopian and Scottish sheep
Animal Feed Science and Technology, 1999Co-Authors: Belete Teferedegne, P O Osuji, A A Odenyo, F Mcintosh, R. J. Wallace, Charles J. NewboldAbstract:Nine different accessions of Sesbania sesban were examined for their toxicity to ciliate Protozoa from sheep receiving a mixed grass hay-barley/fishmeal concentrate in Aberdeen, Scotland, Several accessions were much more toxic than those (ILRI 10865, ILRI 15036) identified and tested in a previous study. Two highly toxic accessions and one less toxic accession were compared with ILRI 15036 in a feeding trial in Debre Zeit, Ethiopia with sheep receiving a sululta hay-wheat bran diet. No suppression of Protozoal numbers occurred in response to S. sesban supplementation (200 g/day). When rumen fluid removed from sheep on the supplemented diet was tested in vitro, Protozoal activity appeared to be inhibited less by S. sesban in the mixed population than in either washed Protozoa from the same rumen fluid or than had occurred in Scottish sheep. It was concluded that dietary, microbial or animal factors in the Ethiopian sheep had caused the destruction of the antiProtozoal material present in even the most potent accessions of S. sesban. (C) 1999 Elsevier Science B.V. All rights reserved.Peer reviewe
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influence of foliage from different accessions of the sub tropical leguminous tree sesbania sesban on ruminal Protozoa in ethiopian and scottish sheep
Animal Feed Science and Technology, 1999Co-Authors: P O Osuji, A A Odenyo, Belete Teferedegne, F.m Mcintosh, R. J. Wallace, Charles J. NewboldAbstract:Abstract Nine different accessions of Sesbania sesban were examined for their toxicity to ciliate Protozoa from sheep receiving a mixed grass hay–barley/fishmeal concentrate in Aberdeen, Scotland. Several accessions were much more toxic than those (ILRI 10865, ILRI 15036) identified and tested in a previous study. Two highly toxic accessions and one less toxic accession were compared with ILRI 15036 in a feeding trial in Debre Zeit, Ethiopia with sheep receiving a sululta hay–wheat bran diet. No suppression of Protozoal numbers occurred in response to S. sesban supplementation (200 g/day). When rumen fluid removed from sheep on the supplemented diet was tested in vitro, Protozoal activity appeared to be inhibited less by S. sesban in the mixed population than in either washed Protozoa from the same rumen fluid or than had occurred in Scottish sheep. It was concluded that dietary, microbial or animal factors in the Ethiopian sheep had caused the destruction of the anti-Protozoal material present in even the most potent accessions of S. sesban .
Michael Bonkowski - One of the best experts on this subject based on the ideXlab platform.
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Protozoa and plant growth the microbial loop in soil revisited
New Phytologist, 2004Co-Authors: Michael BonkowskiAbstract:All nutrients that plants absorb have to pass a region of intense interactions between roots, microorganisms and animals, termed the rhizosphere. Plants allocate a great portion of their photosynthetically fixed carbon to root-infecting symbionts, such as mycorrhizal fungi; another part is released as exudates fuelling mainly free-living rhizobacteria. Rhizobacteria are strongly top-down regulated by microfaunal grazers, particularly Protozoa. Consequently, beneficial effects of Protozoa on plant growth have been assigned to nutrients released from consumed bacterial biomass, that is, the 'microbial loop'. In recent years however, the recognition of bacterial communication networks, the common exchange of microbial signals with roots and the fact that these signals are used to enhance the efflux of carbon from roots have revolutionized our view of rhizosphere processes. Most importantly, effects of rhizobacteria on root architecture seem to be driven in large by Protozoan grazers. Protozoan effects on plant root systems stand in sharp contrast to effects of mycorrhizal fungi. Because the regulation of root architecture is a key determinant of nutrient- and water-use efficiency in plants, Protozoa provide a model system that may considerably advance our understanding of the mechanisms underlying plant growth and community composition.
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interactions between earthworms and soil Protozoa a trophic component in the soil food web
Soil Biology & Biochemistry, 1997Co-Authors: Michael Bonkowski, Matthias SchaeferAbstract:Abstract Earthworms and Protozoa are, in terms of biomass, the most important groups of soil fauna in beech forests on limestone in southern Lower Saxonia (Germany). To investigate the effect of high Protozoan numbers on earthworm distribution, a multiple choice feeding experiment was set up in fumigated soil, reinoculated with different numbers of naked amoebae, Protozoa commonly found in that soil. Distribution of Aporrectodea caliginosa (Savigny) after 1 wk was correlated with numbers of amoebae in soil. Other experiments confirmed digestion of Protozoa by earthworms. The weight gain of young A. caliginosa in soil with amoebae was twice that in soil without Protozoa. Direct observations of fresh cast material confirmed that active Protozoa were digested by A. caliginosa. Lower Protozoan numbers in faeces of Octolasion lacteum (Orley) than in the surrounding soil were found by dilution series, indicating grazing on the active part of soil Protozoa by earthworms. The experiments provide evidence that A. caliginosa is actively searching for places with high Protozoan densities and that Protozoa may play a significant role in earthworm nutrition.
R. J. Wallace - One of the best experts on this subject based on the ideXlab platform.
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Influence of foliage from different accessions of the sub-tropical leguminous tree, Sesbania sesban, on ruminal Protozoa in Ethiopian and Scottish sheep
Animal Feed Science and Technology, 1999Co-Authors: Belete Teferedegne, P O Osuji, A A Odenyo, F Mcintosh, R. J. Wallace, Charles J. NewboldAbstract:Nine different accessions of Sesbania sesban were examined for their toxicity to ciliate Protozoa from sheep receiving a mixed grass hay-barley/fishmeal concentrate in Aberdeen, Scotland, Several accessions were much more toxic than those (ILRI 10865, ILRI 15036) identified and tested in a previous study. Two highly toxic accessions and one less toxic accession were compared with ILRI 15036 in a feeding trial in Debre Zeit, Ethiopia with sheep receiving a sululta hay-wheat bran diet. No suppression of Protozoal numbers occurred in response to S. sesban supplementation (200 g/day). When rumen fluid removed from sheep on the supplemented diet was tested in vitro, Protozoal activity appeared to be inhibited less by S. sesban in the mixed population than in either washed Protozoa from the same rumen fluid or than had occurred in Scottish sheep. It was concluded that dietary, microbial or animal factors in the Ethiopian sheep had caused the destruction of the antiProtozoal material present in even the most potent accessions of S. sesban. (C) 1999 Elsevier Science B.V. All rights reserved.Peer reviewe
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influence of foliage from different accessions of the sub tropical leguminous tree sesbania sesban on ruminal Protozoa in ethiopian and scottish sheep
Animal Feed Science and Technology, 1999Co-Authors: P O Osuji, A A Odenyo, Belete Teferedegne, F.m Mcintosh, R. J. Wallace, Charles J. NewboldAbstract:Abstract Nine different accessions of Sesbania sesban were examined for their toxicity to ciliate Protozoa from sheep receiving a mixed grass hay–barley/fishmeal concentrate in Aberdeen, Scotland. Several accessions were much more toxic than those (ILRI 10865, ILRI 15036) identified and tested in a previous study. Two highly toxic accessions and one less toxic accession were compared with ILRI 15036 in a feeding trial in Debre Zeit, Ethiopia with sheep receiving a sululta hay–wheat bran diet. No suppression of Protozoal numbers occurred in response to S. sesban supplementation (200 g/day). When rumen fluid removed from sheep on the supplemented diet was tested in vitro, Protozoal activity appeared to be inhibited less by S. sesban in the mixed population than in either washed Protozoa from the same rumen fluid or than had occurred in Scottish sheep. It was concluded that dietary, microbial or animal factors in the Ethiopian sheep had caused the destruction of the anti-Protozoal material present in even the most potent accessions of S. sesban .
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influence of foliage from african multipurpose trees on activity of rumen Protozoa and bacteria
British Journal of Nutrition, 1997Co-Authors: Charles J. Newbold, S El M Hassan, J Wang, M E Ortega, R. J. WallaceAbstract:Samples and extracts of foliage from African multipurpose trees were screened for their effects on rumen Protozoa and bacteria with a view to predicting their safety as feed supplements and for identifying species with potential antiProtozoal activity. The species tested were Acacia aneura, Chamaecytisus palmensis, Brachychiton populneum, Flindersia maculosa, Sesbania sesban, Leucaena leucocephala and Vernonia amyedalina. Antimicrobial effects were mild except for S. sesban, which was highly toxic to rumen Protozoa in vitro, and A. aneura, which was toxic to rumen bacteria. The antiProtozoal factor in S. sesban was apparently associated with the fraction of the plant containing saponins. When S. sesban was fed to sheep, Protozoal numbers fell by 60% after 4 d, but the population recovered after a further 10 d. In vitro experiments demonstrated that washed Protozoa from later times were no more resistant to S. sesban than on initial exposure, suggesting that other micro-organisms, probably the bacteria, adapted to detoxify the antiProtozoal agent. Thus S. sesban may be useful in suppressing Protozoa and thereby improving protein flow from the rumen, but only if the bacterial metabolism of the antiProtozoal factor can be avoided.
