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Molecular Analysis of Archaea, Bacteria and Eucarya Communities in the Rumen - Review-
White, B.A.,Cann, I.K.O.,Kocherginskaya, S.A.,Aminov, R.I.,Thill, L.A.,Mackie, R.I.,Onodera, R. Asian Australasian Association of Animal Productio 1999 Animal Bioscience Vol.12 No.1
If rumen bacteria can be manipulated to utilize nutrients (i.e., ammonia and plant cell wall carbohydrates) more completely and efficiently, the need for protein supplementation can be reduced or eliminated and the digestion of fiber in forage or agricultural residue-based diets could be enhanced. However, these approaches require a complete and accurate description of the rumen community, as well as methods for the rapid and accurate detection of microbial density, diversity, phylogeny, and gene expression. Molecular ecology techniques based on small subunit (SSU) rRNA sequences, nucleic acid probes and the polymerase chain reaction (PCR) can potentially provide a complete description of the microbial ecology of the rumen of ruminant animals. The development of these molecular tools will result in greater insights into community structure and activity of gut microbial ecosystems in relation to functional interactions between different bacteria, spatial and temporal relationships between different microorganisms and between microorganisms and reed panicles. Molecular approaches based on SSU rRNA serve to evaluate the presence of specific sequences in the community and provide a link between knowledge obtained from pure cultures and the microbial populations they represent in the rumen. The successful development and application of these methods promises to provide opportunities to link distribution and identity of gastrointestinal microbes in their natural environment with their genetic potential and in situ activities. The use of approaches for assessing pupulation dynamics as well as for assessing community functionality will result in an increased understanding and a complete description of the gastrointestinal communities of production animals fed under different dietary regimes, and lead to new strategies for improving animal growth.
Application of Molecular Biology to Rumen Microbes -Review-
Kobayashi, Y.,Onodera, R. Asian Australasian Association of Animal Productio 1999 Animal Bioscience Vol.12 No.1
Molecular biological techniques that recently developed, have made it possible to realize some of new attempts in the research field of rumen microbiology. Those are 1) cloning of genes from rumen microorganisms mainly in E. coli, 2) transformation of rumen bacteria and 3) ecological analysis with nonculturing methods. Most of the cloned genes are for polysaccharidase enzymes such as endoglucanase, xylanase, amylase, chitinase and others, and the cloning rendered gene structural analyses by sequencing and also characterization of the translated products through easier purification. Electrotransformation of Butyrivibrio fibrisolvens and Prevotella ruminicola have been made toward the direction for obtaining more fibrolytic, acid-tolerant, depoisoning or essential amino acids-producing rumen bacterium. These primarily required stable and efficient gene transfer systems. Some vectors, constructed from native plasmids of rumen bacteria, are now available for successful gene introduction and expression in those rumen bacterial species. Probing and PCR-based methodologies have also been developed for detecting specific bacterial species and even strains. These are much due to accumulation of rRNA gene sequences of rumen microbes in databases. Although optimized analytical conditions are essential to reliable and reproducible estimation of the targeted microbes, the methods permit long term storage of frozen samples, providing us ease in analytical work as compared with a traditional method based on culturing. Moreover, the methods seem to be promissing for obtaining taxonomic and evolutionary information on all the rumen microbes, whether they are culturable or not.
METAL DEFICIENCY IN CLUSTER STAR-FORMING GALAXIES AT<i>Z</i>= 2
Valentino, F.,Daddi, E.,Strazzullo, V.,Gobat, R.,Onodera, M.,Bournaud, F.,Juneau, S.,Renzini, A.,Arimoto, N.,Carollo, M.,Zanella, A. IOP Publishing 2015 The Astrophysical journal Vol.801 No.2
<P>We investigate the environmental effect on the metal enrichment of star-forming galaxies (SFGs) in the farthest spectroscopically confirmed and X-ray-detected cluster, CL J1449+0856 at z = 1.99. We combined Hubble Space Telescope/WFC3 G141 slitless spectroscopic data, our thirteen-band photometry, and a recent Subaru/Multi-object InfraRed Camera and Spectrograph (MOIRCS) near-infrared spectroscopic follow-up to constrain the physical properties of SFGs in CL J1449+0856 and in a mass-matched field sample. After a conservative removal of active galactic nuclei, stacking individual MOIRCS spectra of 6 (31) sources in the cluster (field) in the mass range 10 <= log(M/M-circle dot) <= 11, we find a similar to 4 sigma. lower [N II]/H alpha ratio in the cluster than in the field. Stacking a subsample of 16 field galaxies with H beta and [O III] in the observed range, we measure an [O III]/H beta ratio fully compatible with the cluster value. Converting these ratios into metallicities, we find that the cluster SFGs are up to 0.25 dex poorer in metals than their field counterparts, depending on the adopted calibration. The low metallicity in cluster sources is confirmed using alternative indicators. Furthermore, we observe a significantly higher H alpha luminosity and equivalent width in the average cluster spectrum than in the field. This is likely due to the enhanced specific star formation rate; even if lower dust reddening and/or an uncertain environmental dependence on. the continuum-to-nebular emission differential reddening may play a role. Our findings might be explained by the accretion of pristine gas around galaxies at z = 2 and from cluster-scale reservoirs, possibly connected with a phase of rapid halo mass assembly at z > 2 and of a high galaxy merging rate.</P>
Sargent, M. T.,Daddi, E.,Bournaud, F.,Onodera, M.,Feruglio, C.,Martig, M.,Gobat, R.,Dannerbauer, H.,Schinnerer, E. IOP Publishing 2015 ASTROPHYSICAL JOURNAL LETTERS - Vol.806 No.1
<P>Gas and dust in star-forming galaxies at the peak epoch of galaxy assembly are presently the topic of intense study, but little is known about the interstellar medium (ISM) of distant, passively evolving galaxies. We report on a deep 3 mm band search with the IRAM/Plateau de Bure Interferometer for molecular (H-2) gas in a massive (M-star similar to 6 x 10(11) M-circle dot) elliptical galaxy at z= 1.4277, the first observation of this kind ever attempted. We place a 3 sigma upper limit of 0.32 Jy kms(-1) on the flux of the CO-(J = 2 -> 1) line or L-CO' < 8.8 x 10(9) Kkms(-1) pc(2), assuming a disk-like CO-morphology and a circular velocity scaling with the stellar velocity dispersion as in local early-type galaxies (ETGs). This translates to an H-2 mass of < 3.9 x 10(10) (alpha(CO)/4.4) M-circle dot or a gas fraction of less than or similar to 6% assuming a Salpeter initial mass function and an ISM dominated by H-2, as observed in many local, high-mass ellipticals. This low value approaches that of local ETGs, suggesting that the low star formation activity in massive, high-z passive galaxies reflects a true dearth of gas and a lesser role for inhibitive mechanisms like morphological quenching.</P>
Asato, N.,Hirayama, T.,Higa, T.,Onodera, R.,Shinjo, A.,Oshiro, S. Asian Australasian Association of Animal Productio 2003 Animal Bioscience Vol.16 No.2
Acetone, which is produced from butyric acid when it passes through the rumen wall, was infused into the rumen and jugular veins of three female goats to investigate the role of acetone in ruminating and masticating behavior. The ruminating behavior, as measured by the number of boli and the ruminating time, decreased (p<0.05) with intraruminal acetone infusion. However, the ruminating behavior did not change significantly in response to intravenous acetone infusion. Feed intake significantly decreased with intraruminal acetone infusion, but not with intravenous acetone infusion. The concentrations of acetone in the plasma increased significantly (p<0.05) with both acetone infusion regions. Ruminal fluid acetone, and isopropyl alcohol (IPA), which is one of the ketone bodies, produced from acetone by bacterial action in rumen, concentrations were significantly increased (p<0.05) with both acetone infusion regions. These results suggest that the chemoreceptors sensitive to acetone are more likely to be in the rumen epithelium, portal system, or liver, where they can respond to acetone levels.
Effects of Isopropyl Alcohol Infusions on the Ruminating Behavior of Goats
Asato, N.,Hirata, T.,Hirayama, T.,Onodera, R.,Shinjo, A.,Oshiro, S. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.8
Metabolites, such as isopropyl alcohol (IPA) produced by rumen fermentation, were intravenously infused into a jugular vein of goats during feeding to explore the mechanism and roles of IPA in ruminating behavior (number of boli and ruminating time). Three female goats were confined in metabolism cages with a stanchion, The ruminating behavior measured by the number of ruminations, ruminating time, number of remastications, and remasticating time decreased (p<0,05) with intravenous IPA infusion. The IPA concentrations and VFA concentrations increased in the blood circulation. Our data suggest that sensitive receptors of rumination to IPA are more likely to be in an area such as the brain stem where they can respond to blood metabolite levels.