Ciliate protozoa

Dehority, Burk A.

doi:10.1007/1-4020-3791-0_6

Cited by 9 publications

(10 citation statements)

References 14 publications

(9 reference statements)

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“…Samples for protozoa counting were mixed with 9% formaldehyde and preserved at −4°C, then counted in a haemacytometer under light microscope (Nikon YS100, Nikon, Yokohama, Japan) using the method of Dehority (2005) . Group-specific primers for methanogens ( mcrA ), total bacteria and anaerobic fungi, and species-specific primers for R. flavefaciens and F. succinogenes are listed in Table 1 , as described by Denman and McSweeney (2006) and Denman et al (2007) .…”

Section: Methodsmentioning

confidence: 99%

Effect of Gynosaponin on Rumen <i>In vitro</i> Methanogenesis under Different Forage-Concentrate Ratios

Manatbay

Cheng

Mao

et al. 2014

Asian Australas. J. Anim. Sci

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The study aimed to investigate the effects of gynosaponin on in vitro methanogenesis under different forage-concentrate ratios (F:C ratios). Experiment was conducted with two kinds of F:C ratios (F:C = 7:3 and F:C = 3:7) and gynosaponin addition (0 mg and 16 mg) in a 2×2 double factorial design. In the presence of gynosaponin, methane production and acetate concentration were significantly decreased, whereas concentration of propionate tended to be increased resulting in a significant reduction (p<0.05) of acetate:propionate ratio (A:P ratio), in high-forage substrate. Gynosaponin treatment increased (p<0.05) the butyrate concentration in both F:C ratios. Denaturing gradient gel electrophoresis (DGGE) analysis showed there was no apparent shift in the composition of total bacteria, protozoa and methanogens after treated by gynosaponin under both F:C ratios. The real-time polymerase chain reaction (PCR) analysis indicated that variable F:C ratios significantly affected the abundances of Fibrobacter succinogenes, Rumninococcus flavefaciens, total fungi and counts of protozoa (p<0.05), but did not affect the mcrA gene copies of methanogens and abundance of total bacteria. Counts of protozoa and abundance of F.succinogenes were decreased significantly (p<0.05), whereas mcrA gene copies of methanogens were decreased slightly (p<0.10) in high-forage substrate after treated by gynosaponin. However, gynosaponin treatment under high-concentrate level did not affect the methanogenesis, fermentation characteristics and tested microbes. Accordingly, overall results suggested that gynosaponin supplementation reduced the in vitro methanogenesis and improved rumen fermentation under high-forage condition by changing the abundances of related rumen microbes.

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Section: Methodsmentioning

confidence: 99%

Effect of Gynosaponin on Rumen <i>In vitro</i> Methanogenesis under Different Forage-Concentrate Ratios

Manatbay

Cheng

Mao

et al. 2014

Asian Australas. J. Anim. Sci

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“…Rumen protozoa, exclusively ciliates, rank second only to bacteria in cellular biomass of the ruminal microbiota. They are only found in the rumen and similar habitats (Dehority, 1986 , 2005 ) where they play important roles in feed digestion and homeostasis of the rumen ecosystem (Firkins et al, 2007 ; Newbold et al, 2015 ). However, they are also blamed for promoting methane (CH 4 ) emission due to their mutualistic relationship with methanogens by producing hydrogen (Newbold et al, 1995 ).…”

Section: Introductionmentioning

confidence: 99%

Do Ruminal Ciliates Select Their Preys and Prokaryotic Symbionts?

Park

2018

Front. Microbiol.

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Ruminal ciliates both preys on and form symbiotic relationships with other members of the ruminal microbiota for their survival. However, it remains elusive if they have selectivity over their preys or symbionts. In the present study, we investigated the above selectivity by identifying and comparing the free-living prokaryotes (FLP) and the ciliate-associated prokaryotes (CAP) using Illumina MiSeq sequencing of 16S rRNA gene amplicons. We used single ciliates cells of both monocultures of Entodinium caudatum and Epidinium caudatum and eight different ciliate genera isolated from fresh rumen fluid of dairy cows. Irrespective of the source (laboratory monocultures vs. fresh isolates) of the single ciliate cells, the CAP significantly differed from the FLP in microbiota community profiles. Many bacterial taxa were either enriched or almost exclusively found in the CAP across most of the ciliate genera. A number of bacteria were also found for the first time as ruminal bacteria in the CAP. However, no clear difference was found in methanogens between the CAP and the FLP, which was confirmed using methanogen-specific qPCR. These results suggest that ruminal ciliates probably select their preys and symbionts, the latter of which has rarely been found among the free-living ruminal prokaryotes. The bacteria enriched or exclusively found in the CAP can be target bacteria to detect and localize using specific probes designed from their 16S rRNA sequences, to characterize using single-cell genomics, or to isolate using new media designed based on genomic information.

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“…Samples were taken at a variety of depths to reduce variability due to the visual observation of vessel stratification. Vessel protozoal cell counts were completed using the Sedgewick–Rafter chamber following the procedure of Dehority ().…”

Section: Methodsmentioning

confidence: 99%

“…Daily DM and protozoal samples were taken from each vessel using a 10‐mL graduated pipette. The tip of the pipette was removed to allow large digesta particles to freely flow into the pipette (Dehority, ). Samples were taken just prior to the 10:30 hours feeding, and 60 ml of sample was collected from the vessel.…”

Section: Methodsmentioning

confidence: 99%

Evaluation of a single‐flow continuous culture fermenter system for determination of ruminal fermentation and enteric methane production

Dillard

Roca-Fernández

Rubano

et al. 2019

Animal Physiology Nutrition

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A 4‐unit, single‐flow continuous culture fermenter system was developed to assess in vitro nutrient digestibility, volatile fatty acid (VFA) concentration and daily enteric methane (CH4) production of ruminant diets. The objective was to develop a closed‐vessel system that maintained protozoal populations and provided accurate predictions of total CH4 production. A diet of 50% orchardgrass (Dactylis glomerata L.) and 50% alfalfa (Medicago sativa L.) was fed during 4, 10‐day periods (7‐day adaptation and 3‐day collection). Fermenters were fed 82 g of dry matter (DM)/day in four equal feedings. pH and temperature were taken every 2 min, and CH4 concentration was measured every 10 min. Samples for DM and protozoal counts were taken daily, and daily effluent samples were collected for determination of DM, VFA and NH3‐N concentrations. There was no effect (p > 0.17) of adaptation versus collection days on vessel and effluent DM, temperature or pH. Initial protozoal counts decreased (p < 0.01), but recovered to initial counts by the collection period. Total VFA, acetate, propionate and isobutyrate concentrations did not differ (p ≥ 0.13) among periods or days of the collection period. There was no difference (p ≥ 0.37) among days or periods in total daily CH4 production and CH4 production per g of OM, NDF, digestible OM or digestible NDF fed. Data collected throughout 4 experimental periods demonstrated that the system was able to reach a steady state in fermentation well within the 7‐day adaptation period and even typically variable data (i.e., CH4 production) were stable within and across periods. While further research is needed to determine the relationship between this system and in vivo data, this continuous culture fermenter system provides a valid comparison of in vitro ruminal fermentation and enteric CH4 production of ruminant diets that can then be further validated with in vivo studies.

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Ciliate protozoa

Cited by 9 publications

References 14 publications

Effect of Gynosaponin on Rumen <i>In vitro</i> Methanogenesis under Different Forage-Concentrate Ratios

Effect of Gynosaponin on Rumen <i>In vitro</i> Methanogenesis under Different Forage-Concentrate Ratios

Do Ruminal Ciliates Select Their Preys and Prokaryotic Symbionts?

Evaluation of a single‐flow continuous culture fermenter system for determination of ruminal fermentation and enteric methane production

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Ciliate protozoa

Cited by 9 publications

References 14 publications

Effect of Gynosaponin on Rumen &lt;i&gt;In vitro&lt;/i&gt; Methanogenesis under Different Forage-Concentrate Ratios

Effect of Gynosaponin on Rumen &lt;i&gt;In vitro&lt;/i&gt; Methanogenesis under Different Forage-Concentrate Ratios

Do Ruminal Ciliates Select Their Preys and Prokaryotic Symbionts?

Evaluation of a single‐flow continuous culture fermenter system for determination of ruminal fermentation and enteric methane production

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Effect of Gynosaponin on Rumen <i>In vitro</i> Methanogenesis under Different Forage-Concentrate Ratios

Effect of Gynosaponin on Rumen <i>In vitro</i> Methanogenesis under Different Forage-Concentrate Ratios