Some rumen ciliates have endosymbiotic methanogens

Finlay, Bland J.; Esteban, Genoveva F.; Clarke, Ken J.; Williams, Alan G.; Embley, T. Martin; Hirt, Robert P.

doi:10.1111/j.1574-6968.1994.tb06758.x

Cited by 299 publications

(132 citation statements)

References 20 publications

Supporting

Mentioning

125

Contrasting

Unclassified

Order By: Relevance

“…Krumholz et al (1983) found that the methanogenic activity in the rumen fluid was highest in fractions containing large numbers of protozoa. It is also reported that the capacity of competition by methanogens for hydrogen with fumarate-reducers was increased when associated with protozoa (Finlay et al, 1994). This is in line with good growth by methanogens and protozoa when living in symbiosis (Wolin, 1974), and with the fact that fumarate is more effective in reducing methane production in protozoa-depleted ruminal fluid (Asanuma et al, 1999b).…”

Section: Discussionmentioning

confidence: 60%

“…Protozoa serve not only as host for methanogens, but also produce hydrogen in large quantities in a specialized organelle (hydrogenosome; Morgavi et al, 2010). This hydrogen is metabolized by methanogens that are found inside (Finlay et al, 1994) or in close association with protozoal cells (Stumm et al, 1982). The interaction between methanogens and protozoa is a typical example of interspecies hydrogen transfer, which favors both of them (Hillman et al, 1988;Ushida and Jouany, 1996).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of disodium fumarate on ruminal fermentation and microbial communities in sheep fed on high-forage diets

Zhou

McSweeney

Wang

et al. 2012

Animal

View full text Add to dashboard Cite

This study was conducted to investigate effects of disodium fumarate (DF) on fermentation characteristics and microbial populations in the rumen of Hu sheep fed on high-forage diets. Two complementary feeding trials were conducted. In Trial 1, six Hu sheep fitted with ruminal cannulae were randomly allocated to a 2 3 2 cross-over design involving dietary treatments of either 0 or 20 g DF daily. Total DNA was extracted from the fluid-and solid-associated rumen microbes, respectively. Numbers of 16S rDNA gene copies associated with rumen methanogens and bacteria, and 18S rDNA gene copies associated with rumen protozoa and fungi were measured using real-time PCR, and expressed as proportion of total rumen bacteria 16S rDNA. Ruminal pH decreased in the DF group compared with the control (P , 0.05). Total volatile fatty acids increased (P , 0.001), but butyrate decreased (P , 0.01). Addition of DF inhibited the growth of methanogens, protozoa, fungi and Ruminococcus flavefaciens in fluid samples. Both Ruminococcus albus and Butyrivibrio fibrisolvens populations increased (P , 0.001) in particle-associated samples. Trial 2 was conducted to investigate the adaptive response of rumen microbes to DF. Three cannulated sheep were fed on basal diet for 2 weeks and continuously for 4 weeks with supplementation of DF at a level of 20 g/day. Ruminal samples were collected every week to analyze fermentation parameters and microbial populations. No effects of DF were observed on pH, acetate and butyrate (P . 0.05). Populations of methanogens and R. flavefaciens decreased in the fluid samples (P , 0.001), whereas addition of DF stimulated the population of solid-associated Fibrobacter succinogenes. Population of R. albus increased in the 2nd to 4th week in fluid-associated samples and was threefold higher in the 4th week than control week in solid samples. Analysis of denaturing gradient gel electrophoresis fingerprints revealed that there were significant changes in rumen microbiota after adding DF. Ten of 15 clone sequences from cut-out bands appearing in both the 2nd and the 4th week were 94% to 100% similar to Prevotella-like bacteria, and four sequences showed 95% to 98% similarity to Selenomonas dianae. Another 15 sequences were obtained from bands, which appeared in the 4th week only. Thirteen of these 15 sequences showed 95% to 99% similarity to Clostridium sp., and the other two showed 95% and 100% similarity to Ruminococcus sp. In summary, the microorganisms positively responding to DF addition were the cellulolytic bacteria, R. albus, F. succinogenes and B. fibrisolvens as well as proteolytic bacteria, B. fibrisolvens, P. ruminicola and Clostridium sp.

show abstract

Section: Discussionmentioning

confidence: 60%

Section: Discussionmentioning

confidence: 99%

Effects of disodium fumarate on ruminal fermentation and microbial communities in sheep fed on high-forage diets

Zhou

McSweeney

Wang

et al. 2012

Animal

View full text Add to dashboard Cite

show abstract

“…Methane is produced normally during fermentation of feeds in the rumen by methanogenic archaea. The removal of protozoa can decrease methane production, as some populations of methanogens remain associated with protozoa as ectosymbionts and endosymbionts (57,93,94) . Theasaponin caused an increase in propionate production, while methane and isobutyrate production were decreased (89) .…”

Section: Methane Productionmentioning

confidence: 99%

“…Nevertheless, some studies have demonstrated that saponins may decrease the activity of methane-producing genes or rate of methane production per methanogenic cell (51,57) . Many methanogens are found in both etco-and endosymbiotic associations with protozoa, which are responsible for up to 37 % of rumen methanogenesis (93) . It has been estimated that a single protozoan cell may contain 10 3 -10 4 methanogens before feeding, decreasing to one to ten methanogens after feeding (94) .…”

Section: Explaining the Effects Of Saponins In Modifying Digestion Anmentioning

confidence: 99%

The effect and mode of action of saponins on the microbial populations and fermentation in the rumen and ruminant production

2009

View full text Add to dashboard Cite

The growing public concerns over chemical residues in animal-derived foods and threats of antibiotic-resistant bacteria have renewed interest in exploring safer alternatives to chemical feed additives in ruminant livestock. Various bioactive phytochemicals including saponins appear to be potential 'natural' alternatives to 'chemical' additives in modulating rumen fermentation favourably and animal performance. Saponins are a diverse group of glycosides present in many families of plants. The primary effect of saponins in the rumen appears to be to inhibit the protozoa (defaunation), which might increase the efficiency of microbial protein synthesis and protein flow to the duodenum. Furthermore, saponins may decrease methane production via defaunation and/or directly by decreasing the activities (i.e. rate of methanogenesis or expression of methane-producing genes) and numbers of methanogens. Saponins may also selectively affect specific rumen bacteria and fungi, which may alter the rumen metabolism beneficially or adversely. The ammonia-adsorption and modulation of digesta passage in the rumen by saponins have also been implicated in altering rumen metabolism, but their physiological responses are likely to be negligible compared with microbiological effects. The effects of saponins on rumen fermentation have not been found to be consistent. These discrepancies appear to be related to the chemical structure and dosage of saponins, diet composition, microbial community and adaptation of microbiota to saponins. There is need for systematic research based on chemical structures of saponins, nutrient composition of diets and their effects on rumen microbial ecosystem to obtain consistent results. The present paper reviews and discusses the effects and mode of action of saponins on microbial community and fermentation in the rumen, and ruminant performance.

show abstract

“…In addition, saponins can improve rumen fermentation and nitrogen metabolism [27]. Furthermore, saponins may inhibit rumen methanogen populations through a reduction in protozoa numbers [28], because methanogens have both ecto-and endo-symbiotic relationships with protozoa [29]. Consequently, methanogen species associated with protozoa usually decrease with decreasing protozoa numbers [30].…”

Section: B In Vitro Rumen Fermentation Characteristicsmentioning

confidence: 99%

Effect of Mixed Microbial Culture on Fermentation of Beverage Residues and the Effect of the Fermented Beverage Residues on in Vitro Rumen Fermentation and Methane Production

Senevirathne¹,

Okamoto²,

Takahashi³

et al. 2012

IJBBB

View full text Add to dashboard Cite

Abstract-The aim of this study was to increase the nutritive value of coffee, green and oolong tea residues and assess if the fermented residues have the potential to mitigate enteric methane emissions. A mixed microbial culture (20 g/kg) was added to each residue and the mixture incubated for 3 d at 35°C (anaerobically) and 2 weeks at 30°C (aerobically). Unfermented and fermented beverage residues were assayed for their saccharide and ethanol content. Four separate total mixed rations (TMR) were prepared using the three fermented beverage residues and hay (control). The fermented residues (2 g dry matter (DM)) were individually mixed with hay (3 g DM) and concentrate (5 g DM) and the in vitro rumen methane output was quantified during the 24 h incubation period using the continuous gas quantification system. The fermented residues of coffee, oolong tea and green tea had higher concentrations of cellotriose, cellobiose and xylobiose than the corresponding unfermented residues. Ethanol concentration was higher in the fermented coffee and green tea residues than in their respective unfermented residues. The methane output (L CH4/24 h) from the TMR containing fermented residues of coffee (0.118 L), oolong tea (0.127 L) and hay (control; 0.123 L) did not differ, but the methane output was lower for all compared to the TMR containing fermented green tea residue (0.141 L). The results suggest that fermented coffee, oolong tea and green tea residues are a potentially good source of protein and energy, and fermented residues of coffee caused a numerical decrease methane output.Index Terms-Beverage residues, in vitro, methane, mixed microbial culture.

show abstract

Some rumen ciliates have endosymbiotic methanogens

Cited by 299 publications

References 20 publications

Effects of disodium fumarate on ruminal fermentation and microbial communities in sheep fed on high-forage diets

Effects of disodium fumarate on ruminal fermentation and microbial communities in sheep fed on high-forage diets

The effect and mode of action of saponins on the microbial populations and fermentation in the rumen and ruminant production

Effect of Mixed Microbial Culture on Fermentation of Beverage Residues and the Effect of the Fermented Beverage Residues on in Vitro Rumen Fermentation and Methane Production

Contact Info

Product

Resources

About