The Rumen Microbial Ecosystem

Hobson, P. N.; Stewart, C. S.

doi:10.1007/978-94-009-1453-7

Cited by 347 publications

(30 citation statements)

References 891 publications

(1,383 reference statements)

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“…Like all mammals, ruminants lack the enzymes necessary to digest fiber (i.e., cellulose, hemicellulose) and instead rely on an internal ecosystem of anaerobic microorganisms to ferment these otherwise indigestible feed components [4]. Most microorganisms in the rumen and lower digestive tract use fermentation to fuel their cellular functions, and produce Short-Chain Fatty Acids (SCFAs) as a byproduct.…”

Section: Introductionmentioning

confidence: 99%

Effects of Spent Craft Brewers’ Yeast on Fermentation and Methane Production by Rumen Microorganisms

Pszczolkowski¹,

Bryant²,

Harlow³

et al. 2016

AiM

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Saccharomyces cerevisiae is a key component of beer brewing and a major by-product. The leftover, spent brewers' yeast from large breweries has been used as a protein supplement in cattle; however the possible advantages of spent yeast from smaller craft breweries, containing much higher levels of bioactive hop acids, have not been evaluated. Hops secondary metabolites from the hops (Humulus lupulus L.) used to make beer are concentrated in the yeast during brewing, and have antimicrobial activity against Gram-positive bacteria. Uncultivated suspensions of bovine rumen microorganisms produced less methane during fructose fermentation when exposed to inactivated, and freeze-dried spent craft brewers' yeast than a bakers' yeast control. The experiment was repeated with caprine rumen microorganisms and ground grass hay as the substrate. Likewise, in the presence of craft brewers' yeast less methane was produced (2.7% vs. 6.9% CH4). Both experiments also revealed a decrease in acetic acid production, but not propionic acid production, when craft brewers' yeast was included. These results indicated that spent yeast could represent a co-product for craft breweries, and a feed supplement for ruminants that has a favorable impact on methane production.

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Section: Introductionmentioning

confidence: 99%

Effects of Spent Craft Brewers’ Yeast on Fermentation and Methane Production by Rumen Microorganisms

Pszczolkowski¹,

Bryant²,

Harlow³

et al. 2016

AiM

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“…The rumen is a complex ecosystem containing billions of microorganisms including archaea, bacteria, protozoa, and fungi [1,2]. Many of these microbes are tightly attached to solid rumen content [3] and produce biomassdegrading enzymes [1].…”

Section: Introductionmentioning

confidence: 99%

“…Many of these microbes are tightly attached to solid rumen content [3] and produce biomassdegrading enzymes [1]. These naturally existing biomass degraders have attracted great interest by the scientific community due to their ability to convert complex lignocellulosic biomass into smaller molecules; and microbial enzymes from the cow rumen have been suggested for optimizing current industrial processes that produce lignocellulosic biofuels [4].…”

Section: Introductionmentioning

confidence: 99%

Improved Method for Isolation of Microbial RNA from Biofuel Feedstock for Metatranscriptomics

Piao¹,

Markillie²,

Culley³

et al. 2013

AiM

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Metatranscriptomics-gene express profiling via DNA sequencing-is a powerful tool to identify genes that are actively expressed and might contribute to the phenotype of individual organisms or the phenome (the sum of several phenotypes) of a microbial community. Furthermore, metatranscriptome studies can result in extensive catalogues of genes that encode for enzymes of industrial relevance. In both cases, a major challenge for generating a high quality metatranscriptome is the extreme lability of RNA and its susceptibility to ubiquitous RNAses. The microbial community (the microbiome) of the cow rumen efficiently degrades lignocelullosic biomass, generates significant amounts of methane, a greenhouse gas twenty times more potent than carbon dioxide, and is of general importance for the physiological wellbeing of the host animal. Metatranscriptomes of the rumen microbiome from animals kept under different conditions and from various types of rumen-incubated biomass can be expected to provide new insights into these highly interesting phenotypes and subsequently provide the framework for an enhanced understanding of this socioeconomically important ecosystem. The ability to isolate large amounts of intact RNA will significantly facilitate accurate transcript annotation and expression profiling. Here we report a method that combines mechanical disruption with chemical homogenization of the sample material and consistently yields 1 mg of intact RNA from 1 g of rumen-incubated biofuel feedstock. The yield of total RNA obtained with our method exceeds the RNA yield achieved with previously reported isolation techniques, which renders RNA isolated with the method presented here as an ideal starting material for metatranscriptomic analyses and other molecular biology applications that require significant amounts of starting material.

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“…While the ruminal microbiota is able to produce different B vitamins as well as vitamin K, Vit. E must be supplied with the feed (Williams & Coleman, 1997). In all feed, Naziroğlu et al (2002) have found minor but not sufficient amounts of Vit.…”

mentioning

confidence: 99%

Influence of vitamin E on organic matter fermentation, ruminal protein and fatty acid metabolism, protozoa concentrations and transfer of fatty acids

Schäfers¹,

Meyer²,

Soosten³

et al. 2018

Animal Physiology Nutrition

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Vitamin E (Vit. E) is discussed to influence ruminal biohydrogenation. The objective of this study was to investigate the influence of a Vit. E supplementation on rumen fermentation characteristics, ruminal microbial protein synthesis as well as ruminal organic matter fermentation. Furthermore, we aimed to investigate the influence of Vit. E supplementation on short-chain fatty acids (SCFA) and protozoa concentrations in the rumen and, in addition, on transfer rates of middle-chain and long-chain fatty acids into the duodenum in lactating dairy cows. Eight rumen and duodenum fistulated German Holstein cows were assigned to either a group receiving 2,327 IU/d Vit. E (138.6 IU/kg DM DL-α-tocopherylacetate; n = 4) or a control group (23.1 IU/kg DM; n = 4). Neither ruminal protein synthesis nor organic matter fermentation was influenced by treatment. Vit. E did not act on the concentrations of short-chain fatty acids and protozoa in rumen fluid. Duodenal flow of C13:0 (1.3 versus 0.2 g/d, p = 0.014) and iso-C14:0 (1.0 versus 0.5 g/d, p = 0.050) was higher in the Vit. E group. We observed a trend for higher duodenal flows for C12:0 (1.6 versus 0.9 g/d, p = 0.095) and anteiso-C15:0 (12.2 versus 8.9 g/d, p = 0.084). Transfer rate of C12:0 tended to be higher in the Vit. E group (125.61 versus 73.96, p = 0.082). No other transfer rates were affected by treatment. Further studies are necessary to investigate the influence of Vit. E on rumen microbiota and their fatty acid production as well as on the impact of different doses of Vit. E supplementation on variables of protein synthesis efficiency.

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The Rumen Microbial Ecosystem

Cited by 347 publications

References 891 publications

Effects of Spent Craft Brewers’ Yeast on Fermentation and Methane Production by Rumen Microorganisms

Effects of Spent Craft Brewers’ Yeast on Fermentation and Methane Production by Rumen Microorganisms

Improved Method for Isolation of Microbial RNA from Biofuel Feedstock for Metatranscriptomics

Influence of vitamin E on organic matter fermentation, ruminal protein and fatty acid metabolism, protozoa concentrations and transfer of fatty acids

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