ABSTRACT: Robert Hungate, considered the father of rumen microbiology, was the fi rst to initiate a systematic exploration of the microbial ecosystem of the rumen, but he was not alone. The techniques he developed to isolate and identify cellulose-digesting bacteria from the rumen have had a major impact not only in delineating the complex ecosystem of the rumen but also in clinical microbiolog...

Effects of two microbial feed supplements on microbial activities in rumen-stimulating cultures and the rumens of steers fed a fescue hay-based roughage diet were evaluated. The yeast culture supplement contained Saccharomyces cerevisiae (1.4 to 4.2 x 10(9) colony-forming units [cfu]/g), whereas the mixed microbial supplement contained yeast, lactobacilli and enterococci (1.4 to 2.7 x 10(9) cfu...

In dual outflow continuous fermenters on a 75:25 hay/barley diet, feed degradation and protein synthesis by mixed rumen microbes were tested in relation to the concentrations of HPO4(2-), HCO3- and Cl- and Na+/K+ ratio in artificial saliva, by applying a 16-run Franquart design, and by fitting second-order polynomial models. The HPO4(2-), HCO3-, Cl- concentrations and Na+/K+ ratio ranged from 0...

Screening of bovine rumen contents for heat-resistant and micro-aerophilic cellulose-degrading microorganisms was performed on carboxymethyl cellulose (CMC) plates at 37 °C-45 °C, and many isolates were found to produce reducing sugars under a static condition. Of those isolates, R8 and R15, which efficiently produced reducing sugars from CMC at a high temperature, were further examined. Taxono...

I t has been generally assumed that the nutritive value of protein feeds for ruminant animals is not influenced by the chemical and physical properties of the proteins. Several recent investigations have shown that proteins with a high solubility are degraded in the rumen to ammonia at a rate too rapid for efficient utilization. The rumen micro-organisms can then utilize only a relatively small...

In vitro fermentation experiments and a feeding trial were conducted to determine how distillers byproducts impact rumen microbiology and metabolism. The in vitro rate of lactic acid disappearance was not stimulated by direct addition of distillers byproducts to mixed rumen contents collected from a steer adapted to a high concentrate diet. However, if animals were fed condensed distillers bypr...

I. The effect of oxygen on the fermentation of sucrose by mixed rumen micro-organisms in vitro was studied by adding oxygen to the gas phase in three ways: at the beginning of incubation, at two hourly intervals during incubation and continuously. 2. The additions of oxygen had no measurable effect on the utilization of sucrose or on the production of carbon dioxide, steam-volatile acids and pa...

Mechanistic models of microbial metabolism in the rumen aim at an improved understanding and integration for research purposes or at an improved prediction for practical purposes. The standard way of representing such models is the rate : state formalism. The system is defined by a number of state variables and a set of differential equations describe the change of the state variables with time...

DNA based methods have been widely used to study the complexity of the rumen microbiota, and it is well known that the method of DNA extraction is a critical step in enabling accurate assessment of this complexity. Rumen fluid (RF) and fibrous content (FC) fractions differ substantially in terms of their physical nature and associated microorganisms. The aim of this study was therefore to asses...

Genomic analysis of Clostridium sp. NCR, an anaerobic Gram positive bacterium which was isolated from rumen fluid of Mehsani breed of buffalo revealed presence of various environmental gene tags (EGTs) involved in pathways for utilizing a wide range of substrates. Here we report the sequence of this rumen isolate, its whole genome sequence has been deposited in DDBJ/EMBL/GenBank under the acces...