The Journal of ProtozoologyVolume 27, Issue 2 p. 250-250 Alexander, M., Ed. 1979. Advances In Microbial Ecology, Vol. 3. Plenum Press, New York and London. Viii + 225 Pp. $24.50. R. E. HUNGATE, R. E. HUNGATE University of California Davis, California 95616.Search for more papers by this author R. E. HUNGATE, R. E. HUNGATE University of California Davis, California 95616.Search for more papers by this author First published: May 1980 https://doi.org/10.1111/j.1550-7408.1980.tb04692.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume27, Issue2May 1980Pages 250-250 RelatedInformation

A medium has been developed using alfalfa fiber as the sole substrate. It gave high culture counts (3 X 10(9) to 8 X 10(9)/ml) of rumen bacteria. When this medium was combined with the medium 98-5 of Bryant and Robinson, modified to contain 33% rumen fluid instead of 40% clarified rumen fluid, a higher count was obtained than with either medium alone.

Seven strains of isolated from the bovine rumen are described and their characteristics compared with those of strains described in the literature. On the basis of fermentation products two groups can be distinguished within this species. One group includes the type strain and is almost completely homofermentative. The other group includes strains that produce hydrogen, formate, butyrate and valerate in addition to lactate.

Seven strains ofEubacterium (Cillobacterium) cellulosolvens isolated from the bovine rumen are described and their characteristics compared with those of strains described in the literature. On the basis of fermentation products two groups can be distinguished within this species. One group includes the type strain and is almost completely homofermentative. The other group includes strains that produce hydrogen, formate, butyrate and valerate in addition to lactate.

The feed and feces of a continuously fed sheep were analyzed for carbon, hydrogen, and nitrogen, with oxygen as the remainder. The daily feed-feces weight difference was used as the reactant in an equation representing the rumen fermentation. The measured products were the daily production of volatile fatty acids (VFA), CH4, CO2, and ammonia. The carbon unaccounted for was assumed to be in the microbial cell material produced in the rumen and absorbed before reaching the feces. The ratio of C to H, O, and N in bacteria was used to represent the elemental composition of the microbes formed in the rumen fermentation, completing the following equation:C20.03H36.99O17.406N1.345 + 5.65 H2O → C12H24O10.1 + 0.83 CH4 VFA + 2.76 CO2 + 0.50 NH3 + C4.44H8.88O2.35N0.785 microbial cells absorbed With C arbitrarily balanced and O balanced by appropriate addition of water, any error is reflected in the H. The H recovery was 98.5%. The turnover rate constant for rumen liquid equilibrating with polyethylene glycol (PEG) was 2.27 per day. Direct counts and volume measurements of the individual types of bacteria and protozoa in the rumen were used to calculate the total microbial cell volume in the rumen, not equilibrating with it. The dry matter in the rumen (582 g) and the nitrogen content (12.05) of the microbes in the rumen were estimated, the latter constituting 85% of the measured N in the rumen. Calculations for rumen dry matter and nitrogen turning over at the PEG rate introduce big discrepancies with other parameters; a rumination pool must be postulated. Its size and composition are estimated. Arguments are presented to support the view that dry matter and some of the microbes, chiefly the protozoa, do not leave the rumen at the PEG rate. One experiment with the same sheep fed twice daily showed significantly less production of microbial cells than did the continuous (each 2 hr) feeding. Analysis of the microbial cell yield suggests that, on the basis of 11 mg of cells per adenosine triphosphate molecule, a maximum of six adenosine triphosphate molecules could have been formed from each molecule of hexose fermented.

A methanogenic enrichment culture decomposed small concentrations of 14 C-benzoate to 14 C 4 and 14 CO 2 under stringently anaerobic conditions with or without preceding exposure to benzoate.

This chapter presents factors that are considered in developing stringently anaerobic techniques and in describing the procedure and rationale of roll-tube method. A roll-tube method was developed in which agar medium was distributed as a thin layer over the internal surface of test tubes charged with an anaerobic atmosphere for the isolation of obligately anaerobic bacteria of the rumen. In the roll-tube method, exposure of bacteria and culture medium to air is avoided by displacing the air in the culture vessel with an oxygen-free gas, such as carbon dioxide, hydrogen, nitrogen, or mixtures of these gases. Carbon dioxide is the gas of choice because it is heavier than air, relatively cheap, and valuable in buffering. Vessels are stoppered under conditions preventing access of air. The cultures require no special incubators and can be removed and examined with no anaerobic precautions if kept stoppered. If opened, anaerobiosis can be continuously maintained during necessary manipulations, and the culture again closed without exposure to oxygen.

Occurrence of methane in gas from the human intestine is evidence that methanogenic organisms grow in the human alimentary tract. Both hydrogen and methane can be detected in the respired air of many humans (1). This note reports the results of experiments to detect methanogenic bacteria in feces and to isolate them in pure culture. Samples of fresh feces were suspended anaerobically in nine volumes of sterile distilled water and diluted through a series of tubes containing an agar mineral salts medium (2), plus 10% bovine rumen fluid and 10% of an extract of human feces. The feces extract was prepared by diluting fresh feces 10-fold with distilled water, and both the feces extract and the rumen fluid were filtered through Whatman no. 4 filter paper. The culture medium was prepared anaerobically under a mixture of 80% H2 and 20% CO2, as previously describedby Paynter and Hungate (3), and dispensed in 4.2-ml amounts into butyl rubber-stopper tubes. Before use, 0.05 ml of 3% cysteine hydrochloride, 0.25 ml of 10% sodium bicarbonate and 0.15 ml of H2S gas were added to each tube. The syringe method (R. E. Hungate, submitted for publication) was used in making dilutions and in all subcultures except when colonies were picked. Picking was performed with a drawnout bent Pasteur pipette with air excluded from the tube by gassing with the H2-CO2 mixture. Each 2 or 3 days the tubes were examined for a decrease in pressure that would indicate utilization of hydrogen and carbon dioxide according

A method for measuring the steady state concentration of hydrogen gas dissolved in rumen contents was developed, which consisted of equilibrating the intercellular fluid with sterile salt solution within a dialysis sac immersed in the rumen or in the in vitro system under study. After about 1 hr of equilibration the contents of the sac were withdrawn and transferred without loss of hydrogen to a flask devoid of materials except water and water vapor. Carbon dioxide was absorbed with alkali and the remaining gas displaced by boiling, with condensation of vapor in a water-cooled hypodermic syringe. The hydrogen was collected in the syringe and analyzed with a gas chromatograph.

Margherita , S. S. (University of California, Davis), R. E. Hungate, and Hannelore Storz . Variation in rumen Butyrivibrio strains. J. Bacteriol. 87: 1304–1308. 1964.—Five strains of Butyrivibrio isolated from the rumen of a single animal on an alfalfa hay ration were tested for serological relationships by agglutination and immunofluorescence. The main finding was a serological monospecificity of the strains. A cross-reaction between two strains was detected by agglutination and a second cross-reaction by immunofluorescence, but the cross-reacting pairs were different. Two years after the strains were isolated, fluorescein-conjugated antisera against three of them were used to test rumen contents of the same animal for homologous cell types. None was found. The findings indicate great variability in the serological characteristics of rumen butyrivibrios.

Margherita , S. S. (University of California, Davis) and R. E. Hungate . Serological analysis of Butyrivibrio from the bovine rumen. J. Bacteriol. 86: 855–860. 1963.—The cultural and fermentation characteristics of a number of strains of Butyrivibrio fibrisolvens isolated from the bovine rumen of cattle from different areas were determined, and the strains were subjected to serological analysis by the techniques of agglutination, immunodiffusion, and indirect hemolysis. In general, the results of the three methods agreed fairly well, but some variation was shown according to the method of preparation of the antigen. Much serological heterogeneity was disclosed. The greatest degree of agglutinating cross-reactivity was observed with strains isolated simultaneously from two animals in the same herd of African zebu cattle and with a Pullman strain. These cross-reactions were confirmed by immunodiffusion and indirect hemolysis tests. Agglutinating cross-reactions at low titers were observed between additional strains. The African isolates were shown to possess unique, as well as shared, antigens.

Hungate , R. E. (University of California, Davis). Polysaccharide storage and growth efficiency in Ruminococcus albus . J. Bacteriol. 86: 848–854. 1963.— Ruminococcus albus strain RAM requires biotin, p -aminobenzoic acid, pyridoxamine, isovalerate, isobutyrate, 2-methylbutyrate, and either cysteine or sulfide. Rumen fluid and casein hydrolysate improve growth but are not essential. Up to 35% iodophilic polysaccharide is stored in cells from batch cultures and 17% in a continuous culture on a 10-hr cycle. The storage product is a polymer of glucose resembling starch. The yield of cells in continuous culture, corrected for stored starch, averaged 102 mg per mmole of cellobiose fermented to waste products. It is postulated that nine high-energy phosphates are derived from each cellobiose molecule. Conversions providing this number are discussed.

High velocity constants for conversion of added succinate to propionate, together with estimations of pool size, showed that extracellular succinate is the major precursor of the propionate formed in the rumen. Some bacteria give off succinate as a final fermentation product which is decarboxylated by others to propionate.

Most natural habitats of microorganisms are difficult to analyze because of large and rapid changes in substrate, moisture, temperature, oxygen, and other factors of the physical environment. With the accompanying fluctuations in the microbiota the possible permutations and combinations of the environmental variables are so numerous that information obtained in one investigation is only questionably applicable in another. This situation is particularly evident in soil, the primary habitat of so many microbes. Certain habitats such as the bodies of plants and animals are more nearly constant. The defense mechanisms of the host prevent massive invasions by unselected species and the number of successful parasitic types at any one time is small. This facilitates ecological analysis and, because parasitism is so important in the human economy, a great body of knowledge on the ecology of parasitic microorganisms which penetrate the tissues of plants and animals has accumulated. This knowledge is almost exclusively qualitative in nature and of little help in understanding interrelationships in open systems containing a wide variety of forms.

1. Experiments are described in which retention time of digesta in the reticulo-rumen, fermentation rates of rumen contents, and dry-matter digestibilities were studied simultaneously in four grade European and three zebu steers.2. Fermentation rates and rumen retentions were significantly negatively correlated.3. Correlations between digestibility and the other two factors were not significant at a high level.4. The multiple regressions calculated for retention time and fermentation rate were significant at the 5% level and that for digestibility approached this level.5. While only fermentation rates show significant differences for the two types of cattle, the results suggest that grades and zebus differ also in the rate of passage of digesta through the rumen.6. The loss in weight of substrate per unit of fermentation products was measured inin vitroexperiments.7. Using certain assumptions, estimates are made of the extent to which the measured fermentation rates could account for the loss in weight of dry matter during digestion, and are compared with the loss actually found.

1. Statistics of several measured parameters are reported. They show that fermentation rates of rumen contents from zebu and European-type cattle in East Africa differ due to time of feeding, to individual animals, and to differences between zebu and grade.2. The fermentation products were determined as acid, CO2and methane. The proportion of methane showed an inverse correlation with the rate of fermentation.3. The mean fermentation rate showed a trend in the direction expected from the weight gains of the animals.