The Rumen Protozoa

Certain nutritional requirements of isolates of sulfate-reducing bacteria were investigated. Isolates from environments other than digestors were able to grow and be maintained with 0.1 % yeast extract, while the isolates from sewage digestors were not. The latter required sewage digestor fluid in addition to 0.1 yeast extract and the sewage digestor fluid could be replaced by yeast extract in higher concentrations for most of the strains. Vitamins, mainly biotin, in the sewage digestor fluids or yeast extract were found to act as growth factors for these strains. Some isolates from sewage digestors could not be maintained with yeast extract even in high concentrations and required sewage digestor fluid.For pure culture of sulfate-reducing bacteria, yeast extract is usually added to the medium. PosTGATE (1) reported that ornithine, serine, and isoleucine in yeast extract acted as chelating agents. SKYRING et al. (2) reported that several isolates of Desulfovibrio species from marine, fresh water, and highly saline environments demanded growth factors including vitamins. In the previous report (3), we showed that addition of supernatant of sewage digestor fluid (4) to the medium which contained 0.1 % yeast extract resulted in a remarkable increase in viable counts of sulfate-reducers in sewage digestors, but did not affect the counts in the other enviornments such as water of rivers and drains. Sulfate-reducers in these environments were isolated and identified.Since relatively few studies on the nutritional requirement of sulfate-reducers have been carried out, clarification of the kinds of factors in the supernatant effective on the growth of sulfate-reducers is taxonomically significant. This will also provide new information for the improvement of culture conditions of sulfatereducers. In addition, our results on the enumeration of sulfate-reducers seemed to indicate a relationship between their nutritional requirements and habitats. The clarification of the difference in nutritional requirements of isolates from different 229

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“…It has been made clear that vitamins, VFAs, and hemin in the rumen juice act as growth factors for most of these strains (8).…”

Section: Discussionmentioning

confidence: 99%

Vitamin requirement of sulfate-reducers isolated from sewage digestor fluids.

Ueki

Suto

1981

J. Gen. Appl. Microbiol.

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“…In our preliminary experiments, we realized that bacteria making colonies under N2 gas phase were different from those under the CO2 gas phase in their morphology and Gram stain. It is well known that many kinds of bacteria such as Bacteroides and Streptococcus require CO2 essentially for theirr growth (2,17). Conversely, it has not been known that there exist some bacteria which are affected by the gaseous N2 other than N2-fixing bacteria.…”

Section: Discussionmentioning

confidence: 99%

Enumeration and Isolation of Anaerobic Bacteria in Sewage Digestor Fluids

Ueki

Miyagawa

Minato

et al. 1978

J. Gen. Appl. Microbiol.

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Examination of non-methanogenic anaerobic bacteria in sewage digestor fluid was attempted by the anaerobic roll tube method. For the enumeration of anaerobic bacteria in digestor fluid, rumen fluid-glucosecellobiose-agar (RGCA) gave as good results as previously reported in the rumen and other ecosystems like intestines and feces, under the 100% CO2 gas phase. However, under the mixed gas phase (95 % N2 and 5 % C02), higher colony counts were obtained with YLS agar, which contained the supernatant of autoclaved sewage digestor fluid, than with RGCA. Colony counts of anaerobic bacteria decreased with the progress of fermentation of waste and the proportion of facultative anaerobes in the isolated anaerobes also decreased. Large variations in the distribution pattern of bacteria were usually observed between the results obtained from three digestors investigated. However, Streptococcus and Gram-negative curved rods were commonly isolated from the three digestors as predominant groups.The anaerobic roll tube method devised by HUNGATE (1) facilitated isolation and cultivation of strictly anaerobic bacteria, and a significant progress has been made in the studies of microbial ecosystem in the rumen (2). This method was also applied to isolate anaerobic bacteria from intestines (3, 4) and feces (5, 6).However, application of this method to the enumeration and isolation of anaerobic bacteria in other ecosystems, such as the soil and sewage digestors has been very scarce. Our knowledge about anaerobic bacteria in these ecosystems is restricted to only a few kinds of bacteria and increase in the information about other anaerobic bacteria in these ecosystems is being expected.The anaerobic ecosystem of sewage digestor resembles that of rumen. The process of fermentation in digestors involves two stages, non-methanogenic and methanogenic. At the non-methanogenic stage, organic matters poured into digestors are decomposed to lower fatty acids and other low-molecular compounds. 317

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“…Several electron micrographs of rumen bacteria have also been published by Hungate (1966). However, most of the smaller organisms which form the bulk of the rumen population have not been described.…”

Section: Introduotionmentioning

confidence: 99%

Electron-Microscopic Investigation of the Flora of Sheep Alimentary Tract

Hoogenraad¹,

Hird²

1970

Aust. Jnl. Of Bio. Sci.

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SummaryDigesta from different regions of the sheep alimentary tract have been examined using electron microscopy. Direct examination of digesta from the rumen has revealed the presence of a number of phages and of a large variety of bacteria differing considerably in their morphology. An atlas of electron micrographs of these bacteria has been presented. The presence of large numbers of bacterial cell walls ;n the rumen indicates that the breakdown of bacteria commences in this organ. The major sites of digestion of bacteria are in the abomasum and small intestine where there is a substantial removal and modification of bacteria. INTRODUOTIONBacteria appear to undergo lysis in the rumen of sheep as indicated by the presence of large numbers of cell walls in any sample examined (Hoogenraad et al. 1967). Some of the factors responsible for such lysis have been indicated by Jarvis (1968). In addition it has been shown that rumen bacteria, and their cell walls, are susceptible to degradation under conditions similar to those existing in the alimentary tract of sheep and are digested during their passage through it .The present paper arose out of an attempt to follow such digestive processes by examining morphological changes in rumen bacteria as they pass along the alimentary tract. As an initial step, a detailed study of bacteria from rumen contents of sheep was undertaken using the electron microscope.In the studies of Moir and Masson (1952) by visual light microscopy, and of Smiles and Dobson (1955) by ultraviolet microscopy, many of the larger organisms found in the rumen were described. Several electron micrographs of rumen bacteria have also been published by Hungate (1966). However, most of the smaller organisms which form the bulk of the rumen population have not been described. Accordingly, we present electron micrographs of bacteria taken directly from rumen contents. Smiles and Dobson (1955) examined samples from rumen, omasum, and abomasum of sheep using ultraviolet microscopy and found that degenerative changes of various bacteria occur in the omasum and particularly the abomasum. To extend this study, samples from the rumen, omasum, abomasum, and different regions of the small intestine were inspected with the electron microscope to see whether degenerative changes also occur with the smaller bacteria. Parallel to this study, total bacterial counts were made by light microscopy.

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The Rumen Protozoa

Cited by 186 publications

References 0 publications

Vitamin requirement of sulfate-reducers isolated from sewage digestor fluids.

Vitamin requirement of sulfate-reducers isolated from sewage digestor fluids.

Enumeration and Isolation of Anaerobic Bacteria in Sewage Digestor Fluids

Electron-Microscopic Investigation of the Flora of Sheep Alimentary Tract

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