Cell Envelope Morphology of Rumen Bacteria

Costerton, J. W.; Damgaard, H. N.; Cheng, K.-J.

doi:10.1128/jb.118.3.1132-1143.1974

Cited by 82 publications

(32 citation statements)

References 46 publications

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“…Past examination by electron microscopy revealed that P. ruminicola accumulated large amounts of electron-light carbohydrate in its cytoplasm and some cells was nearly completely filled with this material (5). Based on chemical and enzymatic characterization, the present study showed that the polysaccharide produced was glycogen with a molecular weight of over 2 ϫ 10 6 and an average chain length of 8 glucosyl units, both of which were in the range for glycogen found in mammalian and other bacterial cells (2,7,36).…”

Section: Discussionsupporting

confidence: 50%

“…The predominance of this particular organism is partially explained by its ability to use a variety of carbon and nitrogen sources and its highly efficient energy metabolism (11). Previous work showed that P. ruminicola accumulated large amounts of intracellular polysaccharide granules which disappeared several hours later after reaching the stationary phase (5,11). Recent studies (26,27) demonstrated that the organism accumulated polysaccharide under nitrogen-limiting and glucose-excess conditions in batch as well as continuous cultures.…”

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confidence: 99%

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Glycogen Formation by the Ruminal Bacterium Prevotella ruminicola

Lou¹,

Dawson²,

Strobel³

1997

Appl Environ Microbiol

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Prevotella ruminicola is an important ruminal bacteria. In maltose-grown cells, nearly 60% of cell dry weight consisted of high-molecular-weight (>2 ؋ 10 6 ) glycogen. The ratio of glycogen to protein (grams per gram) was relatively low (1.3) during exponential growth, but when cell growth slowed during the transition to the stationary phase, the ratio increased to 1.8. As much as 40% of the maltose was converted to glycogen during cell growth. Glycogen accumulation in glucose-grown cells was threefold lower than that in maltose-grown cells. In continuous cultures provided with maltose, much less glycogen was synthesized at high (>0.2 per h) than at low dilution rates, where maltose was limiting (28 versus 60% of dry weight, respectively). These results indicated that glycogen synthesis was stimulated at low growth rates and was also influenced by the growth substrate. In permeabilized cells, glycogen was synthesized from [ 14 C]glucose-1-phosphate but not radiolabelled glucose, indicating that glucose-1-phosphate is the initial precursor of glycogen formation. Glycogen accumulation may provide a survival mechanism for P. ruminicola during periods of carbon starvation and may have a role in controlling starch fermentation in the rumen.

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Section: Discussionsupporting

confidence: 50%

mentioning

confidence: 99%

Glycogen Formation by the Ruminal Bacterium Prevotella ruminicola

Lou¹,

Dawson²,

Strobel³

1997

Appl Environ Microbiol

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“…The bacterial morphology was quite distinct as a result of the presence of capsule, smooth cell envelope, glycogen, and poly-,f-hydroxybutyric acid granules. DISCUSSION Occurrence of different types of bacteria in pure culture is common (1,8,11,35), but ultrastructural and functional characterization of such types has been made only in recent years (10,12,22,27). In R. japonicum strains very little progress has been made along these lines.…”

Section: Resultsmentioning

confidence: 99%

Ultrastructure of Rhizobium japonicum in relation to its attachment to root hairs

Bal¹,

Shantharam²,

Ratnam³

1978

J Bacteriol

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In Rhizobiumjaponicum strain Nitragin 61A76, morphologically distinct types of bacteria were found to occur in yeast extract-mannitol broth cultures, at both mid-log and stationary phases. Of these only the capsular form, characterized by a smooth cell envelope, storage granules (glycogen and poly-,8-hydroxybutyric acid), and an amorphous extracellular capsule, bound soybean lectin. The binding site was localized in the capsular material. Less than 1% of the bacterial population differentiated into these capsular forms, which were also able to attach to the soybean root hair surface.

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“…Disruption of the glycocalyx prevents bacterial attachment (Latham, 1980). The glycocalyces of R. flavefaciens and R. albus are notably thicker than that of F. succinogenes (Costerton et al, 1974;Latham, 1980), and the factors that mediate attachment in these organisms have been shown to differ (Cheng et al, 1983/84;Morris, 1988;Roger et al, 1990).…”

Section: Attachment To Fibermentioning

confidence: 99%

Microbial attachment and feed digestion in the rumen

McAllister¹,

Bae²,

Jones

et al. 1994

Journal of Animal Science

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494

373

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Direct microscopic examination of the rumen and its contents shows microbial populations largely attached to feed particles in the digesta. Most feeds contain a surface layer that is resistant to attachment and therefore to digestion. Infiltration of these recalcitrant epidermal layers through damage sites or through focused enzymatic attack is essential for initiation of the digestive process. Proliferation of primary colonizing cells produces glycocalyx-enclosed microcolonies. Secondary colonizers from the ruminal fluid associate with microcolonies, resulting in the formation of multispecies microbial biofilms. These metabolically related organisms associate with their preferred substrates and produce the myriad of enzymes necessary for the digestion of chemically and structurally complex plant tissues. Upon accessing the internal, enzyme-susceptible tissues, microbial "digestive consortia" attach to a variety of nutrients, including protein, cellulose, and starch and digest insoluble feed materials from the inside out. Substances that prevent microbial attachment or promote detachment (e.g., condensed tannins, methylcellulose) can completely inhibit cellulose digestion. As the microbial consortium matures and adapts to a particular type of feed, it becomes inherently stable and its participant microorganisms are notoriously difficult to manipulate due to the impenetrable nature of biofilms. Properties of feed that place constraints on microbial attachment and biofilm formation can have a profound effect on both the rate and extent of feed digestion in the rumen. Developments in feed processing (i.e., chemical and physical), plant breeding, and genetic engineering (both of ruminal microorganisms and plants) that overcome these constraints through the promotion of microbial attachment and biofilm formation could substantially benefit ruminant production.

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Cell Envelope Morphology of Rumen Bacteria

Cited by 82 publications

References 46 publications

Glycogen Formation by the Ruminal Bacterium Prevotella ruminicola

Glycogen Formation by the Ruminal Bacterium Prevotella ruminicola

Ultrastructure of Rhizobium japonicum in relation to its attachment to root hairs

Microbial attachment and feed digestion in the rumen

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