Survival ofMegasphaera elsdenii during starvation

Mink, Ronald W.; Hespell, Robert B.

doi:10.1007/bf01566598

Cited by 17 publications

(9 citation statements)

References 32 publications

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“…When Hespell and his colleagues studied the survival of Sefenomonas ruminantium (Mink and Hespell, 1981a), Ruminococcus flavefaciens (Wachenheim and Hespell, 1985), and Megasphaera efsdenii (Mink and Hespell, 1981b) the half-times of survival ranged from 2.5 to 13h. When Hespell and his colleagues studied the survival of Sefenomonas ruminantium (Mink and Hespell, 1981a), Ruminococcus flavefaciens (Wachenheim and Hespell, 1985), and Megasphaera efsdenii (Mink and Hespell, 1981b) the half-times of survival ranged from 2.5 to 13h.…”

Section: Starvationmentioning

confidence: 99%

The Rumen Microbial Ecosystem

Hobson¹,

Stewart²

1997

347

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Section: Starvationmentioning

confidence: 99%

The Rumen Microbial Ecosystem

Hobson¹,

Stewart²

1997

347

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“…Fermentation acids were quantitated by gas-liquid chromatography of the free acids (18) or of the butyl esters (20). Hydrogen aind other fermentation gases were measured by gas chromatography (18).…”

Section: MLmentioning

confidence: 99%

Fermentation of xylans by Butyrivibrio fibrisolvens and other ruminal bacteria

Hespell

Wolf

Bothast

1987

Appl Environ Microbiol

151

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The ability of Butyrivibriofibrisolvens and other ruminal bacteria (6 species, 18 strains) to ferment a crude xylan from wheat straw or to ferment xylans from larchwood or oat spelts was studied. Liquid cultures were monitored for carbohydrate utilization, cell growth (protein), and fermentation acid production. B.fibrisolvens 49, H17c, AcTF2, and Dl grew almost as well on one or more of the xylans as they did on cellobiose-maltose. B. fibrisolvens 12, R28, A38, X1OC34, ARD22a, and X6C61 exhibited moderate growth on xylans. Partial fermentation of xylans was observed with Bacteroides ruminicola B14, Bacteroides succinogenes S85, Ruminococcus albus 7, Ruminococcus flavefaciens C94 and FD1, and Succinivibrio dextrinosolvens 22B. All xylans tested appeared to have a small fraction of carbohydrate that supported low levels of growth of nonxylanolytic strains such as Selenomonas ruminantium HD4. Compared to growth on hexoses, the same array of fermentation acids was produced upon growth on xylans for most strains; however, reduced lactate levels were observed for B. fibrisolvens 49 and Selenomonas ruminantium HD4. Measurements of enzyme activities of B. fibrisolvens AcTF2, 49, H17c, and D1 indicated that the xylobiase activities were cell associated and that the xylanase activities were predominantly associated with the culture fluid. The pattern of expression of these enzymes varied both between strains and between the carbon sources on which the strains were grown.

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“…Depending upon the diet of an animal, soluble carbohydrate concentrations can become insufficient to support microbial growth within a few hours after the animal has been fed (12, 31). The results of investigations with selected pure cultures of soluble carbohydrate-fermenting rumen bacteria indicate that these bacteria have less capacity to endure periods of low nutrient availability than bacteria from other ecosystems do (18)(19)(20). Thus, cycles of bacterial growth and nonviability may exert an important influence on the overall ruminal microbial populations and energy economy.…”

mentioning

confidence: 99%

Responses of Ruminococcus flavefaciens , a Ruminal Cellulolytic Species, to Nutrient Starvation

Wachenheim

Hespell

1985

Appl Environ Microbiol

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Ruminococcusflavefaciens strain C94, a strictly anaerobic, cellulolytic ruminal bacterial species, was grown either in batch or continuous cultures (cellobiose limited or nitrogen limited) at various dilution rates. Washed cell suspensions were incubated anaerobically at 39°C without nutrients for various times up to 24 h. The effects of starvation on direct and viable cell counts, cell composition (DNA, RNA, protein, and carbohydrate), and endogenous production of volatile fatty acids by the cell suspensions were determined. In addition, the effect of the pH of the starvation buffer on direct and viable cell counts was determined. Survival of batch-grown cells during starvation was variable, with an average time for one-half the cells to lose viability (ST50) of 10.9 h. We found with continuous cultures that viable cell counts declined faster when the initial cell suspensions had been grown at faster dilution rates; this effect was more pronounced for suspensions that had been limited by cellobiose (ST50 = 6.6 h at a dilution rate of 0.33 h-') than for suspensions that had been limited by nitrogen (ST50 = 9.5 h at a dilution rate of 0.33 h-). With continuous cultures, viable cell counts in all cases declined faster than direct cell counts did. The rates of disappearance of specific cell components during starvation varied with the initial growth conditions, but could not be correlated with the loss of viability. Volatile fatty acid production by starving cells was very low, and acetate was the main product. Starved cells survived longer at pH 7.0 than they did at pH 5.5, and this effect of pH was greater for cellobiose-limited cells (mean ST50 = 7.1 h) than for nitrogen-limited cells (mean ST50 = 12 h). Although it has relatively low ST50 values, R.flavefaciens has sufficient survival abilities to maintain reasonable numbers in domestic animals having maintenance or greater feed intake.

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Survival ofMegasphaera elsdenii during starvation

Cited by 17 publications

References 32 publications

The Rumen Microbial Ecosystem

The Rumen Microbial Ecosystem

Fermentation of xylans by Butyrivibrio fibrisolvens and other ruminal bacteria

Responses of Ruminococcus flavefaciens , a Ruminal Cellulolytic Species, to Nutrient Starvation

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