Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-30T05:54:14.515Z Has data issue: false hasContentIssue false

Polysaccharide synthesis and degradation by rumen micro-organisms in vitro

Published online by Cambridge University Press:  27 March 2009

J. K. Thompson
Affiliation:
School of Agriculture, Aberdeen
P. N. Hobson
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen

Summary

Micro-organisms from the rumen of a hay-fed sheep rapidly synthesized an intracellular polysaccharide (starch) when growing or resting suspensions of cells were incubated in vitro with easily metabolized sugars.

In 30 min incubation periods the optimum pH for the synthesis of starch by resting cultures was about 6·0 when glucose or fructose were substrates. Relative to glucose (as 100%) in ability to form the polysaccharide were, fructose, 75%; sucrose, 80%; soluble starch, 18·6%; maltose, 6·9%; cellobiose, 4%; and xylose, 2·1%. No starch was formed from galacturonic, acetic, propionic, butyric, lactic or succinic acids. A bacterial fraction of the microbes was reponsible for about 80% of the starch formed from glucose, fructose or sucrose.

In incubations of 24 h, resting cultures formed more starch per unit of microbial protein than growing cultures. The utilization of microbial starch and lactic acid, formation of which often accompanied starch synthesis, gave rise to volatile fatty acids. Acid production was maintained from these substrates at rates similar to those obtained from the fermentation of glucose. The acids were in molar proportions of 65–70% acetic, 20–27% propionic and 8–15% butyric. The maximum starch calculated to be synthesized by the microbes from 100 ml of rumen liquor, in media containing excess sugar, amounted to over 250 mg from glucose, 200 mg from fructose, 200 mg from cellobiose and 50 mg from xylose. It is calculated that under optimum conditions for synthesis about 25 g of starch would pass daily from the rumen of a sheep.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1971

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Allport, N. L. & Keyser, J. W. (1957). Colorimetric Analysis 1. London: Chapman and Hall Ltd.Google Scholar
Bryant, M. P., Small, N., Bouma, C. & Robinson, I. (1958). Studies on the composition of the ruminal flora and fauna of young calves. J. Dairy Sci. 41, 1747–67.CrossRefGoogle Scholar
Butterworth, J. P., Bell, S. E. & Garvock, M. G. (1960). Isolation and properties of the xylan-fermenting bacterium. 11. Biochem. J. 74, 180–82.CrossRefGoogle ScholarPubMed
Dische, Z. (1962). Color reactions of hexuronic acids. In Methods in Carbohydrate Chemistry 1 Ed. Whister, R. L. & Wolfrom, M. L.New York: Academic Press.Google Scholar
Doetsch, R. N., Howard, B. H., Mann, S. O. & Oxford, A. E. (1957). Physiological factors in the production of an iodophilic polysaccharide from pentose by a sheep rumen bacterium. J. gen. Microbiol. 16, 156–68.CrossRefGoogle ScholarPubMed
Doetsch, R. N., Robinson, R. G., Brown, R. E. & Shaw, J. C. (1953). Catabolic reactions of mixed suspensions of bovine rumen bacteria. J. Dairy Sci. 36, 825–31.CrossRefGoogle Scholar
Forsyth, G. & Hirst, E. L. (1953). Protozoal Polysaccharides. Structure of the polysaccharide produced by the holotrich ciliates present in sheep's rumen.J. chem. Soc. 2132–35.Google Scholar
Gibbons, R. J., Doetsch, R. N. & Shaw, J. C. (1955). Further studies on polysaccharide production by bovine rumen bacteria. J. Dairy Sci. 38, 1147–54.CrossRefGoogle Scholar
Gray, F. V., Pilgrim, A. F., Rodda, H. J. & Weller, R. A. (1952). Fermentation in the rumen of the sheep. IV. The nature and origin of the volatile fatty acids in the rumen of the sheep. J. exp. Biol. 29, 5765.CrossRefGoogle Scholar
Gutierrez, J. (1955). Experiments on the culture and physiology of holotrichs from the bovine rumen. Biochem. J. 60, 516–22.CrossRefGoogle Scholar
Heald, P. J. (1951). The assessment of glucose-containing substances in rumen micro-organisms during a digestion cycle in sheep. Br. J. Nutr. 5, 8493.CrossRefGoogle Scholar
Heald, P. J. & Oxford, A. E. (1953). Fermentation of soluble sugars by anaerobic holotrieh ciliate protozoa of the genera isotricha and dasytricha. Biochem. J. 53, 506–12.CrossRefGoogle ScholarPubMed
Hobson, P. N. (1965). Continuous culture of some anaerobic and facultatively anaerobic rumen bacteria. J. gen. Microbiol. 38, 167–80.CrossRefGoogle ScholarPubMed
Hobson, P. N. & Mann, S. O. (1955). Some factors affecting the formation of iodophilic polysaccharide in Group D streptococci from the rumen. J. Gen. Microbiol. 13, 420–35.CrossRefGoogle Scholar
Hobson, P. N. & Thompson, J. K. (1970). The concentration of soluble polysaceharides in the rumen contents of sheep fed on hay. J. agric. Sci., Gamb. 75, 471–78.CrossRefGoogle Scholar
Hopgood, M. F. & Walker, D. J. (1967). Succinic acid production by rumen bacteria. 1. Isolation and metabolism of Ruminococcus flavefaciens. Attst. J. biol. Sci. 20, 165–82.Google ScholarPubMed
Howard, P. H. (1955). Ruminal fermentation of pentosan. Biochem. J. 60, i.Google ScholarPubMed
Howard, B. H. (1961). Fermentation of pectin by rumen bacteria. Proc. Nutr. Soc. 20, xxix.Google Scholar
Hungate, R. E. (1943). Further experiments on cellulose digestion by the protozoa in the rumen of cattle. Biol. Bull. mar. biol. Lab. Woods Hole, 84, 157–63.CrossRefGoogle Scholar
Hungate, R. E. (1963). Polysaccharide storage and growth efficiency in Ruminococcus albus. J. Bact. 86 848–54.Google ScholarPubMed
Hungate, R. E. (1966). The Rumen and its Microbes. New York: Academic Press.Google Scholar
Johnson, R. R. (1966). Techniques and procedures for in vitro and in vivo rumen studies. J. Anim. Sci. 25, 855–75.CrossRefGoogle ScholarPubMed
McNaught, M. L. (1951). The utilization of non-protein nitrogen in the bovine rumen. 7. A qualitative and quantitative study of the breakdown of carbohydrate which accompanies protein formation in bovine rumen contents during in vitro incubation. Biochem. J. 49, 325–32.CrossRefGoogle Scholar
MacRae, J. C. & Armstrong, D. G. (1969). Studies on intestinal digestion in sheep. 2. Digestion of some carbohydrate constituents in hay, cereal and haycereal rations. Br. J. Nutr. 23, 377–87.CrossRefGoogle ScholarPubMed
Nelson, N. (1944). A photometric adaptation of the Somogyi method for the determination of glucose. J. biol. Ghem. 153, 375–80.CrossRefGoogle Scholar
Oxford, A. E. (1951). The conversion of certain soluble sugars to a glucosan by holotrich ciliates in the rumen of sheep. J. gen. Microbiol. 5, 8390.CrossRefGoogle ScholarPubMed
Packett, L. V. & McCune, R. W. (1965). Determination of stream-volatile organic acids in fermentation media by gas-liquid chromatography. Appl. Microbiol. 13, 22–7.CrossRefGoogle ScholarPubMed
Somogyi, M. (1952). Notes on sugar determination. J. biol. Chem. 185, 1923.CrossRefGoogle Scholar
Thomas, G. J. (1960). Metabolism of the soluble carbohydrates of grasses in the rumen of sheep. J. agric. Sci. Camb. 54, 360–72.CrossRefGoogle Scholar
Topps, J. H., Kay, R. N. B. & Goodall, E. D. (1968). Digestion of concentrate and hay diets in the stomach and intestines of ruminants. 1. Sheep. Br. J. Nutr. 22, 261–80.CrossRefGoogle Scholar
Trevelyan, W. E. & Harrison, J. S. (1952). Studies on yeast metabolism. 1. Fractionation and microdetermination of cell carbohydrates. Biochem. J. 50, 298309.CrossRefGoogle Scholar
Weller, R. A. & Gray, F. V. (1954). The passage of starch through the stomach of the sheep. J. Anim. Sci. 27, 824–26.Google Scholar
Winter, K. A., Johnson, R. R. & Dehority, B. A. (1964). Metabolism of urea nitrogen by mixed cultures of rumen bacteria grown on cellulose. J. Dairy Sci. 47, 739–97.CrossRefGoogle Scholar