Current Microbiology

, Volume 24, Issue 1, pp 55–59

Synthesis and release of proteases byBacteroides fragilis

  • George T. Macfarlane
  • Sandra Macfarlane
  • Glenn R. Gibson


Protease production byBacteroides fragilis ATCC 25285 was determined in batch and continuous cultures. During exponential growth in batch culture, the majority of proteolysis was cell associated. However, as the bacteria reached stationary phase, most of the intracellular proteases were released into the culture medium. Measurements of alkaline phosphatase and β-galactosidase, which are respectively periplasmic and cytoplasmic marker enzymes inB. fragilis, showed that secretion of proteases in the stationary phase was a discrete event and was not associated with a general release of cytoplasmic contents. When the bacterium was grown in continuous culture, cell-associated protease activity increased concomitantly with dilution rate (D=0.03–0.23/h). The ratio of intracellular to whole cell protease activity also increased with growth rate (1∶1 at D=0.03/h; 1∶1.7 at D=0.23/h). Extracellular protease activity was detected only in trace amounts in continuous cultures at the lowest dilution rate. Determinations of the distribution of extracellular protease activity in batch culture after 48 h incubation showed that the majority of proteolysis (ca. 90%) was soluble. Nevertheless, a proportion was associated with particulate fractions, which had high specific activities.


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Literature cited

  1. 1.
    Barrett AJ (1977) Enzyme and metabolic inhibitors, vol. 2. New York: Academic Press, pp 721–795Google Scholar
  2. 2.
    Berg JO (1981) Cellular localization of glycoside hydrolases inBacteroides fragilis type bacteria. Curr Microbiol 5:13–17Google Scholar
  3. 3.
    Englyst HN, Hay S, Macfarlane GT (1987) Polysaccharide breakdown by mixed populations of human faecal bacteria. FEMS Microbiol Ecol 95:163–171Google Scholar
  4. 4.
    Finegold SM, Sutter VL, Mathisen GE (1983) Normal indigenous intestinal microflora. In: Hentges DJ (ed) Human intestinal microflora in health and disease. London: Academic Press, pp 3–31Google Scholar
  5. 5.
    Gibson SAW, Macfarlane GT (1988) Studies on the proteolytic activity ofBacteroides fragilis. J Gen Microbiol 134:19–27PubMedGoogle Scholar
  6. 6.
    Gibson SAW, Macfarlane GT (1988) Characterization of proteases formed byBacteroides fragilis. J Gen Microbiol 134:2231–2240PubMedGoogle Scholar
  7. 7.
    Gibson SAW, Mcfarlan C, Hay S, Macfarlane GT (1989) Significance of microflora in proteolysis in the colon. Appl Environ Microbiol 55:679–683PubMedGoogle Scholar
  8. 8.
    Ginsburg I (1985) Streptococcal enzymes and virulence. In: Holder IA (ed) Bacterial enzymes and virulence. Boca Raton, FL: CRC Press, pp 121–144Google Scholar
  9. 9.
    Hausmann E, Kaufman E (1969) Collagenase activity in a particulate fraction fromBacteroides melaninogenicus. Biochim Biophys Acta 194:612–615PubMedGoogle Scholar
  10. 10.
    Holdeman LV, Cato EP, Moore WEC (eds) (1977) Anaerobic laboratory manual, 4th edn. Blacksburg: Virginia Polytechnic Institute and State UniversityGoogle Scholar
  11. 11.
    Keith SM, Herbert RA (1983) Dissimilatory nitrate reduction by a strain ofDesulfovibrio desulfuricans. FEMS Microbiol Lett 18:55–59Google Scholar
  12. 12.
    Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (1953) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275Google Scholar
  13. 13.
    Macfarlane GT, Englyst HN (1986) Starch utilisation by the human large intestinal microflora. J Appl Bacteriol 60:195–201PubMedGoogle Scholar
  14. 14.
    Macfarlane GT, Gibson GR (1991) Formation of glycoprotein degrading enzymes byBacteroides fragilis. FEMS Microbiol Lett 77:289–294Google Scholar
  15. 15.
    Macfarlane GT, Macfarlane S (1991) Utilization of pancreatic trypsin by proteolytic and non-proteolyticBacteroides fragilis-type bacteria. Curr Microbiol 23:143–148Google Scholar
  16. 16.
    Macy JM, Probst I (1979) The biology of gastrointestinalBacteroides. Annu Rev Microbiol 33:561–594PubMedGoogle Scholar
  17. 17.
    Matsubara H, Feder J (1971) Other bacterial, mold and yeast proteases. In: Boyer PD (ed) The enzymes, vol. 3. New York: Academic Press, pp 721–795Google Scholar
  18. 18.
    Morihara K, Homma JY (1985)Pseudomonas proteases. In: Holder IA (ed) Bacterial enzymes and virulence. Boca Raton, FL: CRC Press, pp 41–79Google Scholar
  19. 19.
    Riepe SP, Goldstein J, Alpens DH (1980) Effect of secretedBacteroides proteases on human intestinal brush border enzymes. J Clin Invest 66:314–322PubMedGoogle Scholar
  20. 20.
    Salyers AA (1984)Bacteroides of the human lower intestinal tract. Annu Rev Microbiol 38:293–313PubMedGoogle Scholar
  21. 21.
    Smalley JW, Birss AJ (1987) Trypsin-like enzyme activity of the extracellular membrane vesicles ofBacteroides gingivalis W50. J Gen Microbiol 133:2883–2894PubMedGoogle Scholar
  22. 22.
    Webb JL (1966) Enzyme and metabolic inhibitors, vol. 2. New York: Academic Press, pp 729–985Google Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • George T. Macfarlane
    • 1
  • Sandra Macfarlane
    • 1
  • Glenn R. Gibson
    • 1
  1. 1.MRC Dunn Clinical Nutrition CentreCambridgeUK

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