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. 1989 May;55(5):1066–1073. doi: 10.1128/aem.55.5.1066-1073.1989

Fermentation products and plant cell wall-degrading enzymes produced by monocentric and polycentric anaerobic ruminal fungi.

W S Borneman 1, D E Akin 1, L G Ljungdahl 1
PMCID: PMC184255  PMID: 2757372

Abstract

Five anaerobic fungal isolates from the bovine rumen were grown on Coastal Bermuda grass (CBG) leaf blades and monitored over a 9-day period for substrate utilization, fermentation products, cellulase, and xylanase activities. Two of the fungal isolates showed monocentric growth patterns; one (isolate MC-1) had monoflagellated zoospores and morphologically resembled members of the genus Piromyces; the other (isolate MC-2) had multiflagellated zoospores and resembled members of the genus Neocallimastix. Three other isolates (PC-1, PC-2, and PC-3) exhibited polycentric growth and have not yet been described in the literature; these isolates were characterized by differences in morphology. All of the isolates degraded CBG to approximately the same extent (70% [dry weight]) in 9 days. Fermentation product accumulation was concurrent with substrate utilization. The major fermentation products for all isolates were formate, acetate, D-(-)-lactate, L-(+)-lactate, ethanol, carbon dioxide, and hydrogen. Succinate was produced by all cultures, with the exception of MC-1. Fermentation balances revealed different profiles for each isolate. As a group, monocentric isolates produced a greater ratio of oxidized to reduced products when grown on glucose or CBG than did the polycentric isolates, which produced a nearly equal ratio of these products. All isolates exhibited cellulolytic and xylanolytic activities, including endoglucanase, exoglucanase, beta-glucosidase, xylanase, and beta-xylosidase activities. Increasing enzyme activity correlated with the accumulation of fermentation products and substrate utilization. The optimum pH for the enzymatic activity of polycentric isolates was within a more narrow range (pH 6.4 to 7.0) than that of the monocentric isolates (pH 5.5 to 7.5). Activity toward cellulosic substrates was not detected until after the disappearance of reducing sugars. Xylanase activity was found to be five to seven times that of carboxymethyl cellulase activity for all cultures grown on CBG.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Akin D. E., Benner R. Degradation of polysaccharides and lignin by ruminal bacteria and fungi. Appl Environ Microbiol. 1988 May;54(5):1117–1125. doi: 10.1128/aem.54.5.1117-1125.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Akin D. E., Borneman W. S., Windham W. R. Rumen fungi: morphological types from Georgia cattle and the attack on forage cell walls. Biosystems. 1988;21(3-4):385–391. doi: 10.1016/0303-2647(88)90037-8. [DOI] [PubMed] [Google Scholar]
  3. Akin D. E., Gordon G. L., Hogan J. P. Rumen bacterial and fungal degradation of Digitaria pentzii grown with or without sulfur. Appl Environ Microbiol. 1983 Sep;46(3):738–748. doi: 10.1128/aem.46.3.738-748.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Akin D. E., Rigsby L. L. Mixed fungal populations and lignocellulosic tissue degradation in the bovine rumen. Appl Environ Microbiol. 1987 Sep;53(9):1987–1995. doi: 10.1128/aem.53.9.1987-1995.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Almin K. E., Eriksson K. E. Enzymic degradation of polymers. I. Viscometric method for the determination of enzymic activity. Biochim Biophys Acta. 1967 Jul 11;139(2):238–247. doi: 10.1016/0005-2744(67)90028-9. [DOI] [PubMed] [Google Scholar]
  6. Bauchop T., Mountfort D. O. Cellulose fermentation by a rumen anaerobic fungus in both the absence and the presence of rumen methanogens. Appl Environ Microbiol. 1981 Dec;42(6):1103–1110. doi: 10.1128/aem.42.6.1103-1110.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Bauchop T. Rumen anaerobic fungi of cattle and sheep. Appl Environ Microbiol. 1979 Jul;38(1):148–158. doi: 10.1128/aem.38.1.148-158.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
  9. Caldwell D. R., Bryant M. P. Medium without rumen fluid for nonselective enumeration and isolation of rumen bacteria. Appl Microbiol. 1966 Sep;14(5):794–801. doi: 10.1128/am.14.5.794-801.1966. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Gold J. J., Heath I. B., Bauchop T. Ultrastructural description of a new chytrid genus of caecum anaerobe, Caecomyces equi gen. nov., sp. nov., assigned to the Neocallimasticaceae. Biosystems. 1988;21(3-4):403–415. doi: 10.1016/0303-2647(88)90039-1. [DOI] [PubMed] [Google Scholar]
  11. Lever M. A new reaction for colorimetric determination of carbohydrates. Anal Biochem. 1972 May;47(1):273–279. doi: 10.1016/0003-2697(72)90301-6. [DOI] [PubMed] [Google Scholar]
  12. Lowe S. E., Theodorou M. K., Trinci A. P. Cellulases and xylanase of an anaerobic rumen fungus grown on wheat straw, wheat straw holocellulose, cellulose, and xylan. Appl Environ Microbiol. 1987 Jun;53(6):1216–1223. doi: 10.1128/aem.53.6.1216-1223.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Lowe S. E., Theodorou M. K., Trinci A. P. Growth and fermentation of an anaerobic rumen fungus on various carbon sources and effect of temperature on development. Appl Environ Microbiol. 1987 Jun;53(6):1210–1215. doi: 10.1128/aem.53.6.1210-1215.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Mountfort D. O., Asher R. A. Production and regulation of cellulase by two strains of the rumen anaerobic fungus Neocallimastix frontalis. Appl Environ Microbiol. 1985 May;49(5):1314–1322. doi: 10.1128/aem.49.5.1314-1322.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Orpin C. G. Studies on the rumen flagellate Neocallimastix frontalis. J Gen Microbiol. 1975 Dec;91(2):249–262. doi: 10.1099/00221287-91-2-249. [DOI] [PubMed] [Google Scholar]
  16. Orpin C. G. Studies on the rumen flagellate Sphaeromonas communis. J Gen Microbiol. 1976 Jun;94(2):270–280. doi: 10.1099/00221287-94-2-270. [DOI] [PubMed] [Google Scholar]
  17. Orpin C. G. The rumen flagellate Piromonas communis: its life-history and invasion of plant material in the rumen. J Gen Microbiol. 1977 Mar;99(1):107–117. doi: 10.1099/00221287-99-1-107. [DOI] [PubMed] [Google Scholar]
  18. Pearce P. D., Bauchop T. Glycosidases of the rumen anaerobic fungus Neocallimastix frontalis grown on cellulosic substrates. Appl Environ Microbiol. 1985 May;49(5):1265–1269. doi: 10.1128/aem.49.5.1265-1269.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Phillips M. W., Gordon G. L. Sugar and polysaccharide fermentation by rumen anaerobic fungi from Australia, Britain and New Zealand. Biosystems. 1988;21(3-4):377–383. doi: 10.1016/0303-2647(88)90036-6. [DOI] [PubMed] [Google Scholar]
  20. Sleat R., Mah R. A. Quantitative method for colorimetric determination of formate in fermentation media. Appl Environ Microbiol. 1984 Apr;47(4):884–885. doi: 10.1128/aem.47.4.884-885.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]

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