Effects of condensed tannins on endoglucanase activity and filter paper digestion by Fibrobacter succinogenes S85

• Published in: Applied and Environmental Microbiology 1993-07, Vol.59 (7), p.2132-2138
• Main Authors: Bae, H D, McAllister, T A, Yanke, J, Cheng, K J, Muir, A D
• Format: Article
• Language: English
• Subjects: actividad enzimatica; activite enzymatique; bacteria; Bacteriology; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; Biotechnology; Cellular biology; cellulase; cellulolyse; cellulolysis; celulasa; celulolisis; enzymic activity; Fibrobacter succinogenes; Flowers & plants; Fundamental and applied biological sciences. Psychology; Lotus corniculatus; microorganisme; microorganismos; microorganisms; Mission oriented research; Physiology and Biotechnology; Physiology and metabolism; rumen; taninos; tannin; tannins
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/aem.59.7.2132-2138.1993

The effect of condensed tannins from birdsfoot trefoil (Lotus corniculatus L.) on the cellulolytic rumen bacterium Fibrobacter succinogenes S85 was examined. Condensed tannins inhibited endoglucanase activity in the extracellular culture fluid, at concentrations as low as 25 microgram ml(-1). In contrast, cell-associated endoglucanase activity increased in concentrations of condensed tannins between 100 and 300 microgram ml(-1). Inhibition of endoglucanase activity in both the extracellular and the cell-associated fractions was virtually complete at 400 microgram of condensed tannins ml(-1). Despite the sharp decline in extracellular endoglucanase activity with increasing concentrations of condensed tannins, filter paper digestion declined only moderately between 0 and 200 microgram of condensed tannins ml(-1). However, at 300 microgran ml(-1) filter paper digestion was dramatically reduced and at 400 microgram ml(-1), almost no filter paper was digested. F. succinogenes S85 was seen to form digestive grooves on the surface of cellulose, and at 200 microgram ml(-1), digestive pits were formed which penetrated into the interior of cellulose fibers. Cells grown with condensed tannins (100 to 300 microgram ml(-1) possessed large amounts of surface material, and although this material may have been capsular carbohydrate, its osmiophilic nature suggested that it had arisen from the formation of tannin-protein complexes on the cell surface. The presence of electron-dense extracellular material suggested that similar complexes were formed with extracellular protein.