Cellulose digestion and cellulase regulation and distribution in Fibrobacter succinogenes subsp. succinogenes S85

Huang, Li; Forsberg, Cecil W.

doi:10.1128/aem.56.5.1221-1228.1990

Cited by 71 publications

(26 citation statements)

References 33 publications

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“…feedback mechanisms (Huang and Forsberg 1990;Teather and Ohmiya 1991). The B-glycosidase activities were depressed to a lesser extent than were polysaccharidases.…”

Section: Discussionmentioning

confidence: 95%

“…The drop in pH inside the bags to a value near 6.00 for high-concentrate diet may be responsible for a marked decrease in the proportion of fibrolytic microorganisms, due to the high susceptibility of the major fibrolytic rumen bacteria to acidification (Russell and Dombrowski 1980;Slyter 1986). Competition between fibrolytic and amylolytic bacteria for nitrogen and other 'necessary nutrients (Firkins et al 1991), and shifts in substrate utilisation by the non-obligate fibrolytic bacteria to the more readily fermentable carbohydrates (Huang and Forsberg 1990) may also be involved in the depression in the fibrolytic potential within the SAM. Substrate preference may be related to catabolite regulation involving end-product…”

Section: Discussionmentioning

confidence: 99%

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Effect of Barley Supplement on Microbial Fibrolytic Enzyme Activities and Cell Wall Degradation Rate in the Rumen

Nozière

Besle

Martin

et al. 1996

J. Sci. Food Agric.

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Three ruminally cannulated dry cows were used in a Latin square design to investigate the relationship between microbial fibrolytic enzyme activities and in saccocell wall degradation of two gramineous hays, in which cell wall content ranged from 510 g kg−1 DM for the regrowth to 687 g kg−1 DM for the late harvested hay. Animals were fed twice daily a diet consisting of wheat straw, cocksfoot hay and ground barley in the ratios 10: 90: 0 (w/w), 10: 60: 30 (w/w) and 10: 30: 60 (w/w). For each diet and each hay, thein saccodegradation of cell wall polysaccharides and phenolic acids was determined. After 2 h and 23 h incubation time in the rumen, pH was measured in the bags, and fibrolytic activities (xylanase, avicelase, β‐glycosidases) of the microbial population colonising haysin saccowere measured. Supplementation above 30% barley decreased the degradation rate of the cell wall polysaccharides, concomitantly with a decrease in polysaccharidase activities. The decrease in degradation rate was more marked for the regrowth than for the late harvested hay, for hemicelluloses than for cellulose and for ferulic than forp‐coumaric acid. These differences did not appear to be related to microbial activities, which were similar between hays and between polysaccharidases, but rather to differences in accessibility of cell wall components to microbial enzymes, related to the composition of the forage and the cell wall architecture.

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“…feedback mechanisms (Huang and Forsberg 1990;Teather and Ohmiya 1991). The B-glycosidase activities were depressed to a lesser extent than were polysaccharidases.…”

Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Effect of Barley Supplement on Microbial Fibrolytic Enzyme Activities and Cell Wall Degradation Rate in the Rumen

Nozière

Besle

Martin

et al. 1996

J. Sci. Food Agric.

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“…Since cells limited by ammonia or branched-chain volatile fatty acids also lost their ability to digest cellulose as soon as growth ceased, it appeared that only actively growing cells had crystalline cellulase activity. Miron et al (22) indicated that the cellulases of F. succinogenes S85 might be induced, but Hiltner and Dehority (11) and Huang and Forsberg (13) indicated that cells growing on cellobiose had as much cellulolytic activity as cells growing on cellulose. Our work indicated that cells grown on cellobiose could digest cellulose without a lag time, and this result indicated that crystalline cellulase activity did not require cellulose per se.…”

Section: Discussionmentioning

confidence: 99%

Kinetics of Cellulose Digestion by Fibrobacter succinogenes S85

Maglione¹,

Russell²,

Wilson³

1997

Appl Environ Microbiol

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Growing cultures of Fibrobacter succinogenes S85 digested cellulose at a rapid rate, but nongrowing cells and cell extracts did not have detectable crystalline cellulase activity. Cells that had been growing exponentially on cellobiose initiated cellulose digestion and succinate production immediately, and cellulose-dependent succinate production could be used as an index of enzyme activity against crystalline cellulose. Cells incubated with cellulose never produced detectable cellobiose, and cells that were preincubated for a short time with thiocellobiose lost their ability to digest cellulose (competitive inhibition [K i ] of only 0.2 mg/ml or 0.56 mM). Based on these results, the crystalline cellulases of F. succinogenes were very sensitive to feedback inhibition. Different cellulose sources bound different amounts of Congo red, and the binding capacity was HCl-regenerated cellulose > ball-milled cellulose > Sigmacel > Avicel > filter paper. Congo red binding capacity was highly correlated with the maximum rates of metabolism of cellulose digestion and inversely related to K m. Congo red (250 g/ml) did not inhibit the growth of F. succinogenes S85 on cellobiose, but this concentration of Congo red inhibited the rate of ball-milled cellulose digestion. A Lineweaver-Burk plot of ball-milled cellulose digestion rate versus the amount of cellulose indicated that Congo red was a competitive inhibitor of cellulose digestion (K i was 250 g/ml).

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“…The high specific activity of enzymes observed in underfed animals could be explained by the poor availability of easily degradable substrate in the rumen environment that would result in greater expression of the degradative potential of the solid-adherent microorganisms. In addition, invitro studies indicated the existence of negative feed- back of end-products of fibre degradation such as cellobiose and glucose on cellulase production and CMCase activity of cellulolytic microorganisms (Huang and Forsberg 1990;Piwonka and Firkins 1993). The poor availability of degradable substrates and the dilution of rumen contents that occurs when feeding level decreases (Doreau et a1 1986; Robinson et a1 1987) may have limited the expression of such an inhibition.…”

Section: Discussionmentioning

confidence: 99%

Enzyme activities of rumen solid‐adherent microorganisms in chronically underfed ewes

1994

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Four ruminally cannulated ewes were used in a series of two crossover designs to investigate the effects of underfeeding and of supplementation with slowly degradable protein on polysaccharide and glycoside-degrading enzyme activities in rumen solid-adherent microorganisms. The ewes were fed twice daily on a hay based diet to satisfy either 1.2 or 0.5 maintenance energy requirements, with or without 125 and 65 g fish meal supplement for the high and the low intakes, respectively. Enzyme preparations were isolated from rumen solid contents 2, 6, and 12 h after feeding. Protein supplementation had no significant effect on the activity of any of the enzymes measured. The effects of feeding level on carboxymethycellulase and xylanase activities were small, the specific activity (expressed per mg microbial protein) being slightly increased at low intake (P < 0.10). However, B-D-galactosidase, B-D-glucosidase, B-D-xylosidase, and B-D-cellobiosidase activities were considerably increased with low feeding level ( + 5 6 to +70% for specific activities; +31 to +50% when expressed per g dry matter). The activities of all enzymes tested increased significantly with time after feeding. The extent of specific activity response to variation of feeding level was greater for late sampling times than 2 h post-feeding. Ruminal degradation of the dietary hay was not affected by fish meal supplementation, but increased with reduction of feeding level ( + 59.7 g kg-' for neutral detergent fibre during the first 12 h of rumen incubation; P < 0.001). The higher microbial efficiency associated with greater retention time of feed particles in the rumen may account for the increase in cell wall degradation usually observed when feeding level declines.

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Cellulose digestion and cellulase regulation and distribution in Fibrobacter succinogenes subsp. succinogenes S85

Cited by 71 publications

References 33 publications

Effect of Barley Supplement on Microbial Fibrolytic Enzyme Activities and Cell Wall Degradation Rate in the Rumen

Effect of Barley Supplement on Microbial Fibrolytic Enzyme Activities and Cell Wall Degradation Rate in the Rumen

Kinetics of Cellulose Digestion by Fibrobacter succinogenes S85

Enzyme activities of rumen solid‐adherent microorganisms in chronically underfed ewes

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