PHOSPHORYLATION OF CELLOBIOSE AND GLUCOSE BY
            <i>RUMINOCOCCUS FLAVEFACIENS</i>

Ayers, W. A.

doi:10.1128/jb.76.5.515-517.1958

Cited by 64 publications

(21 citation statements)

References 5 publications

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“…Hungate (1963) predicted that high yields of bacterial cells on cellobiose could be attributed to the action of cellobiose phosphorylase. Ruminococcus flavefaciens also had a high yield on cellobiose and possesses cellobiose phosphorylase activity (Ayers 1958).…”

Section: Discussionmentioning

confidence: 99%

Increase of ruminal fiber digestion by cellobiose and a twin strain of Saccharomyces cerevisiae live cells in vitro

Lila

Mohammed

Takahashi

et al. 2006

Animal Science Journal

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This experiment was designed to investigate the effects of different concentrations of cellobiose (CB) or a twin strain of Saccharomyces cerevisiae live cells (YST) (20, 40 and 60 mg/60 mL), and CB + YST (60 + 20, 60 + 40, 60 + 60 mg/60 mL) on mixed ruminal microorganism fermentation in vitro. Ruminal fluid was collected from a cow, mixed with phosphate buffer (1:2) and incubated (60 mL) anaerobically at 38°C for 24 h with or without supplement plus 400 mg (dry matter [DM] basis) substrate (hay plus concentrate, 1.5:1). The medium pH numerically decreased with CB and CB + YST, but was unchanged with YST. The total volatile fatty acid and proportion of propionate increased (P < 0.05) in all cases. The proportion of acetate decreased (P < 0.05) with CB and CB + YST, but increased (P < 0.05) with YST and that of butyrate increased (P < 0.05) with CB and CB + YST, but decreased (P < 0.05) with YST. Ammonia-N decreased (P < 0.05) with CB and CB + YST, but was unchanged with YST. The number of protozoa was unchanged, and that of cellulolytic bacteria increased (P < 0.05) in all cases. Total gas production increased (P < 0.05) in all cases. Methane decreased, hydrogen was unchanged by YST and both gases were unchanged by CB and CB + YST. The in vitro disappearance of DM and neutral detergent fiber increased (P < 0.05) by 11.2% and 8.9%, 9% and 8.5%, and 12.1% and 10.2% in the case of CB, YST and CB + YST, respectively. Therefore, the dietary supplementation of CB and/or YST may improve ruminal fermentation and digestibility.

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Section: Discussionmentioning

confidence: 99%

Increase of ruminal fiber digestion by cellobiose and a twin strain of Saccharomyces cerevisiae live cells in vitro

Lila

Mohammed

Takahashi

et al. 2006

Animal Science Journal

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“…A cellodextrin phosphorylase has been isolated only from C. therniocellum (Sheth and Alexander, 1969;Arai et al, 1994). Furthermore, cellobiose and cellodextrin phosphorylase activities have been detected in Fomrs unnosus (Hiittermann and Volger, 1973), several species of Cellulomonus (Schimz et al, 1983), and the ruminal bacteria Ruminococcus fluvefuciens (Ayers, 1958 ;Helaszek and White, 1991), Ruminococcus ulbus (Thurston et al, 1993), Fibrobacter sucrinogenes (Wells et al, 1995) and Prevotella ruminicolu (Lou et al, 1996). To date, however, no primary structures of cellobiose or cellodextrin phosphorylases are known.…”

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confidence: 99%

Purification and Properties of a Cellobiose Phosphorylase (CepA) and a Cellodextrin Phosphorylase (CepB) from the Cellulolytic Thermophile Clostridium Stercorarium

Reichenbecher

Lottspeich

Bronnenmeier

1997

European Journal of Biochemistry

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Two phosphorolytic enzymes displaying activity towards the soluble cellulose degradation products cellobiose and cellodextrins were purified from the crude extract of the cellulolytic thermophile Clostridium stercoruriurn. Both phosphorylases have monomeric structures with molecular masses of 93 and 91 kDa, respectively. Although the N-terminal amino acid sequences are highly similar, a clear distinction of the two enzymes could be made on the basis of their substrate specificities: the enzyme designated cellobiose phosphorylase cleaved exclusively the disaccharide substrate, whereas the enzyme designated cellodextrin phosphorylase accepted only oligosaccharides as substrates. Kinetic constants were determined for the cleavage of cellobiose and cellodextrins. Maximal activity was observed at 65°C in the pH range 6.0-7.0 for both enzymes. The sequences of the genes cepA and cepB encoding the cellobiose phosphorylase and the cellodextrin phosphorylase, respectively, have been submitted to the GenBank database.Keywords: phosphorylase ; cellobiose ; cellodextrin ; Clostridium; thermophilic.Enzymes capable of degrading cellobiose and cellodextrins are considered as essential components of microbial cellulolytic enzyme systems. They convert the cellobiose and cellodextrins formed during the enzymatic degradation of cellulose by the synergistic action of endoglucanases and exoglucanases to fermentable sugars. As cellulolytic enzymes are generally subject to product inhibition, an adequate level of cellobiose and cellodextrin removing enzymes is required for efficient breakdown of cellulose. The metabolism of soluble cellulose degradation products involves hydrolytic and phosphorolytic cleavage (Coughlan and Mayer, 1992). Hydrolysis is catalyzed by p-glucosidases releasing glucose from the disaccharide and the nonreducing ends of the oligosaccharides. Phosphorolysis is energetically advantageous and might constitute the primary route of cellobiose and cellodextrin utilization in particular in anaerobic environments. Cellobiose phosphorylase (cel1obiose:orthophosphate n-D-glUcoSyl-tranSferaSe) and cellodextrin phosphorylase

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“…In most cellulolytic microorgamsms examined, cellobiose is cleaved into glucose by cellobiase (13). However, in cellulolytic bacteria, which include Cellvibrio gilvus (34), Ruminococcusflavefaciens (5,6), and Clostridium thermocellum (2,31), cellobiose is converted into glucose 1-phosphate and glucose by cellobiose phosphorylase (EC 2.4.1.20). This enzyme is novel and results in conservation of the P-1,4…”

mentioning

confidence: 99%

Differential metabolism of cellobiose and glucose by Clostridium thermocellum and Clostridium thermohydrosulfuricum

Ng¹,

Zeikus²

1982

J Bacteriol

104

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Clostridium thermohydrosulfuricum consumed glucose in preference to cellobiose as an energy source for growth. The rates of substrate uptake in glucoseand cellobiose-grown cell suspensions were 45 and 24 nmol/min per mg (dry weight), respectively, at 65°C. The molar growth yields (i.e., grams of cells per mole of glucose equivalents) were similar on cellobiose and glucose (19 and 16, respectively). Both glucose-and cellobiose-grown cells contained a glucose permease activity and high levels of hexokinase (>0.34 ,umol/min per mg of protein at 40°C). Growth on cellobiose was associated with induction of a cellobiose permease activity. In contrast, Clostridium thermocellum metabolized cellobiose in preference to glucose as an energy source and displayed lower growth rates on both substrates. The substrate uptake rates in cellobioseand glucose-grown cell suspensions were 18 and 17 nmol/min per mg (dry weight), respectively. The molar yields were 38 on cellobiose and 20 on glucose. Extracts of glucoseand cellobiosegrown cells both contained cellobiose phosphorylase and phosphoglucomutase activities, whereas only glucose-grown cells contained detectable levels of glucose permease and hexokinase activities. The general catalytic and kinetic properties of the glucose-and cellobiose-catabolizing enzymes in the two species are described, and a model is proposed to distinguish differential saccharide metabolism by these thermophilic ethanologens.

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PHOSPHORYLATION OF CELLOBIOSE AND GLUCOSE BY RUMINOCOCCUS FLAVEFACIENS

Cited by 64 publications

References 5 publications

Increase of ruminal fiber digestion by cellobiose and a twin strain of Saccharomyces cerevisiae live cells in vitro

Increase of ruminal fiber digestion by cellobiose and a twin strain of Saccharomyces cerevisiae live cells in vitro

Purification and Properties of a Cellobiose Phosphorylase (CepA) and a Cellodextrin Phosphorylase (CepB) from the Cellulolytic Thermophile Clostridium Stercorarium

Differential metabolism of cellobiose and glucose by Clostridium thermocellum and Clostridium thermohydrosulfuricum

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