Endo-1, 4-β-glucanase and β-glucosidase of the ciliate Polyplastron multivesiculatum free of cellulolytic bacteria

1986 ◽  
Vol 32 (3) ◽  
pp. 219-225 ◽  
Author(s):  
A. Bonhomme ◽  
G. Fonty ◽  
M. J. Foglietti ◽  
D. Robic ◽  
M. Weber

To determine the contribution of protozoal activity to cellulose degradation, we maintained the ciliate Polyplastron multivesiculatum free of extracellular and intracellular cellulolytic bacteria. Control experiments to verify the absence of such bacteria were performed on cellular extracts, on filtrates, and on ciliates before lyophilization. The enzymatic activity was determined by viscometry and by determining the amount of reducing sugars produced. The enzyme was found to be an endo-1, 4- β-glucanase. Polyplastron multivesiculatum which was maintained free of extracellular and intracellular bacteria degraded soluble derivatives of cellulose and slightly degraded native cellulose. The activity was not due to intracellular bacterial cellulase, as ingested bacteria were lysed and digested by proteolytic enzymes of the protozoan. In addition, when preparing the filtrate solutions, P. multivesiculatum was maintained in culture for 5 days with Streptococcus faecalis (a facultatively anaerobic, noncellulolytic bacterium). Isoelectric focusing and chromatofocusing of lyophilized P. multivesiculatum that was free of cellulolytic bacteria yielded three protein fractions that degrade carboxymethylcellulose and hydroxyethylcellulose. Chromatofocusing also revealed the presence of two protein fractions with β-glucosidase activity.

2019 ◽  
Vol 7 (2) ◽  
pp. 190
Author(s):  
Monalisa Nababan ◽  
Ida Bagus Wayan Gunam ◽  
I Made Mahaputra Wijaya

The purpose of this research was to elucidate the potentials of cellulolytic bacteria isolates in producing crude cellulose enzymes and to determine the ability of exoglucanase enzymes and endoglucanase enzymes produced from selected cellulolytic bacteria isolates. Ten potential isolates from previous research were confirmed using 1% Carboxymethyl Cellulose (CMC) media with the addition of Congo red and four potential isolates were obtained which then crude cellulose production and enzyme activity tests were carried out using cellulose substrates such as Carboxymethyl Cellulose (CMC), and Filter Paper (FP) Whattman number 1. The exoglucanase enzyme activity was obtained between 0.069 IU/mL to 0.072 IU/mL. The activity test of endoglucanase enzyme was obtained between 0.069 IU / mL to 0.074 IU/mL. Cellulose degradation was obtained between 3.32% to 11.37%. Isolate that have the highest enzymatic activity and cellulose degradation ability was B2S8. Keywords: Cellulolytic bacteria, Cellulase enzyme, Enzyme activity, Congo red.  


1977 ◽  
Vol 38 (02) ◽  
pp. 0475-0485 ◽  
Author(s):  
Anna D. Borsodi ◽  
Ralph A. Bradshaw

SummaryThe plasma of individuals, hetero- or homozygous for α1-antitrypsin deficiency, contains greatly decreased amounts of antithrombin activity as assayed against factor Xa. However, heparin stimulation of the residual antithrombin activity is observed, which is comparable to that of normal plasma. Antithrombins isolated from both normal and α1-antitrypsin deficient plasma by a simplified procedure are indistinguishable in both properties and yields. The microheterogeneity observed on isoelectric focusing of both preparations can be eliminated by treatment with neuraminidase. Neither purified human antithrombin nor α1-antitrypsin, when assayed against bovine trypsin, is stimulated by heparin. These results clearly establish the unique natures of antithrombin and α1-antitrypsin and show that about 75% of the antithrombin activity measured in normal plasma is due to α1-antitrypsin. Estimates of anti thrombin III activity in normal plasma by assays dependent on enzymatic activity can probably be obtained only in the presence of heparin.


1990 ◽  
Vol 111 (4) ◽  
pp. 1639-1643 ◽  
Author(s):  
S C Ho ◽  
M Schindler ◽  
J L Wang

Extracts of Bradyrhizobium japonicum were fractionated on Sepharose columns covalently derivatized with lactose. Elution of the material that was specifically bound to the affinity column with lactose yielded a protein of Mr approximately 38,000. Isoelectric focusing of this sample yielded two spots with pI values of 6.4 and 6.8. This protein specifically bound to galactose-containing glycoconjugates, but did not bind either to glucose or mannose. Derivatives of galactose at the C-2 position showed much weaker binding; there was an 18-fold difference in the relative binding affinities of galactose versus N-acetyl-D-galactosamine. These results indicate that we have purified a newly identified carbohydrate-binding protein from Bradyrhizobium japonicum, that can exquisitely distinguish galactose from its derivatives at the C-2 position.


1937 ◽  
Vol 65 (6) ◽  
pp. 873-883 ◽  
Author(s):  
René J. Dubos

1. Living pneumococcus cells contain a group of enzymes, the bacteriolytic system, capable of causing the lysis of heat-killed pneumococci (R and S variants irrespective of type derivation). This lysis expresses itself by a loss of the Gram staining reaction, a disintegration of the cell body, and a clearing of the bacterial suspension. 2. Under certain conditions of treatment with the bacteriolytic complex, it is possible to render the cocci Gram-negative without changing their characteristic morphology, or causing any appreciable clearing of the cell suspension. 3. The enzyme responsible for this change has been partially purified, and some of its properties described. 4. The cellular structure which is responsible for the Gram-positive reaction of pneumococci is resistant to proteolytic enzymes, and is still present when tryptic digestion has reduced the heat-killed cell to a body which has lost 75 per cent of its original weight, and contains only 8 per cent nitrogen. 5. The same enzyme preparation which attacks pneumococci is also capable of liberating reducing sugars from some acetyl amino glucose glucuronides of animal and bacterial origin. The possibility is considered, and discussed, that one and the same enzyme in the autolytic complex is capable of attacking both types of substrates.


1969 ◽  
Vol 22 (5) ◽  
pp. 1197 ◽  
Author(s):  
RL Darskus ◽  
JM Gillespie ◽  
H Lindley

S-Carboxymethyl derivatives of the high-sulphur components of reduced Merino wool have been subdivided by chromatography into 17 fractions, the amino acid compositions of which are reported. Tryptic, chymotryptic, and thermolysin digests of each fraction have been studied by high-voltage paper electrophoresis at pH 3�5 and 6�5. The results suggest that the high-sulphur proteins consist of families of proteins probably containing common structural features. Evidence is presented that the heterogeneity of high-sulphur proteins is not artefactual.


Blood ◽  
1980 ◽  
Vol 56 (3) ◽  
pp. 571-572 ◽  
Author(s):  
C Tegos ◽  
E Beutler

Abstract Partially purified hemoglobin A2 has been examined for the existence of glycosylated components by isoelectric focusing and by acid agar gel electrophoresis. Bands analogous to the glycohemoglobin derivatives of hemoglobin A, hemoglobin-A1.a.b.c, were readily detected. Evidence that these minor bands are in fact glycohemoglobins was obtained by showing that 14C-glucose bound to hemoglobin A2 moved with these minor bands. The amounts of glycohemoglobin derivatives of hemoglobin A2 were increased in the blood of diabetic patients.


1967 ◽  
Vol 45 (3) ◽  
pp. 275-290 ◽  
Author(s):  
S. C. Williams ◽  
J. K. N. Jones

A study has been made of various methods available for the identification and separation of the methyl ethers of arabinose. Gas–liquid partition chromatography has been used to separate the acetylated glycosides and the acetylated alditols of the methyl ethers of arabinose. All of the methyl ethers of arabinopyranose and arabinofuranose have been separated by paper chromatography. Several spray reagents have been used to distinguish between those methyl ethers with similar rates of movement. Thin-layer chromatography has been used to separate the methyl glycosides, acetylated methyl glycosides, and glycitols of the methyl ethers of arabinose, as well as the methyl ethers of the reducing sugar. The optical rotations of the reducing sugars and of the methyl glycosides of the methyl ethers of arabinose provide information about the ring form and, in the case of the glycosides, about the anomer present. The rotations of the acetylated and unacetylated O-methyl arabinitols aid in the determination of the position of the methyl substitutents. In connection with this study, all of the mono-O-methyl and tri-O-methyl, and most of the di-O-methyl ethers of arabinose have been synthesized. New syntheses have been devised for 4-O-methyl and 2,3-di-O-methyl arabinose, and the other sugars have been synthesized by known or partially revised syntheses. During this work, previously unreported derivatives of these sugars have been prepared.


1982 ◽  
Vol 203 (2) ◽  
pp. 427-433 ◽  
Author(s):  
N UI ◽  
C Takasaki ◽  
N Tamiya

The isoelectric points of erabutoxins a, b and c, neurotoxic proteins of a sea snake, Laticauda semifasciata, were determined by density-gradient isoelectric focusing. The same measurement was also made with monoacyl derivatives of erabutoxin b, in which each one of all amino groups had been either acetylated or propionylated. Erabutoxins a and b showed the same isoelectric point at pH 9.68. The values for [1-N alpha-acetyl-arginine]-, [15-N6-acetyl-lysine]-, [27-N6-acetyl-lysine]-, [47-N6-propionyl-lysine]- and [51-N6-acetyl-lysine]-erabutoxin b were at pH 9.52, 9.31, 9.45, 9.22 and 9.09 respectively, being definitely different from each other and lower than the value for the unmodified molecule. The isoelectric point of erabutoxin c, which is [51-asparagine]-erabutoxin b, was the same as that of [51-N6-acetyl-lysine]erabutoxin b. Assuming that no change in pK occurs on monoacylation, the pK values of amino groups in erabutoxin b were calculated from the isoelectric-point data. It is indicated that the pK values of zeta-amino groups differ markedly from each other and that the value of alpha-amino group is anomalously high.


1994 ◽  
Vol 40 (2) ◽  
pp. 106-112 ◽  
Author(s):  
Thomas Krarup ◽  
Lauritz W. Olson ◽  
Hans Peter Heldt-Hansen

The extracellular proteolytic enzymes of eight saprophytic, eucarpic, and monocentric isolates from two genera of the order Spizellomycetales and from one genus of the order Chytridiales (Chytridiomycetes) have been partially characterized. The isolectric points of the proteases were estimated from zymograms and demonstrate the existence of three types of proteolytic activity in most isolates. The proteases were tested against synthetic chromogenic peptide substrates and a selection of cations and more complex compounds, and the results suggest that parts of the extracellular proteolytic activities are due to proteases from two groups: the Ca2+ stabilized proteases and the alkaline serine proteases.Key words: serine proteases, metalloproteases, Chytridiomycetes, isoelectric focusing, chromogenic peptide substrates.


2001 ◽  
Vol 67 (9) ◽  
pp. 3846-3851 ◽  
Author(s):  
Mickaël Desvaux ◽  
Henri Petitdemange

ABSTRACT An investigation of cellulose degradation by the nonruminal, cellulolytic, mesophilic bacterium Clostridium cellulolyticum was performed in cellulose-fed chemostat cultures with ammonium as the growth-limiting nutrient. At any dilution rate (D), acetate was always the main product of the catabolism, with a yield of product from substrate ranging between 37.7 and 51.5 g per mol of hexose equivalent fermented and an acetate/ethanol ratio always higher than 1. AsD rose, the acetyl coenzyme A was rerouted in favor of ethanol pathways, and ethanol production could represent up to 17.7% of the carbon consumed. Lactate was significantly produced, but with increasing D, the specific lactate production rate declined, as did the specific rate of production of extracellular pyruvate. The proportion of the original carbon directed towards phosphoglucomutase remained constant, and the carbon surplus was balanced mainly by exopolysaccharide and glycogen biosyntheses at highD values, while cellodextrin excretion occurred mainly at lower ones. With increasing D, the specific rate of carbon flowing down catabolites increased as well, but when expressed as a percentage of carbon it declined, while the percentage of carbon directed through biosynthesis pathways was enhanced. The maximum growth and energetic yields were lower than those obtained in cellulose-limited chemostats and were related to an uncoupling between catabolism and anabolism leading to an excess of energy. Compared to growth on cellobiose in ammonium-limited chemostats (E. Guedon, M. Desvaux, and H. Petitdemange, J. Bacteriol. 182:2010–2017, 2000), (i) a specific consumption rate of carbon of as high as 26.72 mmol of hexose equivalent g of cells−1h−1 could not be reached and (ii) the proportions of carbon directed towards cellodextrin, glycogen, and exopolysaccharide pathways were not as high as first determined on cellobiose. While the use of cellobiose allows highlighting of metabolic limitation and regulation of C. cellulolyticumunder ammonium-limited conditions, some of these events should then rather be interpreted as distortions of the metabolism. Growth of cellulolytic bacteria on easily available carbon and nitrogen sources represents conditions far different from those of the natural lignocellulosic compounds.


Sign in / Sign up

Export Citation Format

Share Document