Xylanase‐Mediated Hydrolysis of Wheat Bran: Evidence for Subcellular Heterogeneity of Cell Walls

2004 ◽  
Vol 165 (4) ◽  
pp. 553-563 ◽  
Author(s):  
Johnny Beaugrand ◽  
Danièle Reis ◽  
Fabienne Guillon ◽  
Philippe Debeire ◽  
Brigitte Chabbert
Keyword(s):  
1998 ◽  
Vol 26 (2) ◽  
pp. S168-S168 ◽  
Author(s):  
Maria T. Garcia-Conesa ◽  
Paul A. Kroon ◽  
Gary Williamson

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Shiyi Ou ◽  
Jing Zhang ◽  
Yong Wang ◽  
Ning Zhang

A mixture of wheat bran with maize bran as a carbon source and addition of (NH4)SO4 as nitrogen source was found to significantly increase production of feruloyl esterase (FAE) enzyme compared with wheat bran as a sole carbon and nitrogen source. The optimal conditions in conical flasks were carbon source (30 g) to water 1 : 1, maize bran to wheat bran 1 : 2, (NH4)SO4 1.2 g and MgSO4 70 mg. Under these conditions, FAE activity was 7.68 mU/g. The FAE activity on the mixed carbon sources showed, high activity against the plant cell walls contained in the cultures.


2000 ◽  
Vol 182 (20) ◽  
pp. 5676-5682 ◽  
Author(s):  
Shengde Zhou ◽  
Lonnie O. Ingram

ABSTRACT Erwinia chrysanthemi produces a battery of hydrolases and lyases which are very effective in the maceration of plant cell walls. Although two endoglucanases (CelZ and CelY; formerly EGZ and EGY) are produced, CelZ represents approximately 95% of the total carboxymethyl cellulase activity. In this study, we have examined the effectiveness of CelY and CelZ alone and of combinations of both enzymes using carboxymethyl cellulose (CMC) and amorphous cellulose (acid-swollen cellulose) as substrates. Synergy was observed with both substrates. Maximal synergy (1.8-fold) was observed for combinations containing primarily CelZ; the ratio of enzyme activities produced was similar to those produced by cultures of E. chrysanthemi. CelY and CelZ were quite different in substrate preference. CelY was unable to hydrolyze soluble cellooligosaccharides (cellotetraose and cellopentaose) but hydrolyzed CMC to fragments averaging 10.7 glucosyl units. In contrast, CelZ readily hydrolyzed cellotetraose, cellopentaose, and amorphous cellulose to produce cellobiose and cellotriose as dominant products. CelZ hydrolyzed CMC to fragments averaging 3.6 glucosyl units. In combination, CelZ and CelY hydrolyzed CMC to products averaging 2.3 glucosyl units. Synergy did not require the simultaneous presence of both enzymes. Enzymatic modification of the substrate by CelY increased the rate and extent of hydrolysis by CelZ. Full synergy was retained by the sequential hydrolysis of CMC, provided CelY was used as the first enzyme. A general mechanism is proposed to explain the synergy between these two enzymes based primarily on differences in substrate preference.


Author(s):  
Bryan A. White ◽  
Roderick I. Mackie ◽  
Kinchel C. Doerner

1967 ◽  
Vol 22 (10) ◽  
pp. 1062-1067 ◽  
Author(s):  
Roland Plapp ◽  
Otto Kandler

The amino acid sequence of the peptide moiety of the mureins of Lactobacillus coryniformis and Lactobacillus cellobiosus cell walls was determined. This was accomplished by the identification of peptides obtained after partial hydrolysis of purified cell walls and by the identification of UDP-activated murein precursors accumulated by ᴅ-cycloserine inhibition. The amino acid sequence proved to be : ʟ-ala-ᴅ-glu-ʟ-lys-ᴅ-ala for L. coryniformis and L-ala-D-glu-L-orn-D-ala for L. cellobio-.D-asp D-aspsus. Aspartic acid is involved in the cross-linking of the mureins by forming a peptide bond with the C-terminal D-alanine of an adjacent muropeptide. Glutamic acid as well as aspartic acid are present as amides.


1981 ◽  
Vol 27 (12) ◽  
pp. 1334-1340 ◽  
Author(s):  
S. N. Sinha ◽  
B. L. Ghosh ◽  
S. N. Ghose

The presence of a cellulase inhibitor in the wheat bran culture of a fungus is reported for the first time. The inhibitor has a low molecular weight and is relatively stable to heat. It is absent from wheat bran and is not produced in a chemically defined medium. Unlike cellulase inhibitors of plant origin, this inhibitor is not a polyphenol. It inhibits the hydrolysis of cotton to a greater degree than that of filter paper or carboxymethylcellulose. In addition to inhibiting Aspergillus terreus cellulase, it also inhibits a variety of commercial cellulases.


1982 ◽  
Vol 28 (12) ◽  
pp. 1289-1295 ◽  
Author(s):  
M. I. Perez-Leblic ◽  
Fuensanta Reyes ◽  
R. Lahoz ◽  
S. A. Archer

Cultures of Penicillium oxalicum growing on a denned medium supplemented with yeast extract reached the onset of autolysis after 3 days at 25 °C. Thenceforth, autolysis was progressive and eventual reductions in dry weight of 96% were recorded by day 47. The pH of the medium fluctuated between 4.0 during the exponential phase of growth and 9.0 during autolysis. Electron microscopy of autolyzing cultures revealed a progressive loss of cytoplasmic ultrastructure. Digestion of the cell walls, with a rapid hydrolysis of the three external layers and a low hydrolysis of the two inner layers, was accompanied by deep pitting and by loss of the distinct five-layered structure. A lytic enzyme complex was obtained from the filtrates of extensively autolyzed cultures. It was rich in (1 → 3)-β-glucanase and other enzymes active against a range of fungal cell wall and storage polysaccharides. This enzyme complex degraded extensively isolated cell walls of P. oxalicum and three other Ascomycetes but had less effect on walls isolated from Mucor mucedo or Schizophyllum commune. In the case of P. oxalicum, cell walls harvested from young cultures were more readily digested than were the walls from older cultures.


1957 ◽  
Vol 35 (2) ◽  
pp. 108-114 ◽  
Author(s):  
J. Schmorak ◽  
C. T. Bishop ◽  
G. A. Adams

Graded acid hydrolysis of a soluble wheat bran hemicellulose containing L-arabinose (50%), D-xylose (38.5%), and D-glucuronic acid (9.0%) preferentially removed the L-arabinose giving an insoluble acidic polysaccharide in approximately 25% yield by weight. Methylation studies, periodate oxidation data, and hypoiodite end group estimations showed that the degraded polysaccharide was composed of repeating units of 7-8 D-xylopyranose residues joined by β,1 → 4 linkages. To this repeating unit, one D-glucuronic acid unit was attached by a 1 → 2 glycosidic bond. The cellulolytic enzyme of Myrotheciumverrucaria, which is specific for β,1 → 4 glycosidic linkages, hydrolyzed the degraded polysaccharide although it had no effect on the parent hemicellulose


2018 ◽  
Vol 12 (2) ◽  
Author(s):  
A. Kapustian ◽  
N. Cherno ◽  
О. Nikulina

The possibility of obtaining bioavailable mixed ligand chelate complexes of calcium has been considered. As bioligands, it is proposed to use the metabolic products of probiotic bacteria combination and products of enzymatic hydrolysis of peptidoglycans of their cell walls. The culture fluid of probiotic bacteria composition has been investigated for the determination of metabolites in its composition that can participate in the formation of calcium chelate complexes. The qualitative composition and quantitative content of organic acids of a culture fluid have been determined. It has been established that it contains the following acids: oxalic (1.6 mg/dm3), citric (22.1 mg/dm3), acetic (575.8 mg/dm3), lactic (236.3 mg/dm3), benzoic (1.5 mg/dm3). In addition, it has been found that in the composition of the culture liquid, free amino acids and soluble protein are also present in the amount of 1.2 mg/cm3 and 5 mg/cm3, respectively.In order to obtain fragments of peptidoglycans of cell walls of probiotic bacteria as potential bioligands for complex formation, their enzymatic hydrolysis with pancreatin has been performed. It has been established that the highest content of biologically active muropeptides is 5.1 mg/cm3 and it is accumulated during hydrolysis of the substrate for 180 minutes, the ratio of enzyme: substrate 1: 100 and 5.1 mg/cm3.By methods of nephelometry and spectrophotometry, it has been established that the obtained mixed ligand systems are effective chelating agents and, depending on the composition, bind calcium in amounts of 9, 14 and 16 mg/cm3. Identification of the pH stability of the complex has been shown that in the range of pH values 4–7, the chelate system is stable, at pH 2 only 10% of the complex is stored, at pH 9 60% is preserved. By method of differential scanning calorimetry the thermostability of the complex has been investigated. It has been established that the complex is stable in the temperature range of 20–122°С, and therefore can be used in the composition of health foods, the technology of which involves high-temperature processing.


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