scholarly journals Ruminal and total plant cell-wall digestibility estimated by a combinedin situmethod utilizing mathematical models

1997 ◽  
Vol 78 (4) ◽  
pp. 583-598 ◽  
Author(s):  
Pekka Huhtanen ◽  
Aila Vanhatalo
Keyword(s):  
Cell Wall ◽  
Incubation Period ◽  
Plant Cell Wall ◽  
Intestinal Cell ◽  
Cell Wall Digestibility ◽  
Stages Of Growth ◽  
Cell Wall Digestion ◽  
Intestinal Digestion ◽  
Ruminal Digestion

Three ruminally and duodenally cannulated non-lactating Finnish Ayrshire cows were used to investigate ruminal and intestinal digestion of cell-wall carbohydrates by a combinedin situmethod. Five grasses cut at 10 d intervals were incubated in the rumen for 0, 6, 12, 24, 48, 72 and 96 h, and the undegraded residues were exposed to intestinal digestion. With advancing maturity of grass both the rate and extent of cell-wall digestion decreased. At early stages of growth the decreases were faster for the rate of digestion and at late stages of growth for the extent of digestion. Applying a passage rate of 0.02/h in one compartmental rumen model resulted in digestibility values markedly lower than typically observedin vivo.However, applying a rumen model incorporating a selective retention of particles and time-dependent release of particles from the non-escapable pool resulted in much higher digestibility values. Recovery of lignin after 96 h ruminal incubation with a subsequent mobile-bag incubation was very low (from 244 to 460 mg/g). Intestinal disappearance of neutral-detergent fibre (NDF) and hemicellulose decreased with advancing maturity of grass and with increasing length of preceding ruminal incubation period, i.e. with decreasing potential digestibility of the material. Disappearance of hemicellulose was much greater than that of cellulose for intact grasses but the difference diminished with increasing length of preceding rumen incubation period. On average, 195 mg/g of potentially digestible NDF disappeared from the mobile bags in the intestines. The post-ruminal digestion as a proportion of the total NDF digestibility varied between 0.034 and 0.058. Despite methodological problems both in ruminalin situand intestinal mobile bag techniques, these methods can be used to investigate ruminal and intestinal cell-wall digestion and to partition cell-wall digestibility between ruminal and post-ruminal digestion providing that appropriate rumen models are used.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

Endogenous Plant Cell Wall Digestion: A Key Mechanism in Insect Evolution

2012 ◽  
Vol 43 (1) ◽  
pp. 45-71 ◽  
Author(s):  
Nancy Calderón-Cortés ◽  
Mauricio Quesada ◽  
Hirofumi Watanabe ◽  
Horacio Cano-Camacho ◽  
Ken Oyama
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Insect Evolution ◽  
Cell Wall Digestion ◽  
Endogenous Plant

Neutron diffraction and proton nuclear magnetic resonance: complementary probes of in situ cellulose dimensions and primary plant cell wall structure

1993 ◽  
Vol 71 (10) ◽  
pp. 1375-1380 ◽  
Author(s):  
P. Martel ◽  
Iain E. P. Taylor
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Cell Wall ◽  
Magnetic Resonance ◽  
Neutron Diffraction ◽  
Potassium Hydroxide ◽  
Plant Cell Wall ◽  
Ammonium Oxalate ◽  
Proton Nuclear Magnetic Resonance ◽  
Scattering Measurements

Neutron diffraction was used to monitor the microscopic structure of cell walls from etiolated bean (Phaseolus vulgaris L.) hypocotyls after successive chemical fractionations with ammonium oxalate – oxalic acid and potassium hydroxide. Wide angle neutron scattering measurements showed that there was no highly ordered long range structure and confirm results from proton nuclear magnetic resonance techniques that there is alteration of the cell wall cellulose by chemical fractionations. Small angle scattering measurements showed that the residual cellulose microfibrils increased in diameter from 75.0 ± 2.3 to 110.0 ± 4.2 Å (1 Å = 0.1 nm) after successive treatments with ammonium oxalate – oxalic acid and potassium hydroxide. The technique has potential applications to study cellulose dimensions in situ. Key words: plant cell wall, cellulose dimensions, neutron diffraction, proton NMR.

scholarly journals Identification of bacteria involved in the decomposition of lignocellulosic biomass treated with cow rumen fluid by metagenomic analysis

2019 ◽  
Author(s):  
Chol Gyu Lee ◽  
Yasunori Baba ◽  
Ryoki Asano ◽  
Yasuhiro Fukuda ◽  
Chika Tada ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell Wall ◽  
Plant Biomass ◽  
Rumen Fluid ◽  
Waste Paper ◽  
Metagenomic Analysis ◽  
Fluid Systems ◽  
Genes Encoding ◽  
Identification Of Bacteria

AbstractPreviously, pretreatment of plant biomass using rumen fluid systems was developed to decompose cell wall. However, microbes which involved in plant cell wall decomposition in this system have not been identified, because the conditions of this system are different from the in situ rumen environment. We investigated the bacteria involved in the decomposition of cellulose and hemicellulose in a waste paper with the rumen pretreatment system using shotgun metagenomic analysis with next generation sequencing. After pretreatment of waste paper, about a half of the cellulose and hemicellulose content was decomposed. Genes encoding for cellulase and hemicellulase were mainly found to belonging to Ruminococcus, Clostridium, and Exiguobacterium. This study shows that Clostridium and Exiguobacterium, which have not been identified as predominant genus involved in cellulose and hemicellulose decomposition, might be categorized as the main fibrolytic bacteria in this system.

scholarly journals Improvement in Saccharification Yield of Mixed Rumen Enzymes by Identification of Recalcitrant Cell Wall Constituents Using Enzyme Fingerprinting

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Ajay Badhan ◽  
Yu-Xi Wang ◽  
Robert Gruninger ◽  
Donald Patton ◽  
Justin Powlowski ◽  
...  
Keyword(s):  
Cell Wall ◽  
Experimental Design ◽  
Plant Cell Wall ◽  
Structural Information ◽  
Barley Straw ◽  
Statistical Experimental Design ◽  
Enzyme Pretreatment ◽  
Barley Silage ◽  
Ruminal Digestion

Identification of recalcitrant factors that limit digestion of forages and the development of enzymatic approaches that improve hydrolysis could play a key role in improving the efficiency of meat and milk production in ruminants. Enzyme fingerprinting of barley silage fed to heifers and total tract indigestible fibre residue (TIFR) collected from feces was used to identify cell wall components resistant to total tract digestion. Enzyme fingerprinting results identified acetyl xylan esterases as key to the enhanced ruminal digestion. FTIR analysis also suggested cross-link cell wall polymers as principal components of indigested fiber residues in feces. Based on structural information from enzymatic fingerprinting and FTIR, enzyme pretreatment to enhance glucose yield from barley straw and alfalfa hay upon exposure to mixed rumen-enzymes was developed. Prehydrolysis effects of recombinant fungal fibrolytic hydrolases were analyzed using microassay in combination with statistical experimental design. Recombinant hemicellulases and auxiliary enzymes initiated degradation of plant structural polysaccharides upon application and improved thein vitrosaccharification of alfalfa and barley straw by mixed rumen enzymes. The validation results showed that microassay in combination with statistical experimental design can be successfully used to predict effective enzyme pretreatments that can enhance plant cell wall digestion by mixed rumen enzymes.

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