Hydrolysis of the cell-wall carbohydrates of grasses by carbohydrases in relation to voluntary intake by sheep

SUMMARYThe relationship between the voluntary dry-matter intake of grasses and their in vitro digestibility (DOMD), chemical composition and susceptibility to enzymic hydrolysis was examined in two experiments. The grasses were artificially dried and represented a range of species and varieties cut at various growth stages.In both experiments some 70% of the observed variation in intake could be attributed to differences in in vitro digestibility between the grasses and between the growth stages when harvested. Estimations of acid detergent fibre, pepsin solubility and cellulose generally accounted for less than 70% of the variation in intake.The enzyme digestion techniques, on the other hand, accounted for up to 79% of the variation. The content of enzymically unhydrolysable cell wall gave the highest correlation with voluntary intake (r = −0·88 and −0·89, residual standard deviation 5·5 and 6·2, for the two experiments).It is concluded that simplified techniques based on cellulase digestion of plant material may be advantageously applied to breeding programmes with the expectation of identifying material high in digestibility and with good intake characteristics.

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Cell Wall Carbohydrates of Flaccidgrass Plant Parts. II. Neutral Sugar Relationships to In Vitro Disappearance and Fiber Fractions 1

Crop Science ◽

10.2135/cropsci1987.0011183x002700050048x ◽

1987 ◽

Vol 27 (5) ◽

pp. 1063-1068 ◽

Cited By ~ 4

Author(s):

J. M. Ruiter ◽

J. C. Burns

Keyword(s):

Cell Wall ◽

Neutral Sugar ◽

Plant Parts ◽

Fiber Fractions ◽

Cell Wall Carbohydrates

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The use of cell wall organic matter components and in vitro degradability characteristics to predict intake and digestibility of white clover for sheep

Australian Journal of Agricultural Research ◽

10.1071/ar9951111 ◽

1995 ◽

Vol 46 (6) ◽

pp. 1111 ◽

Cited By ~ 2

Author(s):

KS Nandra ◽

VH Oddy ◽

JF Ayres ◽

PJ Nicholls ◽

B Langevad ◽

...

Keyword(s):

Cell Wall ◽

Organic Matter ◽

White Clover ◽

Good Precision ◽

Digestible Organic Matter ◽

Predictive Relations ◽

Voluntary Intake ◽

Organic Matter Digestibility

The relations of the laboratory measurement of cell wall organic matter (CWOM) components and of the in vitro degradability characteristics of CWOM with in vivo digestibility and voluntary intake for high quality white clover were investigated. The voluntary intake, apparent digestibility and apparent rumen retention time of CWOM of white clover harvested at various stages of maturity were measured in rumen-cannulated Merino wether sheep. The in vitro degradability characteristics of CWOM of these diets were also measured. This study has quantified strong predictive relations between structural fibre constituents or degradation parameters and both digestibility and intake for white clover. The CWOM, cellulose and hemicellulose contents and potential degradability of CWOM of the white clover predicted in vivo organic matter digestibility with good precision (r2 = 0.74, 0.67, 0.72 and 0.72 respectively). The voluntary intakes of organic matter and digestible organic matter of the white clover were strongly related to CWOM, cellulose and hemicellulose contents and to the rate of degradation of CWOM in the rumen and the fits of these relations were at least as good as those predicting organic matter digestibility. The predictive equations based on CWOM: OMD (g/kg) = 97.6-0.081 (� 0.012) CWOM OMI (g/kg) = 83-0.085 (� 0.018) CWOM DOMI (g/kg) = 71.4-0.098 (� 0.015) CWOM are recommended because of the ease of analysis of CWOM in the laboratory.

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Waterlogging tolerance in pigeonpea (Cajanus cajan (L.) Millsp.): genotypic variability and identification of tolerant genotypes

The Journal of Agricultural Science ◽

10.1017/s0021859612000755 ◽

2012 ◽

Vol 151 (5) ◽

pp. 659-671 ◽

Cited By ~ 12

Author(s):

R. SULTANA ◽

M. I. VALES ◽

K. B. SAXENA ◽

A. RATHORE ◽

S. RAO ◽

...

Keyword(s):

Phenotypic Variation ◽

Survival Rates ◽

Growth Stages ◽

Waterlogging Tolerance ◽

Breeding Lines ◽

Legume Crop ◽

Breeding Programmes ◽

Early Seedling ◽

Elite Breeding Lines

SUMMARYPigeonpea is an important legume crop of the semi-arid tropics. In India, pigeonpea is mostly grown in areas prone to waterlogging, resulting in major production losses. It is imperative to identify genotypes that show tolerance at critical crop growth stages to prevent these losses. A selection of 272 diverse pigeonpea accessions was evaluated for seed submergence tolerance for different durations (0, 120, 144, 168 and 192 h) under in vitro conditions in the laboratory. All genotypes exhibited high (0·79–0·98) survival rates for up to 120 h of submergence. After 192 h of submergence, the hybrids as a group exhibited significantly higher survival rates (0·79) than the germplasm (0·71), elite breeding lines (0·68) and commercial varieties (0·58). Ninety-six genotypes representing the phenotypic variation observed during laboratory screening were further evaluated for waterlogging tolerance at the early seedling stage using pots, and survival rates were recorded for 8 days after completion of the stress treatment. Forty-nine of these 96 genotypes, representing the phenotypic variation for waterlogging tolerance, were chosen in order to evaluate their performance under natural field conditions. The following cultivated varieties and hybrids were identified as tolerant after three levels of testing (in vitro, in pots and in the field): ICPH 2431, ICPH 2740, ICPH 2671, ICPH 4187, MAL 9, LRG 30, Maruti, ICPL 20128, ICPL 332, ICPL 20237, ICPL 20238, Asha and MAL 15. These materials can be used as sources of waterlogging tolerance in breeding programmes.

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Isolation of anatomically defined cell walls from fodder kale, and their contributions to determining the in vitro cellulase digestibility of the whole plant

The Journal of Agricultural Science ◽

10.1017/s0021859600047304 ◽

1984 ◽

Vol 103 (2) ◽

pp. 347-352 ◽

Cited By ~ 11

Author(s):

J. G. McCluskey ◽

M. J. Allison ◽

H. J. Duncan ◽

M. C. Jarvis

Keyword(s):

Cell Wall ◽

Cell Walls ◽

Stem Anatomy ◽

Vascular Cell ◽

Cellulase Digestion ◽

Whole Plant ◽

Digestible Organic Matter ◽

Component Cell ◽

Whole Plants

SUMMARYVascular and non-vascular cell walls were isolated separately from leaves, upper stems and lower stems of 12 kale (Brassica oleracea L.) cultivars, by a sieving technique. The digestible organic matter in the dry matter (DOMD) of the cell walls and of the whole plants was determined by pepsin-cellulase digestion. The measured whole-plant DOMD correlated closely with the DOMD predicted by adding together the amounts of non-digested material derived from all the plant's component cell-wall fractions. Differences in DOMD between cultivars were determined primarily by the amount of vascular cell walls in the stems, particularly the lower stems; that is, by the stem anatomy. The vascular cell walls of the upper stems had a wider range of DOMD values and a higher mean DOMD than the vascular cell walls of the lower stems. Thus cell-wall composition made some contribution to determining the whole-plant DOMD, although it contributed less than the anatomy of the stem.

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Characterization of the Bifunctional Glycosyltransferase/Acyltransferase Penicillin-Binding Protein 4 of Listeria monocytogenes

Journal of Bacteriology ◽

10.1128/jb.188.5.1875-1881.2006 ◽

2006 ◽

Vol 188 (5) ◽

pp. 1875-1881 ◽

Cited By ~ 27

Author(s):

Joanna Zawadzka-Skomiał ◽

Zdzislaw Markiewicz ◽

Martine Nguyen-Distèche ◽

Bart Devreese ◽

Jean-Marie Frère ◽

...

Keyword(s):

Cell Wall ◽

Listeria Monocytogenes ◽

Chain Elongation ◽

Lipid Ii ◽

Food Borne ◽

Glycan Chain ◽

Chain Polymerization ◽

Hydrolysis Of

ABSTRACT Multimodular penicillin-binding proteins (PBPs) are essential enzymes responsible for bacterial cell wall peptidoglycan (PG) assembly. Their glycosyltransferase activity catalyzes glycan chain elongation from lipid II substrate (undecaprenyl-pyrophosphoryl-N-acetylglucosamine-N-acetylmuramic acid-pentapeptide), and their transpeptidase activity catalyzes cross-linking between peptides carried by two adjacent glycan chains. Listeria monocytogenes is a food-borne pathogen which exerts its virulence through secreted and cell wall PG-associated virulence factors. This bacterium has five PBPs, including two bifunctional glycosyltransferase/transpeptidase class A PBPs, namely, PBP1 and PBP4. We have expressed and purified the latter and have shown that it binds penicillin and catalyzes in vitro glycan chain polymerization with an efficiency of 1,400 M−1 s−1 from Escherichia coli lipid II substrate. PBP4 also catalyzes the aminolysis (d-Ala as acceptor) and hydrolysis of the thiolester donor substrate benzoyl-Gly-thioglycolate, indicating that PBP4 possesses both transpeptidase and carboxypeptidase activities. Disruption of the gene lmo2229 encoding PBP4 in L. monocytogenes EGD did not have any significant effect on growth rate, peptidoglycan composition, cell morphology, or sensitivity to β-lactam antibiotics but did increase the resistance of the mutant to moenomycin.

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Nutritive evaluation of two strains of mature subterranean clover

Australian Journal of Experimental Agriculture ◽

10.1071/ea9680295 ◽

1968 ◽

Vol 8 (32) ◽

pp. 295 ◽

Cited By ~ 1

Author(s):

ID Hume ◽

M Somers ◽

NR McKeown

Keyword(s):

Dry Matter ◽

Nutritive Value ◽

Biological Significance ◽

Subterranean Clover ◽

In Vitro Digestibility ◽

Voluntary Intake ◽

Main Component ◽

The Relationship

The relationship between the in vivo and in vitro digestibility of leguminous herbage was examined. Further studies were made using in vivo-in vitro digestibility estimations to compare the nutritive value to sheep of two strains (Yarloop and Woogenellup) of subterranean clover. The digestibilities of the main component parts (viz. stem, petiole, leaf, and burr) of the plants of each strain were also estimated in vitro. Digestibility differences between strains and between parts were examined on the basis of the chemical composition of their dry matter. Woogenellup was significantly more digestible than Yarloop, both in vivo and in vitro. Voluntary intake of Woogenellup was also significantly greater than that of Yarloop. The in vitro digestibility of stem did not differ significantly from that of petiole. Nor did the digestibility of leaf differ significantly from that of burr. However, the digestibility of stem and petiole together was greater than that of leaf and burr together. These findings are discussed in relation to their possible biological significance.

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THE BIOSYNTHESIS OF CELL WALL CARBOHYDRATES: GLUCOSE-C14 AS A CELLULOSE PRECURSOR IN WHEAT PLANTS

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o54-019 ◽

1954 ◽

Vol 32 (3) ◽

pp. 170-177 ◽

Cited By ~ 12

Author(s):

Stewart A. Brown ◽

A. C. Neish

Keyword(s):

Cell Wall ◽

Succinic Acid ◽

Skeletal Rearrangement ◽

Carbon 14 ◽

Cell Wall Carbohydrates ◽

Hydrolysis Of

The formation of cellulose in wheat plants has been studied using as precursors glucose-1-C14, sorbitol-1-C14, and succinic acid-2,3-C14, which were administered to the plant aseptically by injection of sterile solutions into the hollow internodes. Glucose obtained by hydrolysis of the cellulose, isolated after the plants had grown for 24 to 48 hr. following the injection of labelled glucose, showed a concentration of at least 50% of the total C14 in carbon-1. When sorbitol was injected most of the carbon-14 was fairly evenly divided between C-1 and C-6, and when succinic acid was used evidence of a comparatively uniform labelling of the glucose was obtained. The results indicate that there is considerable conversion of glucose to cellulose without skeletal rearrangement, and that there is also appreciable cellulose formation from resynthesized glucose. Sorbitol is not an intermediate between glucose and cellulose; it is suggested that it is converted to glucose largely by way of three-carbon fragments.

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EFFECT OF FERMENTATION TIME IN THE ARTIFICIAL RUMEN ON THE RELATIONSHIP OF IN VITRO DIGESTIBILITY TO DIGESTIBILTY AND INTAKE OF HAY BY SHEEP

Canadian Journal of Animal Science ◽

10.4141/cjas68-048 ◽

1968 ◽

Vol 48 (3) ◽

pp. 361-372 ◽

Cited By ~ 5

Author(s):

J. E. Troelsen ◽

J. M. Bell

Keyword(s):

In Vitro Digestion ◽

In Vitro Digestibility ◽

Growth Stages ◽

Fermentation Time ◽

Assay Procedure ◽

Relationship Of ◽

Physical And Chemical ◽

The Relationship

The digestibility and intake of several kinds of hay at several growth stages were measured with sheep. The in vitro digestibility was determined by a two-stage procedure. Because the in vitro digestibility of dry matter was unduly affected by a high solubility of the ash fraction, organic matter digestibility was the preferred criterion. In vitro digestibility was measured after fermentation times of 6, 12, 24, 48 or 96 hr. Significant correlations (P < 0.001) were found between in vivo and in vitro digestibility at each of these times. Near-maximal correlations occurred for most hays at 48 to 96 hr. Regressions for each duration were calculated and were used to estimate durations where equal in vitro and in vivo values should occur. Differences between kinds of hay and interactions between growth stages hindered improvement of the assay procedure by simple adjustments in fermentation duration.Optimal estimates of digestibility and intake occurred at the same fermentation durations. This was attributed to the recognized relationship between digestibility and intake of forage. A change of one unit in the in vitro digestibility was associated with an 18% greater change in intake of grass hay than of alfalfa hay, but at 70% digestibility both kinds of hay were eaten in equal amounts.The optimal fermentation duration for a general assay to predict digestibility and intake was about 48 hr. Further improvements appeared to require knowledge about differences in kinds and growth stages of hay, in their physical and chemical reaction to in vivo mastication and digestion as compared with grinding and in vitro digestion.

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Studies on forage cell walls

The Journal of Agricultural Science ◽

10.1017/s0021859600057750 ◽

1973 ◽

Vol 80 (2) ◽

pp. 283-296 ◽

Cited By ~ 2

Author(s):

W. R. McManus ◽

M. L. Bigham

Keyword(s):

Cell Wall ◽

Dry Matter ◽

Dry Matter Digestibility ◽

True Digestibility ◽

Faecal Nitrogen ◽

Highly Correlated ◽

Future Work ◽

The Relationship

SummaryFood intake prediction relationships were developed from in vitro dry-matter digestibility determinations on food and resultant faecal material for a number of diets ranging from low quality roughage to high quality irrigated pastures.The relationship between true digestibility in vitro and in vitro food dry-matter digestibility was curvilinear, although true digestibility of food dry matter in vivo was highly correlated with apparent digestibility of food dry matter in vivo. The latter relationship was linear.For 122 sheep observations on voluntary dry-matter intake incorporating 11 diet types, introduction of either of the terms, cell-wall concentration in food: cell-wall concentration in the resultant faeces (CWFo/CWFe), or its converse, into conventional faecal index relationships did not increase precision of intake prediction using faecal nitrogen as an indicator substance. However, significant intake prediction relationships using food:faeces cell-wall ratios were generated.Values for in vitro digestibility of food and resultant faeces dry matter expressed as either a ratio (R) or as a difference (delta) yielded useful prediction relationships. For ‘green’ and for ‘dry’ classifications of the feedstuff's investigated some of these new relationships were either equal to or superior to the predictive efficiency of conventional faecal index relationships.Reasons are discussed for use of maximum potential in vitro digestibility values for food and faecal dry matter in such relationships in future work rather than a conventional 48 h fermentation.

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