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

1984 ◽  
Vol 103 (2) ◽  
pp. 347-352 ◽  
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.

The relationship between in vitro digestible cell wall and the cell-wall content of forage

1973 ◽  
Vol 81 (3) ◽  
pp. 533-536 ◽  
Author(s):  
K. W. Moir
Keyword(s):  
Cell Wall ◽  
Organic Matter ◽  
Panicum Maximum ◽  
Average Value ◽  
Whole Plant ◽  
Whole Plants ◽  
The Relationship

SUMMARYIn oven-dried whole plants from three regrowths of four varieties of Panicum maximum, leaf and stem of normal and stunted oats at three stages of first growth, leaf and stem of rape and the whole plant of millet, cell wall ranged from 14 to 77% of the organic matter. In vitro digestible cell wall ranged from 13 to 46% of the organic matter and was closely related to the cell wall (residual standard deviation, ± 2·5). In 16 legume hays the average in vitro digestible cell wall was 22·1% of the forage organic matter compared with an average value of 20·5% found previously from in vivo digestibility experiments with legumes. An unsatisfactory feature of the in vitro digestibility determination was that in silages and low quality grass hays, the digestible cell wall was low relative to known in vivo values for these forage types. The separate determinations of cell wall and in vitro digestible cell wall would add to the confidence that can be placed on estimates of in vivo digestibility from laboratory measurements. Often, the determination of cell-wall content is sufficient for this purpose.

scholarly journals Co-operative action by endo- and exo-β-(1→3)-glucanases from parasitic fungi in the degradation of cell-wall glucans of Sclerotinia sclerotiorum (Lib.) de Bary

1974 ◽  
Vol 140 (1) ◽  
pp. 47-55 ◽  
Author(s):  
David Jones ◽  
Alex. H. Gordon ◽  
John S. D. Bacon
Keyword(s):  
Cell Wall ◽  
Sclerotinia Sclerotiorum ◽  
Culture Filtrate ◽  
Cell Walls ◽  
Trichoderma Viride ◽  
Major Constituent ◽  
Coniothyrium Minitans ◽  
Parasitic Fungi ◽  
Complete Breakdown

1. Two fungi, Coniothyrium minitans Campbell and Trichoderma viride Pers. ex Fr., were grown on autoclaved crushed sclerotia of the species Sclerotinia sclerotiorum, which they parasitize. 2. in vitro the crude culture filtrates would lyse walls isolated from hyphal cells or the inner pseudoparenchymatous cells of the sclerotia, in which a branched β-(1→3)-β-(1→6)-glucan, sclerotan, is a major constituent. 3. Chromatographic fractionation of the enzymes in each culture filtrate revealed the presence of several laminarinases, the most active being an exo-β-(1→3)-glucanase, known from previous studies to attack sclerotan. Acting alone this brought about a limited degradation of the glucan, but the addition of fractions containing an endo-β-(1→3)-glucanase led to almost complete breakdown. A similar synergism between the two enzymes was found in their lytic action on cell walls. 4. When acting alone the endo-β-(1→3)-glucanase had a restricted action, the products including a trisaccharide, tentatively identified as 62-β-glucosyl-laminaribiose. 5. These results are discussed in relation to the structure of the cell walls and of their glucan constituents.

scholarly journals Frecuencias de corte y niveles de fertilización nitrogenada en rendimiento y calidad del forrraje de morera (Morus sp.), en Cuyuta, Guatemala

2016 ◽  
Vol 3 ◽  
pp. 48
Author(s):  
Carlos Rodríguez ◽  
Juan A. Quiñones ◽  
Rodrigo Arias
Keyword(s):  
Dry Matter ◽  
Ground Level ◽  
Dry Matter Digestibility ◽  
Yield And Quality ◽  
Whole Plant ◽  
Dual Purpose Cattle ◽  
Whole Plants ◽  
Cutting Height

The trial was conducted at the Centro de Producción Agrícola of ICfA in Cuyuta, Escuintla-Guatemala in order to generate information on the yield and quality of edible mulberry (Morus sp.) roughage treatments consisted of three harvest frequencies (6; 9 and 12 weeks and three fertilization levels of nitrogen (0.40 and 80 kg/ha). A complete randomized block experimental design, with a factorial arrangement (3x3) was used. The cutting height was 0.3 m above the ground level with two sequencies: from August 2nd to September 13 th and from September 13th to December 6th, 1990. In both cases, the 12 week frequency cutting and 80 kg of N were superior to the others (P<=0.01), yielding 6.87 and 6.15 t/ha of dry matter respectively. The yields at 9 weeks were statistically higher than those at 6 weeks. The highest protein percentage of the whole plant, leaves and stalks were produced at 6 weeks. The dry matter digestibility values in vitro showed little variability among treatments, with averages for whole plants, leaves and stalks of 65, 91 and 41 %, respectively. The preceeding data suggests that the mulberry has an excellent potential as a balanced supplement (protein and energy) for dual purpose cattle on the Southern coast of Guatemala.

scholarly journals Melanin Externalization in Candida albicans Depends on Cell Wall Chitin Structures

2010 ◽  
Vol 9 (9) ◽  
pp. 1329-1342 ◽  
Author(s):  
Claire A. Walker ◽  
Beatriz L. Gómez ◽  
Héctor M. Mora-Montes ◽  
Kevin S. Mackenzie ◽  
Carol A. Munro ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Fungal Pathogen ◽  
Cell Walls ◽  
Chitin Synthesis ◽  
Melanin Production ◽  
Content Type ◽  
Encoding Gene ◽  
Chitinase Genes

ABSTRACT The fungal pathogen Candida albicans produces dark-pigmented melanin after 3 to 4 days of incubation in medium containing l-3,4-dihydroxyphenylalanine (l-DOPA) as a substrate. Expression profiling of C. albicans revealed very few genes significantly up- or downregulated by growth in l-DOPA. We were unable to determine a possible role for melanin in the virulence of C. albicans. However, we showed that melanin was externalized from the fungal cells in the form of electron-dense melanosomes that were free or often loosely bound to the cell wall exterior. Melanin production was boosted by the addition of N-acetylglucosamine to the medium, indicating a possible association between melanin production and chitin synthesis. Melanin externalization was blocked in a mutant specifically disrupted in the chitin synthase-encoding gene CHS2. Melanosomes remained within the outermost cell wall layers in chs3Δ and chs2Δ chs3Δ mutants but were fully externalized in chs8Δ and chs2Δ chs8Δ mutants. All the CHS mutants synthesized dark pigment at equivalent rates from mixed membrane fractions in vitro, suggesting it was the form of chitin structure produced by the enzymes, not the enzymes themselves, that was involved in the melanin externalization process. Mutants with single and double disruptions of the chitinase genes CHT2 and CHT3 and the chitin pathway regulator ECM33 also showed impaired melanin externalization. We hypothesize that the chitin product of Chs3 forms a scaffold essential for normal externalization of melanosomes, while the Chs8 chitin product, probably produced in cell walls in greater quantity in the absence of CHS2, impedes externalization.

scholarly journals Evaluation of Antifungal Activity and Mode of Action of New Coumarin Derivative, 7-Hydroxy-6-nitro-2H-1-benzopyran-2-one, againstAspergillusspp.

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Felipe Queiroga Sarmento Guerra ◽  
Rodrigo Santos Aquino de Araújo ◽  
Janiere Pereira de Sousa ◽  
Fillipe de Oliveira Pereira ◽  
Francisco J. B. Mendonça-Junior ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mode Of Action ◽  
Cell Walls ◽  
Coumarin Derivative ◽  
Antifungal Drugs ◽  
Azole Resistance ◽  
Subinhibitory Concentration ◽  
Fungal Cell ◽  
Mycelia Growth

Aspergillusspp. produce a wide variety of diseases. For the treatment of such infections, the azoles and Amphotericin B are used in various formulations. The treatment of fungal diseases is often ineffective, because of increases in azole resistance and their several associated adverse effects. To overcome these problems, natural products and their derivatives are interesting alternatives. The aim of this study was to examine the effects of coumarin derivative, 7-hydroxy-6-nitro-2H-1-benzopyran-2-one (Cou-NO2), both alone and with antifungal drugs. Its mode of action againstAspergillusspp. Cou-NO2was tested to evaluate its effects on mycelia growth and germination of fungal conidia ofAspergillusspp. We also investigated possible Cou-NO2action on cell walls (0.8 M sorbitol) and on Cou-NO2to ergosterol binding in the cell membrane. The study shows that Cou-NO2is capable of inhibiting both the mycelia growth and germination of conidia for the species tested, and that its action affects the structure of the fungal cell wall. At subinhibitory concentration, Cou-NO2enhanced thein vitroeffects of azoles. Moreover, in combination with azoles (voriconazole and itraconazole) Cou-NO2displays an additive effect. Thus, our study supports the use of coumarin derivative 7-hydroxy-6-nitro-2H-1-benzopyran-2-one as an antifungal agent againstAspergillusspecies.

PREDICTED FORAGE VALUE OF WHOLE PLANT CEREALS

1975 ◽  
Vol 55 (4) ◽  
pp. 975-986 ◽  
Author(s):  
L. J. FISHER ◽  
D. B. FOWLER
Keyword(s):  
Organic Matter ◽  
Dry Matter ◽  
Dry Weight ◽  
Neutral Detergent Fiber ◽  
Dry Matter Yield ◽  
Acid Detergent Fiber ◽  
Whole Plant ◽  
Digestible Organic Matter ◽  
Forage Value

Dry matter yield, percent dry weight, in vitro digestible dry matter, in vitro digestible organic matter, neutral detergent fiber, acid detergent fiber, ash and hemicellulose contents were determined for spring- and fall-sown common wheat, barley, rye and triticale and spring-sown durum wheat and oats for the period from late boot to maturity. Differences among cultivars and stages of maturity were significant for all parameters. These differences were accompanied by stage of maturity interactions. Consideration of the interrelationships among these parameters revealed that level of in vitro digestible dry matter was reflected in measures of acid detergent fiber and ash or percent dry weight. Further analyses indicated that differences in digestibility due to stage of maturity were primarily reflected by changes in ash or percent dry weight, while differences in digestibility among cultivars were mainly attributable to differences in acid detergent fiber.

VARIABILITY OF IN VITRO DIGESTIBILITY AMONG CLONES OF BROMEGRASS AND ORCHARDGRASS

1968 ◽  
Vol 48 (1) ◽  
pp. 67-73 ◽  
Author(s):  
B. R. Christie ◽  
D. N. Mowat
Keyword(s):  
Dactylis Glomerata ◽  
Bromus Inermis ◽  
In Vitro Digestibility ◽  
Phenotypic Characteristics ◽  
Whole Plant ◽  
Stems And Leaves ◽  
Dactylis Glomerata L ◽  
Whole Plants ◽  
Genotypic Effects

Individual clones of bromegrass (Bromus inermis Leyss) and orchardgrass (Dactylis glomerata L.) were harvested at corresponding stages of maturity within each species. The orchardgrass clones were harvested in 1962, and the in vitro digestibility (IVD) was based on the whole plant. Bromegrass clones, harvested in 1965 and 1966, were separated into leaves and stems. The IVD of each component was determined, and from these, the IVD for the whole plant was estimated.Among 444 orchardgrass clones, IVD values ranged from 49 to 68%. Most of the variation was attributed to genotypic effects. For approximately 250 clones of bromegrass, IVD values ranged from 66 to 75%, 58 to 73%, and 62 to 74%, for leaves, stems, and whole plants respectively. Over the 2-year period, differences among stems and whole plants were significant. Correlations between leaf and stem digestibilities were significant but of low magnitude. Ten clones of bromegrass had stems and leaves of equal digestibility.In bromegrass, IVD values showed no relationship to several phenotypic characteristics.

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

1995 ◽  
Vol 46 (6) ◽  
pp. 1111 ◽  
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.

scholarly journals Putative Role of β-1,3 Glucans in Candida albicans Biofilm Resistance

2006 ◽  
Vol 51 (2) ◽  
pp. 510-520 ◽  
Author(s):  
Jeniel Nett ◽  
Leslie Lincoln ◽  
Karen Marchillo ◽  
Randall Massey ◽  
Kathleen Holoyda ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Cell Viability ◽  
Amphotericin B ◽  
Cell Walls ◽  
Positive Impact ◽  
Indirect Evidence ◽  
Phenotypic Properties

ABSTRACT Biofilms are microbial communities, embedded in a polymeric matrix, growing attached to a surface. Nearly all device-associated infections involve growth in the biofilm life style. Biofilm communities have characteristic architecture and distinct phenotypic properties. The most clinically important phenotype involves extraordinary resistance to antimicrobial therapy, making biofilm infections very difficulty to cure without device removal. The current studies examine drug resistance in Candida albicans biofilms. Similar to previous reports, we observed marked fluconazole and amphotericin B resistance in a C. albicans biofilm both in vitro and in vivo. We identified biofilm-associated cell wall architectural changes and increased β-1,3 glucan content in C. albicans cell walls from a biofilm compared to planktonic organisms. Elevated β-1,3 glucan levels were also found in the surrounding biofilm milieu and as part of the matrix both from in vitro and in vivo biofilm models. We thus investigated the possible contribution of β-glucans to antimicrobial resistance in Candida albicans biofilms. Initial studies examined the ability of cell wall and cell supernatant from biofilm and planktonic C. albicans to bind fluconazole. The cell walls from both environmental conditions bound fluconazole; however, four- to fivefold more compound was bound to the biofilm cell walls. Culture supernatant from the biofilm, but not planktonic cells, bound a measurable amount of this antifungal agent. We next investigated the effect of enzymatic modification of β-1,3 glucans on biofilm cell viability and the susceptibility of biofilm cells to fluconazole and amphotericin B. We observed a dose-dependent killing of in vitro biofilm cells in the presence of three different β-glucanase preparations. These same concentrations had no impact on planktonic cell viability. β-1,3 Glucanase markedly enhanced the activity of both fluconazole and amphotericin B. These observations were corroborated with an in vivo biofilm model. Exogenous biofilm matrix and commercial β-1,3 glucan reduced the activity of fluconazole against planktonic C. albicans in vitro. In sum, the current investigation identified glucan changes associated with C. albicans biofilm cells, demonstrated preferential binding of these biofilm cell components to antifungals, and showed a positive impact of the modification of biofilm β-1,3 glucans on drug susceptibility. These results provide indirect evidence suggesting a role for glucans in biofilm resistance and present a strong rationale for further molecular dissection of this resistance mechanism to identify new drug targets to treat biofilm infections.

scholarly journals Staphylococcus aureus cell wall structure and dynamics during host-pathogen interaction

2021 ◽  
Vol 17 (3) ◽  
pp. e1009468
Author(s):  
Joshua A. F. Sutton ◽  
Oliver T. Carnell ◽  
Lucia Lafage ◽  
Joe Gray ◽  
Jacob Biboy ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Walls ◽  
Ex Vivo ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Bacterial Cells ◽  
Human Macrophages ◽  
Structure And Dynamics

Peptidoglycan is the major structural component of the Staphylococcus aureus cell wall, in which it maintains cellular integrity, is the interface with the host, and its synthesis is targeted by some of the most crucial antibiotics developed. Despite this importance, and the wealth of data from in vitro studies, we do not understand the structure and dynamics of peptidoglycan during infection. In this study we have developed methods to harvest bacteria from an active infection in order to purify cell walls for biochemical analysis ex vivo. Isolated ex vivo bacterial cells are smaller than those actively growing in vitro, with thickened cell walls and reduced peptidoglycan crosslinking, similar to that of stationary phase cells. These features suggested a role for specific peptidoglycan homeostatic mechanisms in disease. As S. aureus penicillin binding protein 4 (PBP4) has reduced peptidoglycan crosslinking in vitro its role during infection was established. Loss of PBP4 resulted in an increased recovery of S. aureus from the livers of infected mice, which correlated with enhanced fitness within murine and human macrophages. Thicker cell walls correlate with reduced activity of peptidoglycan hydrolases. S. aureus has a family of 4 putative glucosaminidases, that are collectively crucial for growth. Loss of the major enzyme SagB, led to attenuation during murine infection and reduced survival in human macrophages. However, loss of the other three enzymes Atl, SagA and ScaH resulted in clustering dependent attenuation, in a zebrafish embryo, but not a murine, model of infection. A combination of pbp4 and sagB deficiencies resulted in a restoration of parental virulence. Our results, demonstrate the importance of appropriate cell wall structure and dynamics during pathogenesis, providing new insight to the mechanisms of disease.

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