β-Glucosidase excretion in Trichoderma strains with different cell wall bound β-1,3-glucanase activities

1983 ◽  
Vol 29 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Christian P. Kubicek

Two different strains of Trichoderma pseudokoningii (SE1 A8 and SE1 D81) and Trichoderma viride QM 9123 release into the medium different proportions of the total β-glucosidase activity produced. This observation correlates with the degree of β-1,3-glucanase binding to the cell wall found for each strain. DEAE-Sephadex ion-exchange chromatography revealed three peaks of β-1,3-glucanase activity. These three enzymes (enzyme I, enzyme II, and enzyme III) differ in their extent of binding to the cell walls, their activity on isolated cell walls and Trichoderma β-glucan, and their affinity for β-glucan. Of these enzymes, enzyme II shows the largest variation in relative importance among the three strains and is located predominantly within the mural compartment. Enzyme II has the highest activity on and affinity for Trichoderma β-glucan. Enzyme II is also the most active in releasing β-glucosidase from cell walls of strain SE1 A8 (the strain excreting a high proportion of its β-glucosidase into the culture fluid) as well as from strain SE1 D81 (little β-glucosidase activity in the culture fluid). It is concluded that the action of β-1,3-glucanase II on cell wall β-glucan may be responsible for the in vivo release of cell wall bound β-glucosidase into the culture fluid.

1957 ◽  
Vol 106 (3) ◽  
pp. 365-384 ◽  
Author(s):  
Richard M. Krause

The host ranges of bacteriophages for group A, types 1, 6, 12, and 25 and group C streptococci have been determined. The findings indicate that the susceptibility to these phages is primarily a group-specific phenomenon, although it is modified by several factors such as the hyaluronic acid capsule, lysogeny, and possibly the presence of surface proteins. Phage antibody studies indicate that while the group A phages are antigenically related, they are distinct from the group C phage. This is in agreement with the observation that group A phages are not specific for their homologous streptococcal types. The purified group C carbohydrate inactivates group C phage but not the group A phages, thus suggesting that the carbohydrate, a component of the cell wall, may serve as the phage receptor site. It has not been possible to inactivate the group A phages with group A carbohydrate. Phage lysis of groups A and C streptococci is accompanied by fragmentation of the cell wall since the C carbohydrate has been identified serologically and chemically in the supernate of centrifuged lysates. The immediate lysis of groups A and C hemolytic streptococci and their isolated cell walls by an accesory heat-labile lytic factor in fresh group C lysates is also described.


1974 ◽  
Vol 140 (1) ◽  
pp. 47-55 ◽  
Author(s):  
David Jones ◽  
Alex. H. Gordon ◽  
John S. D. Bacon

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.


1959 ◽  
Vol 12 (4) ◽  
pp. 395 ◽  
Author(s):  
J Dainty ◽  
AB Hope

Measurements of ion exchange were made between isolated cell walls of Ohara australis and an external solution. Comparison between intact cells and cell walls showed that nearly all the easily exchangeable cations are located in the cell wall. The wall is hown to consist of "water free space" (W.F.S.) and "Donnan free space" (D.F.S.); the concentration of in diffusible anions in the D.F.S. is about O� 6 equivjl. This finding is contrary to past suggestions that the D.F.S. is in the cytoplasm of plant cells.


1990 ◽  
Vol 269 (2) ◽  
pp. 393-402 ◽  
Author(s):  
P Ryden ◽  
R R Selvendran

1. Polymers were solubilized from the cell walls of parenchyma from mature runner-bean pods with minimum degradation by successive extractions with cyclohexane-trans-1,2-diamine-NNN′N′-tetra-acetate (CDTA), Na2CO3 and KOH to leave the alpha-cellulose residue, which contained cross-linked pectic polysaccharides and Hyp-rich glycoproteins. These were solubilized with chlorite/acetic acid and cellulase. The polymers were fractionated by anion-exchange chromatography, and fractions were subjected to methylation analysis. 2. The pectic polysaccharides differed in their ease of extraction, and a small proportion were highly cross-linked. The bulk of the pectic polysaccharides solubilized by CDTA and Na2CO3 were less branched than those solubilized by KOH. There was good evidence that most of the pectic polysaccharides were not degraded during extraction. 3. The protein-containing fractions included Hyp-rich and Hyp-poor glycoproteins associated with easily extractable pectic polysaccharides, Hyp-rich glycoproteins solubilized with 4M-KOH+borate, the bulk of which were not associated with pectic polysaccharides, and highly cross-linked Hyp-rich glycoproteins. 4. Isodityrosine was not detected, suggesting that it does not have a (major) cross-linking role in these walls. Instead, it is suggested that phenolics, presumably linked to C-5 of 3,5-linked Araf residues of Hyp-rich glycoproteins, serve to cross-link some of the polymers. 5. There were two main types of xyloglucan, with different degrees of branching. The bulk of the less branched xyloglucans were solubilized by more-concentrated alkali. The anomeric configurations of the sugars in one of the highly branched xyloglucans were determined by 13C-n.m.r. spectroscopy. 6. The structural features of the cell-wall polymers and complexes are discussed in relation to the structure of the cell walls of parenchyma tissues.


1968 ◽  
Vol 14 (7) ◽  
pp. 809-811 ◽  
Author(s):  
Chiu-Sheng Wang ◽  
Marvin N. Schwalb ◽  
Philip G. Miles

Mechanically isolated cell walls of normal homokaryons and the morphological mutants thin and puff were fractionated and hydrolyzed by chemical procedures. The yields of fractionated materials and the glucose/hexosamine ratios of acid hydrolysates were determined. Results of statistical analyses of the values obtained from these determinations indicated that single-gene mutations causing the thin and puff mutant forms of this fungus produce specific differences in the composition of cell walls.


1959 ◽  
Vol 110 (6) ◽  
pp. 853-874 ◽  
Author(s):  
Earl H. Freimer ◽  
Richard M. Krause ◽  
Maclyn McCarty

L forms of Group A streptococci have been isolated by the use of penicillin gradient agar plates. Osmotically fragile protoplasts of Group A streptococci have been obtained by the use of Group C phage-associated lysin which lyses Group A streptococci and their isolated cell walls. Membranes surrounding these enzymatically derived protoplasts have been isolated, and chemical and immunological studies indicate that they are free of cell wall carbohydrate and M protein. The streptococcal protoplasts reproduce as colonies which are morphologically indistinguishable from streptococcal L forms. Evidence is presented to show that these two streptococcal derivatives are serologically and physiologically related to each other as well as to the parent streptococcal strain from which they were isolated.


2006 ◽  
Vol 51 (2) ◽  
pp. 510-520 ◽  
Author(s):  
Jeniel Nett ◽  
Leslie Lincoln ◽  
Karen Marchillo ◽  
Randall Massey ◽  
Kathleen Holoyda ◽  
...  

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.


1977 ◽  
Vol 89 (2) ◽  
pp. 327-340 ◽  
Author(s):  
E. Jane Morris ◽  
J. S. D. Bacon

SummaryThe digestibilities of grass cell wall constituents determined in a digestion trial were compared with those obtained by suspending various isolated cell wall preparations in nylon bags in the rumen of a sheep. Particular attention was paid to acetyl groups and to individual sugars, which were determined in both cases by gas liquid chromatography.For dried grass and hay in the digestion trial the cell wall constituents showed digestibilities decreasing in the following order: arabinose, galactose, glucose, xylose, acetyl, lignin.For a leaf cell wall preparation derived from all cell types except mesophyll, the nylon bag technique allowed the same order of digestibilities; rhamnose and uronic acids were also measured and found to be rapidly digested. Mesophyll cell walls placed in nylon bags were more readily digested than non-mesophyll. All the sugars, and also acetyl groups, were digested to the same extent.In a grass cell wall preparation isolated from sheep faeces, tested similarly, xylose and glucose were digested to the same extent, but acetyl groups were less digested.Removal of acetyl groups, using sodium ethoxide, which left the sugar composition and lignin content unchanged, increased the digestibility particularly of the cell walls from faeces.The results are discussed with reference to the relationship between cell wall composition and digestibility.


1968 ◽  
Vol 108 (1) ◽  
pp. 25-31 ◽  
Author(s):  
P. D. Phethean ◽  
L. Jervis ◽  
Mary Hallaway

A method for isolating extensively purified cell walls from higher plants is described; the preparations contain no detectable chloroplast or nuclear material and the protein content (2–5% of the dry wt. of walls) indicates that there is little contamination with cytoplasm. Incubation of purified cell walls with 0·3n-potassium hydroxide for 17hr. at 37° liberates ribonucleotides, which can be purified by adsorption on charcoal and by ion-exchange chromatography. Ribonucleotides are also liberated by incubating the walls with ribonuclease, but not with deoxyribonuclease. The RNA content varies from 0·5 to 6mg./g. dry wt. of walls, depending on the nature and age of the tissue, and at 3mg./g. dry wt. of walls accounts for about 7% of the total RNA of the tissue. Less than 0·2% of the RNA of the walls is due to the presence of bacteria in the preparation. The base composition of the cell-wall RNA is identical with that of ribosomal RNA.


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