scholarly journals Protective activity of the fungal polysaccharides against fusariosis

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 617-619 ◽  
Author(s):  
A. Šrobárová ◽  
G. Kogan ◽  
L. Tamas ◽  
E. Machová

Most of the experiments carried out in the area of plant protection have used chitin and chitosan obtained from the crustacean chitin which production is rather expensive. In our study we have applied the chitin-glucan complex prepared from the waste mycelia of filamentous fungi, from baker’s yeast. Five different polysaccharides have been used for the preparation of water-soluble compounds and the assay of their antifungal activity against plant pathogen Fusarium oxysporum. In the field experiments, application of the polysaccharides led to the diminished infestation as well as to significantly increased productivity of fresh weight of the plants (tomato). The results demonstrated that application of the polysaccharides led to increased production of cell wall and some outher and intermembrane-bound proteins. Although the nature of the observed proteins has not been yet established, it can be speculated that they represent some enzymes involved in the antiinfective defense mechanisms in plants.

2020 ◽  
Vol 1 (1) ◽  
pp. 21-30
Author(s):  
Massimo Malerba ◽  
Raffaella Cerana

Biotic, abiotic stresses and their unpredictable combinations severely reduce plant growth and crop yield worldwide. The different chemicals (pesticides, fertilizers, phytoregulators) so far used to enhance crop tolerance to multistress have a great environmental impact. In the search of more eco-friendly systems to manage plant stresses, chitin, a polysaccharide polymer composed of N-acetyl-D-glucosamine and D-glucosamine and its deacetylated derivative chitosan appear as promising tools to solve this problem. In fact, these molecules, easily obtainable from crustacean shells and from the cell wall of many fungi, are non-toxic, biodegradable, biocompatible and able to stimulate plant productivity and to protect crops against pathogens. In addition, chitin and chitosan can act as bioadsorbents for remediation of contaminated soil and water. In this review we summarize recent results obtained using chitin- and chitosan-based derivatives in plant protection against biotic and abiotic stresses and in recovery of contaminated soil and water.


2005 ◽  
Vol 60 (11-12) ◽  
pp. 921-926 ◽  
Author(s):  
Juraj Majtán ◽  
Grigorij Kogan ◽  
Elena Kováčová ◽  
Katarína Bíliková ◽  
Jozef Šimúth

Carboxymethylated derivatives were prepared from the (1→3)-β-ᴅ-glucan isolated from the cell wall of baker’s yeast Saccharomyces cerevisiae and from the chitin-glucan complex of the mycelium of the industrial filamentous fungus Aspergillus niger. The polysaccharides were applied to peritoneal mouse macrophages and after a 2-h incubation the release of TNF-α by the stimulated macrophages was measured using an enzyme-linked immunosorbent assay. As the third polysaccharide stimulant, a water-soluble derivative of chitin was assayed and the observed cytokine release was compared with the control experiment. In three concentrations of the polysaccharides applied, carboxymethyl glucan revealed a dramatic increase in the TNF-α release, while addition of carboxymethyl chitin-glucan resulted only in a moderate enhancement, and carboxymethyl chitin was inactive. The results indicate that fungal polysaccharides, especially (1→3)-β-ᴅ-glucan, are potent macrophage stimulators and activators of TNF-α release, which implies their potential application in antitumor therapy.


1994 ◽  
Vol 38 (12) ◽  
pp. 2750-2757 ◽  
Author(s):  
M B Kurtz ◽  
C Douglas ◽  
J Marrinan ◽  
K Nollstadt ◽  
J Onishi ◽  
...  

1993 ◽  
Vol 118 (1) ◽  
pp. 141-144 ◽  
Author(s):  
A. Bar-Zur ◽  
A. Schaffer

Ear size and quality traits of various types of maize (Zea mays L.) (Su, su, se, sh2) used as baby corn were evaluated in field experiments. Ear size increased with time (0 to 6 days) after silking. Optimal stage for harvest was at silking for most cultivars and 6 days after silking for the prolific mini-corn cultivars. Sugar content of baby corn ears of all genotypes consisted primarily of glucose and fructose, with only low levels of sucrose. There was no significant increase in sugar content attributable to the su, se, or sh2 genes compared with Su, thus indicating there is no reason to use sweet corn types instead of the higher-yielding Su types. Total soluble sugar content of the genotypes ranged from ≈20 to 30 mg·g-1 fresh weight. Starch and water-soluble polysaccharide (WSP) concentrations in the Su cultivars, which were higher than those in the other endosperm types studied, decreased slightly from 0 to 6 days after silking. However, WSP concentrations were low and not likely to affect quality. Crispness, determined by organoleptic tests, decreased with time of harvest and differed among genotypes.


2019 ◽  
Vol 19 (4) ◽  
pp. 428-438 ◽  
Author(s):  
Nívea P. de Sá ◽  
Ana P. Pôssa ◽  
Pilar Perez ◽  
Jaqueline M.S. Ferreira ◽  
Nayara C. Fonseca ◽  
...  

<p>Background: The increasing incidence of invasive forms of candidiasis and resistance to antifungal therapy leads us to seek new and more effective antifungal compounds. </P><P> Objective: To investigate the antifungal activity and toxicity as well as to evaluate the potential targets of 2- cyclohexylidenhydrazo-4-phenyl-thiazole (CPT) in Candida albicans. </P><P> Methods: The antifungal activity of CPT against the survival of C. albicans was investigated in Caenorhabditis elegans. Additionally, we determined the effect of CPT on the inhibition of C. albicans adhesion capacity to buccal epithelial cells (BECs), the toxicity of CPT in mammalian cells, and the potential targets of CPT in C. albicans. </P><P> Results: CPT exhibited a minimum inhibitory concentration (MIC) value of 0.4-1.9 µg/mL. Furthermore, CPT at high concentrations (>60 x MIC) showed no or low toxicity in HepG2 cells and <1% haemolysis in human erythrocytes. In addition, CPT decreased the adhesion capacity of yeasts to the BECs and prolonged the survival of C. elegans infected with C. albicans. Analysis of CPT-treated cells showed that their cell wall was thinner than that of untreated cells, especially the glucan layer. We found that there was a significantly lower quantity of 1,3-β-D-glucan present in CPT-treated cells than that in untreated cells. Assays performed on several mutant strains showed that the MIC value of CPT was high for its antifungal activity on yeasts with defective 1,3-β-glucan synthase. </P><P> Conclusion: In conclusion, CPT appears to target the cell wall of C. albicans, exhibits low toxicity in mammalian cells, and prolongs the survival of C. elegans infected with C. albicans.</p>


Author(s):  
Anna Biernasiuk ◽  
Anna Berecka-Rycerz ◽  
Anna Gumieniczek ◽  
Maria Malm ◽  
Krzysztof Z. Łączkowski ◽  
...  

Abstract Recently, the occurrence of candidiasis has increased dramatically, especially in immunocompromised patients. Additionally, their treatment is often ineffective due to the resistance of yeasts to antimycotics. Therefore, there is a need to search for new antifungals. A series of nine newly synthesized thiazole derivatives containing the cyclopropane system, showing promising activity against Candida spp., has been further investigated. We decided to verify their antifungal activity towards clinical Candida albicans isolated from the oral cavity of patients with hematological malignancies and investigate the mode of action on fungal cell, the effect of combination with the selected antimycotics, toxicity to erythrocytes, and lipophilicity. These studies were performed by the broth microdilution method, test with sorbitol and ergosterol, checkerboard technique, erythrocyte lysis assay, and reversed phase thin-layer chromatography, respectively. All derivatives showed very strong activity (similar and even higher than nystatin) against all C. albicans isolates with minimal inhibitory concentration (MIC) = 0.008–7.81 µg/mL Their mechanism of action may be related to action within the fungal cell wall structure and/or within the cell membrane. The interactions between the derivatives and the selected antimycotics (nystatin, chlorhexidine, and thymol) showed additive effect only in the case of combination some of them and thymol. The erythrocyte lysis assay confirmed the low cytotoxicity of these compounds as compared to nystatin. The high lipophilicity of the derivatives was related with their high antifungal activity. The present studies confirm that the studied thiazole derivatives containing the cyclopropane system appear to be a very promising group of compounds in treatment of infections caused by C. albicans. However, this requires further studies in vivo. Key points • The newly thiazoles showed high antifungal activity and some of them — additive effect in combination with thymol. • Their mode of action may be related with the influence on the structure of the fungal cell wall and/or the cell membrane. • The low cytotoxicity against erythrocytes and high lipophilicity of these derivatives are their additional good properties. Graphical abstract


Marine Drugs ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 392
Author(s):  
Haomiao Cheng ◽  
Chris Bowler ◽  
Xiaohui Xing ◽  
Vincent Bulone ◽  
Zhanru Shao ◽  
...  

β-Chitin produced by diatoms is expected to have significant economic and ecological value due to its structure, which consists of parallel chains of chitin, its properties and the high abundance of diatoms. Nevertheless, few studies have functionally characterised chitin-related genes in diatoms owing to the lack of omics-based information. In this study, we first compared the chitin content of three representative Thalassiosira species. Cell wall glycosidic linkage analysis and chitin/chitosan staining assays showed that Thalassiosira weissflogii was an appropriate candidate chitin producer. A full-length (FL) transcriptome of T. weissflogii was obtained via PacBio sequencing. In total, the FL transcriptome comprised 23,362 annotated unigenes, 710 long non-coding RNAs (lncRNAs), 363 transcription factors (TFs), 3113 alternative splicing (AS) events and 3295 simple sequence repeats (SSRs). More specifically, 234 genes related to chitin metabolism were identified and the complete biosynthetic pathways of chitin and chitosan were explored. The information presented here will facilitate T. weissflogii molecular research and the exploitation of β-chitin-derived high-value enzymes and products.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zehua Zheng ◽  
Kazuhiro Kawakami ◽  
Dingkun Zhang ◽  
Lumi Negishi ◽  
Mohamed Abomosallam ◽  
...  

AbstractThe Pacific oyster, Crassostrea gigas, is a traditional food worldwide. The soft body of the oyster can easily accumulate heavy metals such as cadmium (Cd). To clarify the molecular mechanism of Cd accumulation in the viscera of C. gigas, we identified Cd-binding proteins. 5,10,15,20-Tetraphenyl-21H,23H-porphinetetrasulfonic acid, disulfuric acid, tetrahydrate, and Cd-binding competition experiments using immobilized metal ion affinity chromatography revealed the binding of water-soluble high molecular weight proteins to Cd, including C. gigas protein disulfide isomerase (cgPDI). Liquid chromatography–tandem mass spectrometry (LC–MS/MS) analyses revealed two CGHC motifs in cgPDI. The binding between Cd and rcgPDI was confirmed through a Cd-binding experiment using the TPPS method. Isothermal titration calorimetry (ITC) revealed the binding of two Cd ions to one molecule of rcgPDI. Circular dichroism (CD) spectrum and tryptophan fluorescence analyses demonstrated that the rcgPDI bound to Cd. The binding markedly changed the two-dimensional or three-dimensional structures. The activity of rcgPDI measured by a PDI Activity Assay Kit was more affected by the addition of Cd than by human PDI. Immunological analyses indicated that C. gigas contained cgPDI at a concentration of 1.0 nmol/g (viscera wet weight). The combination of ITC and quantification results revealed that Cd-binding to cgPDI accounted for 20% of the total bound Cd in the visceral mass. The findings provide new insights into the defense mechanisms of invertebrates against Cd.


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