A cotyledonary agglutinin from Luetzelburgia auriculata inhibits the fungal growth of Colletotrichum lindemuthianum, Fusarium solani and Aspergillus niger and impairs glucose-stimulated acidification of the incubation medium by Saccharomyces cerevisiae cells

Plant Science ◽  
2005 ◽  
Vol 169 (3) ◽  
pp. 629-639 ◽  
Author(s):  
Vânia M.M. Melo ◽  
Ilka M. Vasconcelos ◽  
Valdirene M. Gomes ◽  
Maura Da Cunha ◽  
Arlete A. Soares ◽  
...  
1996 ◽  
Vol 42 (6) ◽  
pp. 533-538 ◽  
Author(s):  
A. R. Podile ◽  
A. P. Prakash

A biocontrol rhizobacterial strain of Bacillus subtilis AF 1 grown for 6 h was coinoculated with Aspergillus niger at different time intervals and microscopic observations revealed adherence of bacterial cells to the fungal mycelium. Bacterial cells multiplied in situ and colonized the mycelial surface. Growth of AF 1 resulted in damage to the cell wall, followed by lysis. AF 1 inoculation into media containing A. niger at 0, 6, and 12 h suppressed >90% fungal growth, while in 18- and 24-h cultures fungal growth inhibition was 70 and 56%, respectively, in terms of dry weight. In dual culture the fungal growth was not accompanied by formation of spores. The mycelial preparation of A. niger as principal carbon source supported the growth of B. subtilis, as much as chitin. Extracellular protein precipitate from B. subtilis culture filtrate had a significant growth-retarding effect on A. niger. Groundnut seeds bacterized with B. subtilis showed a reduced incidence of crown rot in A. niger infested soil, suggesting a possible role of B. subtilis in biological control of A. niger.Key words: mycolytic bacteria, Bacillus subtilis, Aspergillus niger, biological control.


2009 ◽  
Vol 59 (4) ◽  
pp. 243-247 ◽  
Author(s):  
Margit Winkler ◽  
Ondřej Kaplan ◽  
Vojtěch Vejvoda ◽  
Norbert Klempier ◽  
Ludmila Martínková

1977 ◽  
Vol 89 (1) ◽  
pp. 235-238 ◽  
Author(s):  
P. E. Russell ◽  
A. E. A. Mussa

SummaryTwo systemic fungicides, benomyl and thiabendazole, were more active than the non-systemic fungicide Drazoxolon in inhibiting fungal growth in vitro. A similar pattern was obtained in glasshouse trials with benomyl and thiabendazole giving adequate protection at low concentrations while Drazoxolon was ineffective unless applied at 50% the commercial product concentration. A field trial using thiabendazole, Drazoxolon and a mixture of benomyl and thiram confirmed the glasshouse results.Some phytotoxicity was noticed with high concentrations of both benomyl and thiabendazole, but satisfactory disease control was achieved using fungicide concentrations which did not induce phytotoxicity.


2016 ◽  
Vol 51 (12) ◽  
pp. 1929-1936 ◽  
Author(s):  
Raquel Villamizar-Gallardo ◽  
Johann Faccelo Osma Cruz ◽  
Oscar Orlando Ortíz-Rodriguez

Abstract: The objective of this work was to evaluate the microbicidal effect of silver nanoparticles (AgNPs) on potentially toxigenic fungi affecting cocoa (Theobroma cacao) crops. These fungi, isolated from diseased cocoa pods, were characterized phenotypically and genotypically. The microbicidal effect was assessed by measuring radial mycelial growth, in synthetic culture media, and at different AgNP concentrations in plant tissues. The inhibition effect was monitored in Petri dishes, and changes in fungal structures were observed through scanning electron microscopy. Two potentially toxigenic fungi were highly prevalent: Aspergillus flavus and Fusarium solani. The inhibition assays, performed in liquid and solid synthetic culture media, showed that AgNPs did not significantly affect the growth of these fungi, even at the highest concentration (100 ppm). By contrast, they showed a positive inhibitory effect in plant tissues, especially in the cortex, when infected with A. flavus, in which an 80 ppm dose completely inhibited fungal growth. However, once fungi have managed to penetrate inside the pods, their growth is unavoidable, and AgNP effect is reduced. On F. solani, the studied nanomaterial only induced some texture and pigmentation changes. The microbicidal effect of chemically synthesized silver nanoparticles is greater in plant tissues than in culture media.


2021 ◽  
Vol 57 (5) ◽  
pp. 148-161
Author(s):  
Thị Anh Thy Châu ◽  
Thị Yến Nhung Đặng ◽  
Khởi Nghĩa Nguyễn

Mục tiêu của nghiên cứu nhằm khảo sát khả năng hòa tan lân dưới một số điều kiện môi trường khác nhau và đối kháng với nấm bệnh Fusarium solani của dòng nấm Aspergillus niger H4.7 (H4.7) được phân lập từ đất nông nghiệp ở tỉnh Sóc Trăng ở điều kiện phòng thí nghiệm. Việc khảo sát khả năng hòa tan lân dưới các điều kiện môi trường gồm pH, nồng độ muối NaCl và các dạng lân khó tan khác (FePO4 và AlPO4) được thực hiện trong môi trường NBRIP lỏng, trong khi thí nghiệm khảo sát khả năng đối kháng của dòng nấm H4.7 với dòng nấm Fusarium solani gây bệnh hại cây trồng được thực hiện trên môi trường PDA. Kết quả nghiên cứu cho thấy dòng nấm H4.7 có khả năng hòa tan lân tốt trong môi trường nuôi cấy có pH=7, không bổ sung NaCl và hòa tan tốt các dạng lân khó tan theo thứ tự Ca3(PO4)2 > FePO4 > AlPO4. Ngoài ra, dòng nấm này còn có khả năng đối kháng tốt với dòng nấm Fusarium solani, đặc biệt ở thời điểm 5 ngày sau bố trí với hiệu suất đối kháng đạt 49,2%.


1999 ◽  
Vol 65 (12) ◽  
pp. 5451-5458 ◽  
Author(s):  
Karin Thevissen ◽  
Franky R. G. Terras ◽  
Willem F. Broekaert

ABSTRACT We used an assay based on the uptake of SYTOX Green, an organic compound that fluoresces upon interaction with nucleic acids and penetrates cells with compromised plasma membranes, to investigate membrane permeabilization in fungi. Membrane permeabilization induced by plant defensins in Neurospora crassa was biphasic, depending on the plant defensin dose. At high defensin levels (10 to 40 μM), strong permeabilization was detected that could be strongly suppressed by cations in the medium. This permeabilization appears to rely on direct peptide-phospholipid interactions. At lower defensin levels (0.1 to 1 μM), a weaker, but more cation-resistant, permeabilization occurred at concentrations that correlated with the inhibition of fungal growth. Rs-AFP2(Y38G), an inactive variant of the plant defensin Rs-AFP2 from Raphanus sativus, failed to induce cation-resistant permeabilization in N. crassa. Dm-AMP1, a plant defensin from Dahlia merckii, induced cation-resistant membrane permeabilization in yeast (Saccharomyces cerevisiae) which correlated with its antifungal activity. However, Dm-AMP1 could not induce cation-resistant permeabilization in the Dm-AMP1-resistantS. cerevisiae mutant DM1, which has a drastically reduced capacity for binding Dm-AMP1. We think that cation-resistant permeabilization is binding site mediated and linked to the primary cause of fungal growth inhibition induced by plant defensins.


2020 ◽  
Vol 20 (3) ◽  
Author(s):  
Jorg C de Ruijter ◽  
Kiyohiko Igarashi ◽  
Merja Penttilä

ABSTRACT Processed lignocellulosic biomass is a source of mixed sugars that can be used for microbial fermentation into fuels or higher value products, like chemicals. Previously, the yeast Saccharomyces cerevisiae was engineered to utilize its cellodextrins through the heterologous expression of sugar transporters together with an intracellular expressed β-glucosidase. In this study, we screened a selection of eight (putative) cellodextrin transporters from different yeast and fungal hosts in order to extend the catalogue of available cellobiose transporters for cellobiose fermentation in S. cerevisiae. We confirmed that several in silico predicted cellodextrin transporters from Aspergillus niger were capable of transporting cellobiose with low affinity. In addition, we found a novel cellobiose transporter from the yeast Lipomyces starkeyi, encoded by the gene Ls120451. This transporter allowed efficient growth on cellobiose, while it also grew on glucose and lactose, but not cellotriose nor cellotetraose. We characterized the transporter more in-depth together with the transporter CdtG from Penicillium oxalicum. CdtG showed to be slightly more efficient in cellobiose consumption than Ls120451 at concentrations below 1.0 g/L. Ls120451 was more efficient in cellobiose consumption at higher concentrations and strains expressing this transporter grew slightly slower, but produced up to 30% more ethanol than CdtG.


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