p-Hydroxybenzoylformic acid and (R)-(−)-p-hydroxymandelic acid, two antifungal compounds isolated from the liquid culture of the ectomycorrhizal fungus Pisolithus arhizus

1991 ◽  
Vol 37 (4) ◽  
pp. 258-264 ◽  
Author(s):  
H. H. Kope ◽  
Y. S. Tsantrizos ◽  
J. A. Fortin ◽  
K. K. Ogilvie

Two antifungal compounds isolated from the liquid culture medium of Pisolithus arhizus were identified as p-hydroxybenzoylformic acid and (R)-(−)-p-hydroxymandelic acid and given the trivial names pisolithin A and pisolithin B, respectively. The efficacy of the compounds to inhibit the germination of conidia of Truncatella hartigii was compared with that of commercially available structural analogues, and a comparable range of effectiveness for 50% germination inhibition (GI50) of conidia was recorded. The commercially available synthetic compounds (R)-mandelic acid, benzoylformic acid, and racemic p-hydroxymandelic acid, had GI50 values of 82, 72, and 59 μg/mL, respectively, as compared with the natural compounds pisolithin A, 67 μg/mL, and pisolithin B, 71 μg/mL. Two synthetic S enantiomers of mandelic acid, (S)-mandelic acid and (S)-(+)-p-hydroxymandelic acid, were the most effective compounds, with GI50 values of 31 and 33 μg/mL, respectively. A sodium salt of mandelic acid had no activity below 500 μg/mL. Pisolithin A and pisolithin B were compared with polyoxin D for inhibition of hyphal growth, as measured by protein estimation. Both pisolithin A and B measured higher levels of putative extractable protein than polyoxin D, but less mycelial wet weight was measured. It is suggested that the pisolithins caused a disruption of cell turgor. A measurement of mycelial dry weights of phytopathogens, incubated with the commercially available analogues, benzoylformic acid and racemic p-hydroxymandelic acid, indicated that benzoylformic acid was either more effective than, or as effective as, racemic p-hydroxymandelic acid or nystatin in arresting fungal growth. For ectomycorrhizal fungi confronted with the pisolithins, both compounds were effective in inhibiting the growth of an equal number of fungi, but benzoylformic acid caused a growth stimulation of some ectomycorrhizal fungi. The result of growth stimulation by the compound is discussed. Key words: Pisolithus, antifungal, ectomycorrhizal, biological control.


1991 ◽  
Vol 69 (2) ◽  
pp. 342-346 ◽  
Author(s):  
F. Lapeyrie ◽  
J. Ranger ◽  
D. Vairelles

An easy to use method is presented here to compare and study the mineral phosphate-solubilizing activity of ectomycorrhizal fungi. This technique can discriminate between strains with differing phosphate-solubilizing activities. Synthetic mineral phosphates, crystalline or amorphous, were differentially solubilized by 10 ectomycorrhizal fungi. Natural crystalline phosphates studied do not seem to be solubilized by fungi under similar experimental conditions. Paxillus involutus 1 appears to be able to solubilize calcium phosphates using either ammonium or nitrate nitrogen, but the other isolates were able to effectively solubilize phosphate only in the presence of ammonium. This has implications regarding the possible mechanism used to solubilize phosphate by these isolates. Recrystallization can be seen in the culture medium if calcium ions are present. The type of crystals depends on the phosphate source and on the fungal strain. This technique is suitable for screening a large number of ectomycorrhizal strains. The significance of phosphate-solubilizing activity to plant growth stimulation needs to be determined by field trials. Key words: ectomycorrhizal fungus, phosphate, solubilization.



2021 ◽  
Vol 7 (5) ◽  
pp. 348
Author(s):  
Kristina Habschied ◽  
Vinko Krstanović ◽  
Zvonimir Zdunić ◽  
Jurislav Babić ◽  
Krešimir Mastanjević ◽  
...  

Contamination of crops with phytopathogenic genera such as Fusarium, Aspergillus, Alternaria, and Penicillium usually results in mycotoxins in the stored crops or the final products (bread, beer, etc.). To reduce the damage and suppress the fungal growth, it is common to add antifungal substances during growth in the field or storage. Many of these antifungal substances are also harmful to human health and the reduction of their concentration would be of immense importance to food safety. Many eminent researchers are seeking a way to reduce the use of synthetic antifungal compounds and to implement more eco-friendly and healthier bioweapons against fungal proliferation and mycotoxin synthesis. This paper aims to address the recent advances in the effectiveness of biological antifungal compounds application against the aforementioned fungal genera and their species to enhance the protection of ecological and environmental systems involved in crop growing (water, soil, air) and to reduce fungicide contamination of food derived from these commodities.



Metallomics ◽  
2014 ◽  
Vol 6 (9) ◽  
pp. 1693-1701 ◽  
Author(s):  
Tereza Leonhardt ◽  
Jan Sácký ◽  
Pavel Šimek ◽  
Jiří Šantrůček ◽  
Pavel Kotrba

The first evidence of the existence of gene-encoded Zn-binding peptides that sequester a substantial portion of intracellular Zn in ectomycorrhizal fungi under natural conditions.



2004 ◽  
Vol 70 (12) ◽  
pp. 7413-7417 ◽  
Author(s):  
Mikael Courbot ◽  
Laurent Diez ◽  
Roberta Ruotolo ◽  
Michel Chalot ◽  
Pierre Leroy

ABSTRACT Molecular and cellular mechanisms underlying the sustained metal tolerance of ectomycorrhizal fungi are largely unknown. Some of the main mechanisms involved in metal detoxification appear to involve the chelation of metal ions in the cytosol with thiol-containing compounds, such as glutathione, phytochelatins, or metallothioneins. We used an improved high-performance liquid chromatography method for the simultaneous measurement of thiol-containing compounds from cysteine and its derivatives (γ-glutamylcysteine, glutathione) to higher-molecular-mass compounds (phytochelatins). We found that glutathione and γ-glutamylcysteine contents increased when the ectomycorrhizal fungus Paxillus involutus was exposed to cadmium. An additional compound with a 3-kDa molecular mass, most probably related to a metallothionein, increased drastically in mycelia exposed to cadmium. The relative lack of phytochelatins and the presence of a putative metallothionein suggest that ectomycorrhizal fungi may use a different means to tolerate heavy metals, such as Cd, than do their plant hosts.



2014 ◽  
Vol 31 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Aleksandra Pokojska ◽  
Maria Kampert ◽  
Henryk Różycki ◽  
Edmund Strzelczyk

Studies were carried out to determine the effect of vitamins, temperature and pH on the biomass production by ectomycorrhizal fungi: <i>Laccuria bicolor, Hebeloma crustuliniforme, Suillus bovinus</i> and <i>Pisolithus arhizus</i>. Responses of particular organisms were different Three-factor ANOVA which enables the comparison of the effect of experimental factors on biomass yield has shown that the pH of the medium had a stronger effect on <i>L. bicolor, H. crustuliniforme</i> and <i>S. bovinus</i> than vitamins. Temperature was the factor exerting the strongest effect on the growth of <i>P. tinctorius</i>.



2019 ◽  
Vol 7 (6) ◽  
pp. 169 ◽  
Author(s):  
Seung-Yoon Oh ◽  
Myung Soo Park ◽  
Young Woon Lim

Pine mushroom (Tricholoma matsutake) is one of the most valued ectomycorrhizal fungi in Asia because of its unique pine-like aroma; however, due to exceptionally slow growth of its mycelia in artificial conditions, its cultivation has been largely deemed as not possible. Previous studies have shown that some bacteria and a few Trichoderma species associated with pine mushroom promoted the growth of T. matsutake isolate, but this effect is relatively unexplored. In this study, we investigated the diversity of microfungi in the fairy ring of T. matsutake and their effect on the growth of T. matsutake isolate. From 184 fungal isolates, 28 species were identified based on suitable molecular markers. Penicillium was most frequently observed (16 species), followed by Trichoderma (4 species). Five Zygomycota species showed a high promoting effect on the growth of T. matsutake while the effects of ascomycetes were mixed. The microfungi that promote the growth of T. matsutake can be useful for forest nursery and artificial cultivation of T. matsutake.



2019 ◽  
Vol 32 (10) ◽  
pp. 1324-1335 ◽  
Author(s):  
Natasha T. Forester ◽  
Geoffrey A. Lane ◽  
Catherine M. McKenzie ◽  
Iain L. Lamont ◽  
Linda J. Johnson

In ascomycetes and basidiomycetes, iron-responsive GATA-type transcriptional repressors are involved in regulating iron homeostasis, notably to prevent iron toxicity through control of iron uptake. To date, it has been unknown whether this iron regulator contributes toward mutualistic endosymbiosis of microbes with plants, a system where the endophyte must function within the constraints of an in-host existence, including a dependency on the host for nutrient acquisition. Functional characterization of one such protein, SreA from Epichloë festucae, a fungal endosymbiont of cool-season grasses, indicates that regulation of iron homeostasis processes is important for symbiotic maintenance. The deletion of the sreA gene (ΔsreA) led to iron-dependent aberrant hyphal growth and the gradual loss of endophyte hyphae from perennial ryegrass. SreA negatively regulates the siderophore biosynthesis and high-affinity iron uptake systems of E. festucae, similar to other fungi, resulting in iron accumulation in mutants. Our evidence suggests that SreA is involved in the processes that moderate Epichloë iron acquisition from the plant apoplast, because overharvesting of iron in ΔsreA mutants was detected as premature chlorosis of the host using a hydroponic plant growth assay. E. festucae appears to have a tightly regulated iron management system, involving SreA that balances endophyte growth with its survival and prevents overcompetition with the host for iron in the intercellular niche, thus promoting mutualistic associations. Mutations that interfere with Epichloë iron management negatively affect iron-dependent fungal growth and destabilize mutualistic Epichloë –ryegrass associations.



2015 ◽  
Vol 61 (6) ◽  
pp. 447-450 ◽  
Author(s):  
Yoshimitsu Takakura

Tricholoma matsutake is an ectomycorrhizal fungus that dominates the microbial communities in the soil of pine and spruce forests. The mycorrhizas of this fungus have antimicrobial activity, although factors responsible for the antimicrobial activity have not been fully elucidated. The present study shows that fruit bodies of T. matsutake secreted hydrogen peroxide (H2O2), which was produced by pyranose oxidase, and that the H2O2 thus secreted strongly inhibited the growth of mycelia of the phytopathological fungus Rhizoctonia solani. These findings suggest that fruit bodies of T. matsutake have antifungal activity and that the pyranose oxidase plays an important role in the antifungal activity.



2000 ◽  
Vol 46 (8) ◽  
pp. 753-758 ◽  
Author(s):  
Emma Frändberg ◽  
Carl Petersson ◽  
Lennart N Lundgren ◽  
Johan Schnürer

Streptomyces halstedii K122 was previously found to produce antifungal compounds on solid substrates that inhibit radial growth of fungi among Ascomycetes, Basidiomycetes, Deuteromycetes, Oomycetes, and Zygomycetes, and strongly affected hyphal branching and morphology. During growth of S. halstedii K122 in submerged culture, no antifungal activity could be detected. However, cultivation of S. halstedii in thin (1 mm) liquid substrate layers in large surface-area tissue culture flasks caused intense growth and sporulation of S. halstedii K122, and the biologically active compounds could be extracted from the mycelium with methanol. Antifungal compounds were purified using C18 solid phase extraction and silica gel column chromatography, and identified as bafilomycins B1 and C1, using 2D NMR and FAB MS. Production of bafilomycins, which are specific inhibitors of vacuolar ATPases, has not been reported from S. halstedii previously. Minimum inhibitory concentrations (MIC) of bafilomycins B1 and C1, amphotericin B, and nikkomycin Z were determined at pH 5.5 and 7.0 for the target fungi Aspergillus fumigatus, Mucor hiemalis, Penicillium roqueforti, and Paecilomyces variotii. Penicillium roqueforti was the most sensitive species to all the compounds investigated. The MIC values for amphotericin B were 0.5-4 µg·mL-1 for the fungi tested, and pH did not affect the toxicity. The MIC values for nikkomycin Z ranged from <0.5 µg·mL-1 for Mucor hiemalis to >500 µg·mL-1 for Aspergillus fumigatus, and pH had no influence on toxicity. Bafilomycins B1 and C1 were equally active against the fungal species tested, with MIC values in the range of <0.5-64 µg·mL-1. All fungi were more sensitive to both bafilomycin B1 and C1 at pH 7.0 than at pH 5.5.Key words: antifungal, bafilomycin, MIC, hyphal growth, Streptomyces halstedii.



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