Some mechanisms involved in growth stimulation of ectomycorrhizal fungi by bacteria

1990 ◽  
Vol 68 (10) ◽  
pp. 2148-2152 ◽  
Author(s):  
R. Duponnois ◽  
J. Garbaye

The stimulating effect of some soil bacteria on the growth of two ectomycorrhizal fungi (Hebeloma crustuliniforme Bull. Saint Amans and Paxillus involutus Batsch. ex Fr.) is considered. Two mechanisms are involved: a direct trophic effect of the bacteria on the fungi, and an indirect effect by detoxication of the fungal culture medium. This is supported by observations that (i) some organic acids (citric acid, malic acid), released by the bacteria, stimulate the growth of the two fungi, and (ii) Paxillus involutus releases polyphenolic substances that are toxic to itself but are metabolized by the bacteria. These first results suggest that some bacteria can have beneficial effects during the saprophytic phase of ectomycorrhizal fungi before mycorrhizal infection.

2021 ◽  
Vol 10 (10) ◽  
pp. 2100
Author(s):  
Hiroshi Sakagami ◽  
Sachie Nakatani ◽  
Ayame Enomoto ◽  
Sana Ota ◽  
Miku Kaneko ◽  
...  

Efficient utilization of alkaline extracts of several plants for the treatment of oral diseases has been reported. To investigate the mechanism of anti-inflammatory activity of alkaline extract of the leaves of Sasa sp. (SE), multi-omics analysis using metabolomics and DNA array was performed. Human gingival fibroblasts (HGFs) were treated for IL-1β to induce inflammation (detected by PGE2 production in culture medium) in the presence or absence of SE. Both IL-1β and SE showed slight hormetic growth stimulation against HGF. SE inhibited PGE2 production dose- and time-dependently. Its inhibitory action was more pronounced by first treating the cells with SE, rather than with IL-1β. At 3 h after IL-1β treatment, 18 amino acids (except cysteine and glutamic acid), total glutathione (GSH, GSSG, Cys-GSH disulfide), Met-sulfoxide, 5-oxoproline, and SAM declined, whereas DNA expressions of AKT, CASP3, and CXCL3 were elevated. These changes were reversed by simultaneous treatment with SE. The present study suggests that the anti-inflammatory action of SE is mediated via various metabolic pathways for cell survival, apoptosis, and leukocyte recruitment.


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.


2015 ◽  
Vol 41 (4) ◽  
pp. 251-255 ◽  
Author(s):  
Daiane Cristina Martins Barros ◽  
Inês Cristina de Batista Fonseca ◽  
Maria Isabel Balbi-Peña ◽  
Sérgio Florentino Pascholati ◽  
Douglas Casaroto Peitl

ABSTRACTThe incidence and the levels of yield loss caused by the white mold of soybean (caused by the fungus Sclerotinia sclerotiorum) have increased in areas of higher altitude at Cerrado and Southern Brazil, causing yield losses of up to 60%. The aim of this study was to select saprobic fungi with the potential to control the white mold of soybean. First, in vitroantagonism screening was carried out to test eight saprobic fungi against S. sclerotiorum. Assessment of S. sclerotiorum mycelial growth was done at four and seven days after its placement on the culture medium. The isolate showing greatest antagonistic effect in all tests/assessments was Myrothecium sp. An in vivo experiment was conducted in a greenhouse and growth chamber, where plants previously treated with eight saprobic fungi were artificially inoculated with S. sclerotiorum. The fungal culture medium (potato-dextrose) and the commercial resistance inducer acibenzolar-S-methyl were used as controls. In the in vivotests, severity of the white mold was assessed at 8, 14 and 21 days after inoculation. The highest reduction percentage in the lesion length was observed for the treatment with Myrothecium sp. (70%), which has the greater potential to be used as biocontrol agent of soybean under the conditions of this experiment.


OCL ◽  
2018 ◽  
Vol 25 (5) ◽  
pp. D508 ◽  
Author(s):  
Elodie Olivier ◽  
Annabelle L’Hermitte ◽  
Patrice Rat ◽  
Melody Dutot

In the European Union, Israel and India, testing cosmetic products or their ingredients on animals is prohibited. In this context, in vitro cell models play a pivotal role in the evaluation of both safety and beneficial effects of cosmetics. Oily formulations, widely used in cosmetics, are complex to study on cell models due to their lipophilic nature that doesn’t match with hydrophilic culture medium. Organic solvents are then required to solubilize oily formulations, but they can interfere with the cellular response. To avoid the use of organic solvents, we developed a method based on cells to evaluate potential beneficial effects of oily formulations. Our method, suitable for high throughput screening, consists in: (1) incubating cells with oily formulations for a short time followed by a recovery period in culture medium and (2) studying cell parameters using robust techniques such as cytofluorometry and fluorescence resonance energy transfer (FRET). Depending on the studied cell parameter, various beneficial effects can be revealed like antioxidant, anti-inflammatory and skin regeneration. The field of cell parameters is open and can be extended to new perspectives in the development of oily formulations.


2000 ◽  
Vol 66 (7) ◽  
pp. 2797-2803 ◽  
Author(s):  
Le Luo Guan ◽  
Hiroyuki Onuki ◽  
Kei Kamino

ABSTRACT The growth of marine bacteria under iron-limited conditions was investigated. Neither siderophore production nor bacterial growth was detected for Pelagiobacter sp. strain V0110 when Fe(III) was present in the culture medium at a concentration of <1.0 μM. However, the growth of V0110 was strongly stimulated by the presence of trace amounts of exogenous siderophore from an alpha proteobacterium, V0902, and 1 nM N-acyl-octanoylhomoserine lactone (C8-HSL), which is known as a quorum-sensing chemical signal. Even though the iron-binding functionality of a hydroxamate siderophore was undetected in the supernatant of V0902, a hydroxamate siderophore was detected in the supernatant of V0110 under the above conditions. These results indicated that hydroxamate siderophore biosynthesis by V0110 began in response to the exogenous siderophore from V0902 when in the presence of C8-HSL; however, C8-HSL production by V0110 and V0902 was not detected. Direct interaction between V0902 and V0110 through siderophore from V0902 was observed in the dialyzing culture. Similar stimulated growth by exogenous siderophore and HSL was also observed in other non-siderophore-producing bacteria isolated from marine sponges and seawater. The requirement of an exogenous siderophore and an HSL for heterologous siderophore production indicated the possibility that cell-cell communication between different species was occurring.


1984 ◽  
Vol 62 (6) ◽  
pp. 1116-1121 ◽  
Author(s):  
F. Lapeyrie ◽  
Monique Perrin ◽  
R. Pepin ◽  
G. Bruchet

Several forms of extracellular crystals have been observed in vitro on a semisynthetic culture medium. The conditions for their formation have not been determined. Their morphology and their localisation on the hyphal surface and in the culture medium have been investigated by means of scanning electron microscopy. These crystals have been identified as dehydrated calcium oxalate (Weddellite) using x-ray diffraction methods. Their high calcium content has been demonstrated with the scanning electron microprobe, by detecting the x-ray emission of calcium. The significance of calcium oxalate production by an ectomycorrhizal fungus is discussed.


Author(s):  
Foozieh Moghadami ◽  
Ramin Hosseini

Background and Objectives: Coenzyme Q10 is an anti-aging agent whose demand is increasing progressively. There are various strategies used for increasing coenzyme Q10 production by microorganisms. In this study, for the first time, we investigated the effect of iron oxide and silver nanoparticles on coenzyme Q10 production by Gluconobacter japonicus FM10. Materials and Methods: In the first step, a preliminary experiment was set and carried out to obtain the minimum inhibitory concentrations of the nanoparticles on the strain FM10. Then the sub-MIC concentrations were used to investigate their effect on coenzyme Q10 production in the stationary and exponential phases of the growth, separately. Results: The results showed that coenzyme Q10 production increased in the presence of the iron oxide and silver nanoparticles. The silver nanoparticles induced 1.9 times higher coenzyme Q10 production. The highest level of coenzyme Q10 was induced when the silver nanoparticles were added to the culture medium at the stationary phase. Conclusion: This should be noticed that so far nanoparticles have been considered as antibacterial agents, rather than being considered to cause probable beneficial effects on the induction of useful products in the microbial world. In this regard, their potential for increasing coenzyme Q10 production has received no attention. However, our present results showed that the nanoparticles can be used to increase the production efficiency of coenzyme Q10 in Gluconobacter.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1822 ◽  
Author(s):  
Marina Borgese ◽  
Ludovica Barone ◽  
Federica Rossi ◽  
Mario Raspanti ◽  
Roberto Papait ◽  
...  

This work is addressed to provide, by in vitro experiments, results on the repercussion that a nanostructured scaffold could have on viability, differentiation and secretion of bioactive factors of human adipose-derived stem cells (hASCs) when used in association to promote angiogenesis, a crucial condition to favour tissue regeneration. To achieve this aim, we evaluated cell viability and morphology by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and microscopy analysis, respectively. We also investigated the expression of some of those genes involved in angiogenesis and differentiation processes utilizing quantitative polymerase chain reaction (qPCR), whereas the amounts of Vascular Endothelial Growth Factor A, Interleukin 6 and Fatty Acid-Binding Protein 4 secreted in the culture medium, were quantified by enzyme-linked immunosorbent assay (ELISA). Results suggested that, in the presence of the scaffold, cell proliferation and the exocytosis of factors involved in the angiogenesis process are reduced; by contrast, the expression of those genes involved in hASC differentiation appeared enhanced. To guarantee cell survival, the construct dimensions are, generally, smaller than clinically required. Furthermore, being the paracrine event the primary mechanism exerting the beneficial effects on injured tissues, the use of conditioned culture medium instead of cells may be convenient.


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