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Sustainable alternatives to 1,3-dichloropropene for controlling root-knot nematodes and fungal pathogens in melon crops in Mediterranean soils: Efficacy and effects on soil quality
2019
Montiel-Rozas, María del Mar | Hurtado-Navarro, María | Díez-Rojo, Miguel Ángel | Pascual, José A. (José Antonio) | Ros, Margarita
The control of agricultural pests is key to maintain economically viable crops. Increasing environmental awareness, however, is leading to more restrictive European policies regulating the use of certain pesticides due to their impact on human health and the soil system. Given this context, we evaluated the efficacy of three alternatives to the soil fumigant 1,3-dichloropropene (1,3-D), which is currently banned in Europe: two non-fumigant nematicides [oxamyl (OX) and fenamiphos (FEN)] and the soil fumigant dimethyl disulfide (DMDS). We analysed the efficiency of these pesticides against root-knot nematodes and soil fungal pathogens (determined by qPCR) as well as the soil biological quality after treatments application (estimated by enzyme activities). Among treatments, 1,3-D and DMDS significantly reduced nematode populations. FEN was more effective in sandy soil, while OX had no effect in any soil. OX and FEN had no effect on fungal pathogens, whereas DMDS reduced the abundance of Rhizoctonia solani and Fusarium solani at the root level in clay-loam soil. Soil quality decreased after treatment application but then recovered throughout the experiment, indicating the possible dissipation of the pesticides. Our findings support DMDS as a potential sustainable alternative for controlling root-knot nematodes and fungal pathogens due to its effectiveness in both studied soils, although its negative impact on soil biological quality in sandier soils must be taken into account.Main finding of the work. DMDS is a reliable alternative to 1,3-D for controlling agricultural pest but its inhibitory effect on soil enzyme activities varied according to the soil characteristics.
Показать больше [+] Меньше [-]A sustainable Decision Support System for soil bioremediation of toluene incorporating UN sustainable development goals
2022
Akbarian, Hadi | Jalali, Farhad Mahmoudi | Gheibi, Mohammad | Hajiaghaei-Keshteli, Mostafa | Akrami, Mehran | Sarmah, Ajit K.
Decision Support System (DSS) is a novel approach for smart, sustainable controlling of environmental phenomena and purification processes. Toluene is one of the most widely used petroleum products, which adversely impacts on human health. In this study, Fusarium Solani fungi are utilized as the engine of the toluene bioremediation procedure for the monitoring part of DSS. Experiments are optimized by Central Composite Design (CCD) - Response Surface Methodology (RSM), and the behavior of the mentioned fungi is estimated by M5 Pruned model tree (M5P), Gaussian Processes (GP), and Sequential Minimal Optimization (SMOreg) algorithms as the prediction section of DSS. Finally, the control stage of DSS is provided by integrated Petri Net modeling and Failure Modes and Effects Analysis (FMEA). The findings showed that Aeration Intensity (AI) and Fungi load/Biological Waste (F/BW) are the most influential mechanical and biological factors, with P-value of 0.0001 and 0.0003, respectively. Likewise, the optimal values of main mechanical parameters include AI, and the space between pipes (S) are equal to 13.76 m³/h and 15.99 cm, respectively. Also, the optimum conditions of biological features containing F/BW and pH are 0.001 mg/g and 7.56. In accordance with the kinetic study, bioremediation of toluene by Fusarium Solani is done based on a first-order reaction with a 0.034 s-1 kinetic coefficient. Finally, the machine learning practices showed that the GP (R2 = 0.98) and M5P (R2 = 0.94) have the most precision for predicting Removal Percentage (RP) for mechanical and biological factors, respectively. At the end of the present research, it is found that by controlling seven possible risk factors in bioremediation operation through the FMEA- Petri Net technique, efficiency of the process can be adjusted to optimum value.
Показать больше [+] Меньше [-]Experimental increase in availability of a PAH complex organic contamination from an aged contaminated soil: Consequences on biodegradation
2013
Cébron, Aurélie | Faure, Pierre | Lorgeoux, Catherine | Ouvrard, Stéphanie | Leyval, Corinne
Although high PAH content and detection of PAH-degraders, the PAH biodegradation is limited in aged-contaminated soils due to low PAH availability (i.e., 1%). Here, we tried to experimentally increase the soil PAH availability by keeping both soil properties and contamination composition. Organic extract was first removed and then re-incorporated in the raw soil as fresh contaminants. Though drastic, this procedure only allowed a 6-time increase in the PAH availability suggesting that the organic constituents more than ageing were responsible for low availability. In the re-contaminated soil, the mineralization rate was twice more important, the proportion of 5–6 cycles PAH was higher indicating a preferential degradation of lower molecular weight PAH. The extraction treatment induced bacterial and fungal community structures modifications, Pseudomonas and Fusarium solani species were favoured, and the relative quantity of fungi increased. In re-contaminated soil the percentage of PAH-dioxygenase gene increased, with 10 times more Gram negative representatives.
Показать больше [+] Меньше [-]Impact of rhizosphere microorganisms on arsenic (As) transformation and accumulation in a traditional Chinese medical plant
2021
Li, Jiao-Jiao | Yang, Long | Miao, Cui-Ping | Teng, Ya-Jun | Fu, Zi-Hao | Cheng, Chang-Lei | Chang, Xue-Xiu | Qian, Yu | Zhao, Li-Xing
Panax notoginseng is an important traditional medicinal plant, but the commercial value is threatened by root-rot disease caused by rhizosphere microbes and a potential health risk caused by plant arsenic (As) accumulation. Whether rhizospheric microbes isolated from P. notoginseng rhizosphere soil could impact As uptake and transport into P. notoginseng is not yet known. Among the three root-rot disease-causing pathogens Fusarium flocciferum (PG 1), Fusarium oxysporum (PG 2), and Fusarium solani (PG 3) and one root-rot disease biocontrol fungus Trichoderma koningiopsis (FC 1) and five biocontrol-exerting bacterial species Bacillus siamensis (BC 1), Delftia acidovorans (BC 2), Brevibacillus formosus (BC 3), Mortierella alpine (BC 4), and Bacillus subtilis (BC 5), one As-resistant pathogen and four biocontrol microorganisms with As-resistant ability were identified. The As-transforming ability of the identified fungi and bacteria was ranked in the order of FC 1 > PG 1 and BC 2 > BC 3 > BC 1, respectively. Then, the As-resistant biocontrol and pathogenic microbes were initiated to colonize the rhizosphere of 1-year-old P. notoginseng seedlings growing in artificially As(V)-contaminated soil to evaluate the impact of microbe inoculation on P. notoginseng As uptake and transport capacity. Concentration of As in P. notoginseng tissues decreased in the order of the sequence stem > root > leaf. Compared to treatment without colonization by microorganism, inoculation with microorganisms increased As root uptake efficiency and root As concentration, especially under treatment of inoculation by BC 2 and PG 1 + BC 2. As transport efficiency from root to stem decreased by inoculation with microorganism, especially under treatment with inoculation of BC 2 and PG 1 + BC 2. However, the impact of microorganism colonization on As stem to leaf transport efficiency was not obvious. In summary, inoculation with rhizosphere microbes may increase As accumulation in P. notoginseng root, especially when using bacteria with high As transformation ability. Therefore, it is necessary to evaluate the As transformation capacity before applying biological control microorganism to the rhizosphere of P. notoginseng.
Показать больше [+] Меньше [-]Optimization of process parameters for the synthesis of silver nanoparticles from Piper betle leaf aqueous extract, and evaluation of their antiphytofungal activity
2020
Khan, Sadaf | Singh, Simran | Gaikwad, Swapnil | Nawani, Neelu | Junnarkar, Manisha | Pawar, Sarika Vishnu
Biological methods offer eco-friendly and cost-effective alternatives for the synthesis of silver nanoparticles (AgNPs). The present study highlights a green process where AgNPs were synthesized and optimized by using silver nitrate (AgNO₃) and the aqueous extract of Piper betle (Pbet) leaf as the reducing and capping agent. The stable and optimized process for the synthesis of Pbet-AgNPs was exposure of reaction mixture into the sunlight for 40 min, pH 9.0, and 2 mM AgNO₃ using 1:4 diluted Pbet leaf aqueous extract. The optimized Pbet-AgNPs were characterized by UV–visible spectroscopy, high-resolution field emission scanning electron microscopy (FE-SEM), X-ray diffractometry (XRD), and Fourier-transform infrared spectroscopy (FTIR). The prepared Pbet-AgNPs were spherical in shape with size in the range of 6–14 nm. These nanoparticles were stable for 6 months in aqueous solution at room temperature under dark conditions. The biogenic synthesized Pbet-AgNPs are found to have significant antifungal activity against plant pathogenic fungi, Alternaria brassicae and Fusarium solani. Synthesized Pbet-AgNPs potentially reduced the fungal growth in a dose-dependent manner. Microscopic observation of treated mycelium showed that Pbet-AgNPs could disrupt the mycelium cell wall and induce cellular permeability. Protein leakage assay supports these findings. Overall, this study revealed the efficacy of green synthesized AgNPs to control the plant fungal pathogens. Pbet leaves are a rich source of phenolic biomolecule(s). It was hypothesized that these biomolecule(s) mediated metal reduction reactions. In this context, the present work investigates the phytobiomolecule(s) of the aqueous extract of Pbet leaves using high-resolution liquid chromatography–mass spectroscopy (HR-LCMS) method. The analysis revealed that eugenol, chavicol, and hydroxychavicol were present in the Pbet aqueous extract.
Показать больше [+] Меньше [-]Enhanced reduction of phenol content and toxicity in olive mill wastewaters by a newly isolated strain of Coriolopsis gallica
2014
Daâssi, Dalel | Belbahri, Lassaad | Vallat, Armelle | Woodward, Steve | Nasri, Moncef | Mechichi, Tahar
The search for novel microorganisms able to degrade olive mill wastewaters (OMW) and withstand the toxic effects of the initially high phenolic concentrations is of great scientific and industrial interest. In this work, the possibility of reducing the phenolic content of OMW using new isolates of fungal strains (Coriolopsis gallica, Bjerkandera adusta, Trametes versicolor, Trichoderma citrinoviride, Phanerochaete chrysosporium, Gloeophyllum trabeum, Trametes trogii, and Fusarium solani) was investigated. In vitro, all fungal isolates tested caused an outstanding decolorization of OMW. However, C. gallica gave the highest decolorization and dephenolization rates at 30 % v/v OMW dilution in water. Fungal growth in OMW medium was affected by several parameters including phenolic compound concentration, nitrogen source, and inoculum size. The optimal OMW medium for the removal of phenolics and color was with the OMW concentration (in percent)/[(NH₄)₂SO₄]/inoculum ratio of 30:6:3. Under these conditions, 90 and 85 % of the initial phenolic compounds and color were removed, respectively. High-pressure liquid chromatography analysis of extracts from treated and untreated OMW showed a clear and substantial reduction in phenolic compound concentrations. Phytotoxicity, assessed using radish (Raphanus sativus) seeds, indicated an increase in germination index of 23–92 % when a 30 % OMW concentration was treated with C. gallica in different dilutions (1/2, 1/4, and 1/8).
Показать больше [+] Меньше [-]Antifungal efficiency of a lipopeptide biosurfactant derived from Bacillus subtilis SPB1 versus the phytopathogenic fungus, Fusarium solani
2015
Mnif, Ines | Hammami, Ines | Triki, Mohamed Ali | Azabou, Manel Cheffi | Ellouze-Chaabouni, Semia | Ghribi, Dhouha
Bacillus subtilis SPB1 lipopeptides were evaluated as a natural antifungal agent against Fusarium solani infestation. In vitro antifungal assay showed a minimal inhibitory concentration of about 3 mg/ml with a fungicidal mode of action. In fact, treatment of F. solani by SPB1 lipopeptides generated excessive lyses of the mycelium and caused polynucleation and destruction of the related spores together with a total inhibition of spore production. Furthermore, an inhibition of germination potency accompanied with a high spore blowing was observed. Moreover, in order to be applied in agricultural field, in vivo antifungal activity was proved against the dry rot potato tubers caused by F. solani. Preventive treatment appeared as the most promising as after 20 days of fungi inoculation, rot invasion was reduced by almost 78 %, in comparison to that of non-treated one. When treating infected tomato plants, disease symptoms were reduced by almost 100 % when applying the curative method. Results of this study are very promising as it enables the use of the crude lipopeptide preparation of B. subtilis SPB1 as a potent natural fungicide that could effectively control the infection of F. solani in tomato and potato tubers at a concentration similar to the commercial fungicide hymexazol and therefore prevent the damage of olive tree.
Показать больше [+] Меньше [-]Metabolic adaptation of fungal strains in response to contamination by polychlorinated biphenyls
2019
Périgon, Sophie | Massier, Martin | Germain, Joaquim | Binet, Marie-Noëlle | Legay, Nicolas | Mouhamadou, Bello
Polychlorinated biphenyls (PCBs) represent a large group of recalcitrant environmental pollutants. Up to now, many studies have focused on bioremediation of PCBs by fungal strains; however, the mechanisms of adaptation of these strains towards PCBs remain unknown despite their importance in developing effective bioremediation processes. We studied five species, each consisting of two strains isolated either from PCB-polluted or PCB-unpolluted substrates (control strains). We investigated their responses to PCB contamination by studying their tolerance to PCBs, their ability to reduce these pollutants, and their expression level of Laccase genes. In Thermothelomyces thermophila, Thermothelomyces heterothallica, Thermoascus crustaceus, and Fusarium solani, all the studied strains showed a similar tolerance and PCB degradation regardless of their origin. In Schizophyllum commune, while both strains showed similar resistance to PCBs, i.e., PCBs and their degradation products presented no toxicity for these strains, the rate of PCB degradation of the strain from a PCB-polluted environment was significantly slightly higher. The PCB degradation did not correlate with the expression level of genes encoding Laccases. These results demonstrate that the tolerance and PCB degradation by the fungal strains, which did not involve Laccase genes, required different adaptation systems which seem to be constitutive or rapidly inducible by PCB according to the fungal species.
Показать больше [+] Меньше [-]Effect of compost tea containing phosphogypsum on potato plant growth and protection against Fusarium solani infection
2018
Samet, Mariem | Charfeddine, Mariam | Kamoun, Lotfi | Nouri-Ellouze, Oumèma | Gargouri-Bouzid, Radhia
Three composts made of industrial wastes were prepared by mixing olive oil mill waste water (OMW), olive pomace, coffee grounds, and phosphogypsum (0, 10, and 30%). Potato plants (Solanum tuberosum) cultivated in a greenhouse were used to screen compost tea suppressive ability. All compost tea treatments inhibited Fusarium solani growth and improved plant growth and response to F. solani infection. The antagonistic effects of the different treatments were associated with a marked increase of the antioxidant enzymes and PR (pathogenesis related) protein expression and a decrease of disease severity. These results also showed that plant growth and disease suppression were improved by application of phosphogypsum-supplemented compost teas (A10 and A30). This enhancement can be attributed to the influence of phosphogypsum on nutrient elements and microbial diversity in the resulting compost teas.
Показать больше [+] Меньше [-]Lipid metabolism and benzo[a]pyrene degradation by Fusarium solani: an unexplored potential
2018
Delsarte, Isabelle | Rafin, Catherine | Mrad, Fida | Veignie, Etienne
In a search for indigenous soil saprotrophic fungi for bioremediation purposes, Fusarium solani, a saprotrophic fungus belonging to the phylum Ascomycota, was isolated from a fossil carbon contaminated soil. The effect of the carbon source, glucose or olive oil, was investigated in vitro on the biomass produced by F. solani and on the degradation of benzo[a]pyrene (BaP) in mineral medium. After only 12 days of incubation, BaP degradation by F. solani was higher (37.4%) with olive oil used as the carbon source than the one obtained with glucose (4.2%). Catalase activity increased in the presence of olive oil (3.4 μkat mg⁻¹ protein) in comparison with glucose (2.1 μkat mg⁻¹ protein). When olive oil was used as the carbon source, BaP degradation increased up to 76.0% in the presence of a specific catalase inhibitor, 3-Amino-1,2,4-triazole (2 mM). This metabolic engineering strategy based both on the use of olive oil as carbon source (cultivation strategy) and on the blocking of the catalase activity could be an innovative and promising approach for fungal biodegradation of BaP and consequently for bioremediation of soil contaminated with polycyclic aromatic hydrocarbons.
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