scholarly journals Microbial Origin of Aquaponic Water Suppressiveness against Pythium aphanidermatum Lettuce Root Rot Disease

2020 ◽  
Vol 8 (11) ◽  
pp. 1683
Author(s):  
Gilles Stouvenakers ◽  
Sébastien Massart ◽  
Pierre Depireux ◽  
M. Haïssam Jijakli

Aquaponic systems are an integrated way to produce fish and plants together with mutual benefits. Fish provide nutrients to plants on the one side, and plant nutrients uptake allow water reuse for fish on the other side. In this kind of system, the use of phytosanitary treatments to control plant pathogens is sensitive because of the risk of toxicity for fish present in the same water loop, especially coupled aquaponics. Among plant pathogens, Pythium aphanidermatum is a most problematic microorganism due to the Oomycete’s capacity to produce mobile form of dispersion (zoospores) in the recirculated water. Therefore, this study aimed at elucidating the potential antagonistic capacity of aquaponic water against P. aphanidermatum diseases. It was shown that aquaponic water presented an inhibitory effect on P. aphanidermatum mycelial growth in in vitro conditions. The same result was observed when lettuce plants growing in aquaponic water were inoculated by the same plant pathogen. Aquaponic lettuce was then compared to lettuce grown in hydroponic water or complemented aquaponic water (aquaponic water plus mineral nutrients). The disease was suppressed in the presence of aquaponic water, contrary to lettuce grown in hydroponic water or complemented aquaponic water. Root microbiota were analyzed by 16S rDNA and ITS Illumina sequencing to determine the cause of this aquaponic suppressive action. It was determined that the diversity and the composition of the root microbiota were significantly correlated with the suppressive effect of aquaponic water. Several taxa identified by metabarcoding were suspected to be involved in this effect. Moreover, few of these microorganisms, at the genus level, are known to have an antagonistic effect against P. aphanidermatum. These innovative results indicate that aquaponic water could be an interesting and novel source of antagonistic agents adapted to control P. aphanidermatum diseases in soilless culture.

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 349
Author(s):  
Dominik Bleša ◽  
Pavel Matušinský ◽  
Romana Sedmíková ◽  
Milan Baláž

The use of biological control is becoming a common practice in plant production. One overlooked group of organisms potentially suitable for biological control are Rhizoctonia-like (Rh-like) fungi. Some of them are capable of forming endophytic associations with a large group of higher plants as well as mycorrhizal symbioses. Various benefits of endophytic associations were proved, including amelioration of devastating effects of pathogens such as Fusarium culmorum. The advantage of Rh-like endophytes over strictly biotrophic mycorrhizal organisms is the possibility of their cultivation on organic substrates, which makes their use more suitable for production. We focused on abilities of five Rh-like fungi isolated from orchid mycorrhizas, endophytic fungi Serendipita indica, Microdochium bolleyi and pathogenic Ceratobasidium cereale to inhibit the growth of pathogenic F. culmorum or Pyrenophora teres in vitro. We also analysed their suppressive effect on wheat infection by F. culmorum in a growth chamber, as well as an effect on barley under field conditions. Some of the Rh-like fungi affected the growth of plant pathogens in vitro, then the interaction with plants was tested. Beneficial effect was especially noted in the pot experiments, where wheat plants were negatively influenced by F. culmorum. Inoculation with S. indica caused higher dry shoot biomass in comparison to plants treated with fungicide. Prospective for future work are the effects of these endophytes on plant signalling pathways, factors affecting the level of colonization and surviving of infectious particles.


2010 ◽  
Vol 50 (1) ◽  
pp. 93-97 ◽  
Author(s):  

Effect of Fungal Metabolites and Amendments on Mycelial Growth ofRhizoctonia SolaniA shift towards organic farming suggests amalgamation of organic resources against soil borne plant pathogens. The influence of metabolites of most ubiquitousAspergillusspp., organic amendment extracts and their combined effect withTrichoderma virenswere evaluatedin vitroagainstRhizoctonia solani.The minimum (36.1 mm) growth was attained byR. solaniin co-culture withA. niger.The maximum (42.3 mm) inhibition of mycelial growth of the test organism was observed with culture filtrate ofA. ochraceousfollowed byA. niger, A. fumigatus, A. flavusandA. terreus.Among organic amendment extractants, castor cake exhibited an additive effect on the growth ofT. virens, however, the maximum (41.8 mm) suppressive effect onR. solaniwas observed with vermicompost. With the advance in time, the effect of organic amendment extracts increased markedly. Inhibition potential of culture filtrate mixturte ofA. niger+T. virensandA. ochraceous+T. virensagainstR. solaniwas significantly higher in comparison to the other combinations.


2020 ◽  
Vol 8 (10) ◽  
pp. 285-291
Author(s):  
Budy Rahmat ◽  
Dedi Natawijaya ◽  
Endang Surahman

Liquid smoke is known to contain compounds that can control plant disease pathogens. This study aims to produce wood-waste liquid smoke and determine its effectiveness as a fungicide on plant pathogens. This research was conducted in two experimental stages, namely: (i) in vitro test as a preliminary test of the effectiveness of teak waste liquid smoke at concentrations of 0, 0.5, 1, 1.5, 2, and 2.5%; and (ii) in vivo test was arranged in randomized block design consisting of seven levels of liquid smoke concentration, namely 0, 1, 2, 3, 4, 5, and 6%, each of which was repeated four times. The results showed that the pyrolysis of 1 kg of wood waste was produced with the proportions of liquid smoke, charcoal and tar, respectively: 312 mL, 31 g, 367 g and the uncondensed gases. Treatment of liquid smoke in the in vivo test showed that a concentration of 1 to 2.5% liquid smoke was able to suppress the growth of the pathogenic fungus Sclerotium rolfsii 100%. The treatment of liquid smoke in the in vivo test showed an effect on inhibition of the growth diameter of fungal colonies, suppressing the disease occurance, and suppressing the lesion diameter.


1967 ◽  
Vol 45 (2) ◽  
pp. 269-280 ◽  
Author(s):  
Bruce M. Carruthers

The random and directed motility of human leukocytes was studied in vitro. Motility was found not to be dependent upon glucose in the medium. 2-Deoxyglucose was found to inhibit all motility completely. Dinitrophenol had a minor suppressive effect on both random and directed motility. Puromycin at 10−3 M and actinomycin D at 10 μg/ml had a disproportionately great inhibitory effect on directed motility, when compared with minor inhibitory effects on random motility. Actinomycin D at 20 μg/ml and trypsin at 0.1 mg/ml were found to inhibit both types of motility almost completely. Segregation of starch from the field of leukocyte motility was found to abolish its chemotactic effect. Restoration of some chemotactic influence was seen if both starch and leukocytes were present in the segregated area.


2021 ◽  
Author(s):  
Vignesh Murthy ◽  
VedhaHari BodethalaNarayanan ◽  
MubarakAli Davoodbasha ◽  
MadhanShankar ShankarRamakrishanan

Abstract A novel strain of Bacillus isolated from rhizosphere has shown to be excellent biocontrol agents against various plant pathogens. In this study, a first report of a Bacillus strain NKMV-3 which effectively controlling Alternaria solani, which cause the Early Blight disease in tomato. Based on the cultural and molecular sequencing of 16S rRNA gene sequence, the identity of the strain was confirmed as Bacillus velezensis NKMV-3. The presence of the lipopeptide which are antibiotic synthesis genes namely Iturin C, Surfactin A, Fengycin B and D were confirmed through gene amplification. In addition, lipopetides was also confirmed through liquid chromatography. The extract showed inhibitory effect against A.solani in-vitro and detached tomato leaf assays. Bacillus velezensis strain NKMV-3 based formulations may provide an effective solution in controlling early blight disease in tomato and other crops.


2018 ◽  
Vol 33 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Svetlana Milijasevic-Marcic ◽  
Vesna Todorovic ◽  
Olja Stanojevic ◽  
Tanja Beric ◽  
Slavisa Stankovic ◽  
...  

In vitro antagonistic potential of eleven isolates of Bacillus spp. against two phytopathogenic bacteria and one fungus was tested in order to identify potential biocontrol agents in vegetable crops. The Bacillus spp. isolates demonstrated different levels of antagonistic effect against the tested pathogenic microorganisms. Data in the study proved Xanthomonas vesicatoria to be more sensitive to Bacillus spp. strains than Clavibacter michiganensis subsp. michiganensis. Ten B. subtilis strains induced growth inhibition of X. vesicatoria, while a strain of B. pumilus did not affect the growth of that bacterium. The largest inhibition zones against X. vesicatoria were induced by strains B-319, B-325 and B-358. The pathogenic strain C. michiganensis subsp. michiganensis was most inhibited by two B. subtilis strains (B-338 and B-348) with mean inhibition zone diameters of up to 20 mm. B. subtilis strain B-319 which was the best in inhibiting X. vesicatoria, showed the lowest inhibitory effect on C. michiganensis subsp. michiganensis. The largest growth inhibition percentage of Verticillium sp. (PGI approximately 70%) was induced by B. subtilis strains B-310 and B-322. The other B. subtilis strains showed PGI values ranging from 45% to 68%, while B. pumilus strain B-335 had the least antagonistic potential (PGI =34.43%) against the pathogen. This study identified at least one suitable biocontrol candidate, B. subtilis strain B-358, as effective in vitro against all three vegetable pathogens.


Author(s):  
William Halim Santoso ◽  
Momoko Ishida ◽  
Kosuke Nishi ◽  
Takuya Sugahara ◽  
Agus Budiawan Naro Putra

Allergy rhinitis (AR), as reported by the World Allergy Organization (WAO), is one of the highest prevalence allergies affecting 10-30% of all adults and up to 40% of children. In Indonesia, current evidence showed that the prevalence of AR is increasing. Averrhoa bilimbi Linn. fruit (AF), or locally known as belimbing wuluh, has been scientifically proven to treat many diseases due to the abundant of polyphenol content which was shown to have the potential to treat allergies. Therefore, this study was aimed to investigate the anti-allergy potential of AF in vitro. The anti-allergy effect of Averrhoa bilimbi Linn. fruit water extract (AFWE) was examined using RBL-2H3 cells. At first, the cytotoxicity effect of AFWE was determined by WST-8 assay. The release of β-hexosaminidase by RBL-2H3 cells was also measured to evaluate degranulation suppression activity of AFWE. Lastly, calcium assay was employed to investigate the intracellular calcium concentration ([Ca­2+]i). Results demonstrated that AFWE does not show any cytotoxicity at any given concentration. In addition, AFWE at 1.25 mg/mL showed sufficient inhibitory effect towards degranulation by RBL-2H3 cells. Moreover, the degranulation-suppressing activity of AFWE was resulted from the inhibition of calcium-dependent signaling pathways. Unfortunately, the properties of active substances from AFWE have not been investigated. To conclude, this study indicated that AFWE has potential as an alternative treatment for allergic diseases.


2021 ◽  
Vol 13 (5) ◽  
pp. 857-863
Author(s):  
Jingjing Chen ◽  
Cheng Kang

As an important drug for the treatment of cancer, cis-diamine dichloroplatinum (CDDP) has poor solubility and antagonistic effect when it is used as a chemotherapy agent alone, leading to the insufficient dose in actual administration. In order to solve the above problems, increase the targeting property of CDDP carrier and prolong the half-life period of CDDP’s sustained-release, it is necessary to design a magnetic nano-carrier for CDDP with magnetic targeting function to reduce the damage of CDDP to normal tissues in vivo and improve the therapeutic effect of cancer. Carboxymethyl chitosan (CMCS) is used to directly coat oleic acid (OA)-modified Fe3O4 nanoparticles (OA-Fe3O4 NPs) to create the nano-scale CMCS magnetic nanoparticles (CMCS/OA-Fe2O3 NPs), and CDDP loaded magnetic nanoparticles (CMCS/OA-Fe2O3 NPs/CDDP) are prepared by the bonding interaction between carboxyl groups on the surface of CMCS and the anticancer drug CDDP. The magnetic drug loaded nanoparticles are characterized, and the results show that the magnetic nanoparticles are successfully embedded in CMCS and loaded with CDDP, with the drug load of 43.65 ± 2.37%. MTT assay, flow cytometry and invasion assay are applied to evaluate the inhibitory effect of magnetic drug loaded nanoparticles to nasopharyngeal carcinoma (NPC) cells HNE-1. The results suggest that the magnetic drug loaded nanoparticles successfully prepared have significant inhibitory effect on HNE-1 cells in vitro. Therefore, the magnetic drug loaded nanoparticles prepared have a good therapeutic effect on NPC.


2020 ◽  
Vol 44 (5) ◽  
pp. 315-322
Author(s):  
Liz Mariana Hernández-Bautista ◽  
Raúl Márquez-Preciado ◽  
Marine Ortiz-Magdaleno ◽  
Amaury Pozos-Guillén ◽  
Saray Aranda-Romo ◽  
...  

Purpose: The objective was to evaluate the antagonistic effect of Lactobacillus and Bifidobacterium recovered from five commercial probiotics on the growth of C. albicans. Study design: The Lactobacillus and Bifidobacterium strains of five commercial probiotics were recovered and grown: Probio Hp+®, ProBiseis®, Lactipan®, Liolactil®, and Lacteol Fort®; 50 mg of each was hydrated and grown in Lactobacilli MRS (De Man, Rogosa and Sharpe) broth and incubated at 37°C with stirring (120 RPM) for 24 hours. Serial dilutions of 10−1 to 10−7 were made and viability was verified and quantified. For the antagonism tests, a suspension/inoculum of Lactobacillus strains recovered from each commercial preparation (4–30 × 109) and C. albicans ATCC 90028 (1.5–8 × 108) was prepared in MRS broth and incubated for 48 hours at 36°C, then plated on Dextrose Sabouraud Agar with Chloramphenicol and Rogosa Agar and the colony-forming units (CFU) were quantified. Additionally, viability was evaluated using the LIVE/DEAD® Yeast and Bacterial Viability kit. Results: The probiotic that produced the highest acidity of the medium was Lactipan®, followed by Probiseis® and Liolactil®, while Probio Hp+® showed the least change. Probiseis® was determined to have the highest growth of probiotic bacteria and the highest inhibition on C. albicans, followed by Lactipan®; Liolactil® and ProbioHp+® showed the least effect. In fluorescence tests, ProBiseis® showed the best effect, followed by Liolactil® and Lactipan®; Probio Hp+® had less of an effect. Conclusions: Two commercial products (ProBiseis and Lactipan) whose formulations have L. acidophilus, L. casei, L. rhamnosus, L. plantarum, B. infantis, and S. thermophilus have a greater inhibitory effect on C. albicans ATCC 90028


1988 ◽  
Vol 119 (2) ◽  
pp. 181-188 ◽  
Author(s):  
Doo Chol Han ◽  
Kanji Sato ◽  
Yuko Fujii ◽  
Minoru Ozawa ◽  
Hidehito Imamura ◽  
...  

Abstract. To elucidate the effect of rT3 on iodothyronine-5′-deiodinating activity (I-5′-DA) in the liver of neonatal mice, rT3 was injected sc on the 5–8th day after birth and I-5′-DA in the liver was determined. A single injection of rT3 (0.01–1 μg/g) inhibited the ontogenetically developing I-5′-DA in a dose- and time-dependent manner. The inhibitory effect was reversible and specific for I-5′-DA. Lineweaver-Burk analysis revealed that the time- and dose-dependent decrease in the enzyme activity was due to a decrease in Vmax with no alteration in Km values (5 × 10−8 mol/l). The maximal inhibitory effect was observed at a dose of 1 μg rT3/g, whereas the inhibitory effect was diminished at greater doses (4–10 μg/g), probably owing to a contamination with T4 of the rT3 preparation administered. Furthermore, consistent with our previous in vitro findings, rT3 inhibited the I-5′-DA induced by T3 in the liver of neonatal mice. These findings suggest that rT3 inhibited I-5′-DA in the liver of neonatal mice by decreasing the amount of enzyme available to the substrate and that rT3 also elicited an antagonistic effect against T3 in the induction of I-5′-DA in vivo.


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