Screening, Identification, and Optimization of Fermentation Conditions of an Antagonistic Endophyte to Wheat Head Blight

Fusarium Head Blight (FHB, scab) is a destructive fungal disease that causes extensive yield and quality losses in wheat and other small cereals. Biological control of FHB is considered to be an alternative disease management strategy that is environmentally benign, durable, and compatible with other control measures. In this study, to screen antagonistic bacteria with the potential to manage FHB, 113 endophytes were isolated from the stems, leaves, panicles, and roots of wheat. Among them, six strains appeared to effectively inhibit Fusarium graminearum growth and one isolate, XS-2, showed a highly antagonistic effect against FHB. An in vitro antagonistic test of XS-2 on wheat heads confirmed that XS-2 could suppress the disease severity of FHB. The 16S rDNA sequence analysis revealed that XS-2 is a strain of Bacillus amyloliquefaciens. Antagonistic spectrum analyses showed that XS-2 had antagonistic effects against two and four types of cotton and fruit tree pathogens, respectively. The fermentation condition assays showed that glucose and peptone are the most suitable nutrient sources for XS-2, and that the optimal pH value and temperature for fermentation were 7.4 and 28 °C, respectively. Our study indicates that XS-2 has a good antagonistic effect on FHB and lays a theoretical foundation for the application of the strain as a biological agent in the field to control FHB.

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Intrapopulation Antagonism Can Reduce the Growth and Aggressiveness of the Wheat Head Blight Pathogen Fusarium graminearum

Phytopathology ◽

10.1094/phyto-09-19-0341-r ◽

2020 ◽

Vol 110 (4) ◽

pp. 916-926

Author(s):

Martha M. Vaughan ◽

Todd J. Ward ◽

Susan P. McCormick ◽

Nathane Orwig ◽

William T. Hay ◽

...

Keyword(s):

Fusarium Graminearum ◽

Management Practices ◽

Toxin Production ◽

Antagonistic Effect ◽

Head Blight ◽

Yield And Quality ◽

Pathogen Populations ◽

Moderately Resistant

Fusarium graminearum is a causal agent of Fusarium head blight (FHB), a disease that reduces yield and quality of cereal crops and contaminates grain with mycotoxins that pose health risks to humans and livestock. Interpopulation antagonistic interactions between isolates that produce different trichothecene mycotoxins can reduce FHB in wheat, but it is not known if interactions between isolates with a shared population identity that produce the same trichothecenes have a similar effect. Using isolates from the predominant F. graminearum populations in North America (NA1 and NA2), we examined intrapopulation interactions by comparing growth, disease progression, and toxin production of individual isolates with multi-isolate mixes. In vitro, mycelial growth was significantly greater when most NA1 and NA2 isolates were cultured individually versus when cultured as a mixture of isolates from the same population. In susceptible wheat Norm, FHB generally progressed faster in heads inoculated with an individual isolate versus a multi-isolate mixture, but the antagonistic effect of intrapopulation interactions was more pronounced for NA1 than NA2 isolates. By contrast, in moderately resistant wheat Alsen, mixtures of isolates from either population caused obvious reductions in FHB development. Mycotoxin contamination was not consistently affected by intrapopulation interactions and varied depending on the interacting isolates from either population. Our results indicate that antagonistic intrapopulation interactions can influence FHB in controlled environmental conditions. Understanding if the regional composition of pathogen populations similarly influences FHB in the field could improve disease forecasting and management practices.

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Effects of Weed Control in Established Alfalfa (Medicago sativa) on Forage Yield and Quality

Weed Science ◽

10.1017/s0043174500060562 ◽

1987 ◽

Vol 35 (4) ◽

pp. 564-567 ◽

Cited By ~ 11

Author(s):

Dennis R. Cosgrove ◽

Michael Barrett

Keyword(s):

Medicago Sativa ◽

Weed Control ◽

Stand Density ◽

Forage Yield ◽

Control Measures ◽

Acid Detergent Fiber ◽

Yield And Quality ◽

Herbicide Treatments ◽

Forage Yields

The effects of weed control measures in established alfalfa (Medicago sativaL.) on forage yield and quality were investigated at three sites with varying alfalfa densities and weed populations. Herbicide treatments were 0.56 and 1.12 kg/ha metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] applied in fall or spring, respectively, 1.68 kg/ha pronamide [3,5-dichloro (N-1,1-dimethyl-2-propynyl)benzamide] applied in fall, and combinations of these treatments. First-harvest forage yields (weeds plus alfalfa) were either reduced or unchanged by herbicide treatments. Total forage yield was not altered by the herbicide treatments, but first-harvest and total alfalfa yield as well as first-harvest forage protein content were increased by several treatments, depending on stand density and weed pressure. Little effect was observed on in vitro digestible dry matter or acid detergent fiber content.

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Endophytic bacteria isolated from a weed plant as a potential biocontrol agent against stem end rot pathogen of pitaya in Vietnam

Egyptian Journal of Biological Pest Control ◽

10.1186/s41938-021-00451-0 ◽

2021 ◽

Vol 31 (1) ◽

Author(s):

Do Quang Trung ◽

Luu The Anh ◽

Nguyen Thi Thuy ◽

Dinh Mai Van ◽

Tran Thi Hang

Keyword(s):

Endophytic Bacteria ◽

Inhibitory Effect ◽

Control Measures ◽

Economic Losses ◽

16S Rdna Sequence ◽

Eleusine Indica ◽

Disease Management Strategy ◽

Potential Biocontrol Agent

Abstract Background Stem end rot (SER) disease caused by Alternaria alternata is one of the main fungal diseases in pitaya and other crops in Nam Dinh, Vietnam, that leads to extensive yield and economic losses. Biocontrol of SER, using endophytic bacteria, is environmentally friendly and compatible with other control measures. Hence, it is emerging as an alternative disease management strategy in sustainable agriculture. This study aimed to screen antagonistic bacteria isolated from the weed, Eleusine indica, with the potential to manage SER. Results A total of 16 endophytes were isolated from the stems, leaves, and roots of the weed, E. indica. Of those, 6 strains presented antagonistic effects against A. alternata growth, and one isolate, EI-15, showed a significant inhibitory effect on SER. In addition, analyzing the 16S rDNA sequence indicated that EI-15 was a strain of Bacillus amyloliquefaciens. Moreover, the results of the antagonistic spectrum assay showed that EI-15 significantly inhibited some plant and fruit tree pathogens, especially the suppression of A. alternata. Notably, the culture filtrate of strain EI-15 exhibited in vitro apparent activity against A. alternata. Furthermore, an in vivo antagonistic experiment of EI-15 on pitaya twig showed a significant reduction of lesion on twigs than the control. Conclusions Overall, this study suggested the potential application of the EI-15 strain as a biological agent and needs to be further studied in the field to control SER.

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Hydrogen peroxide induced by the fungicide prothioconazole triggers deoxynivalenol (DON) production by Fusarium graminearum

Plant Breeding and Seed Science ◽

10.2478/v10129-011-0011-4 ◽

2011 ◽

Vol 63 (1) ◽

pp. 3-21 ◽

Cited By ~ 2

Author(s):

Kris Audenaert ◽

Elien Callewaert ◽

Monica Höfte ◽

Sarah De Saeger ◽

Geert Haesaert

Keyword(s):

Hydrogen Peroxide ◽

Fusarium Graminearum ◽

Point Of View ◽

Head Blight ◽

Fungal Genomics ◽

Yield And Quality ◽

Lethal Doses ◽

Important Disease

Hydrogen peroxide induced by the fungicide prothioconazole triggers deoxynivalenol (DON) production by Fusarium graminearum Fusarium head blight is a very important disease of small grain cereals with F. graminearum as one of the most important causal agents. It not only causes reduction in yield and quality but from a human and animal healthcare point of view, it produces mycotoxins such as deoxynivalenol (DON) which can accumulate to toxic levels. Little is known about external triggers influencing DON production. In the present work, a combined in vivo/in vitro approach was used to test the effect of sub lethal fungicide treatments on DON production. Using a dilution series of prothioconazole, azoxystrobin and prothioconazole + fluoxastrobin, we demonstrated that sub lethal doses of prothioconazole coincide with an increase in DON production 48 h after fungicide treatment. In an artificial infection trial using wheat plants, the in vitro results of increased DON levels upon sub lethal prothioconazole application were confirmed illustrating the significance of these results from a practical point of view. In addition, further in vitro experiments revealed a timely hyperinduction of H2O2 production as fast as 4h after amending cultures with prothioconazole. When applying H2O2 directly to germinating conidia, a similar induction of DON-production by F. graminearum was observed. The effect of sub lethal prothioconazole concentrations on DON production completely disappeared when applying catalase together with the fungicide. These cumulative results suggest that H2O2 induced by sub lethal doses of the triazole fungicide prothioconazole acts as a trigger of DON biosynthesis. In a broader framework, this work clearly shows that DON production by the plant pathogen F. graminearum is the result of the interaction of fungal genomics and external environmental triggers.

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Rhenium-188 Labeled Hydroxyapatite and Rhenium-188 Sulfur Colloid

Nuklearmedizin ◽

10.1055/s-0038-1629737 ◽

1997 ◽

Vol 36 (02) ◽

pp. 71-75 ◽

Cited By ~ 6

Author(s):

S. Glatz ◽

S. N. Reske ◽

K. G. Grillenberger

Keyword(s):

Synovial Fluid ◽

Ph Value ◽

Surgical Removal ◽

Radiation Synovectomy ◽

Sulfur Colloid ◽

Target Organs ◽

Aseptic Conditions ◽

In Vitro Stability ◽

Potential Use

Summary Aim: One therapeutic approach to rheumatoid arthritis and other inflammatory arthropathies besides surgical removal of inflamed synovium is radiation synovectomy using beta-emitting radionuclides to destroy the affected synovial tissue. Up to now the major problem associated with the use of labeled particles or colloids has been considerable leakage of radionuclides from the injected joint coupled with high radiation doses to liver and other non target organs. In this study we compared 188Re labeled hydroxyapatite particles and 188Re rhenium sulfur colloid for their potential use in radiation synovectomy. Methods: To this end we varied the labeling conditions (concentrations, pH-value, heating procedure) and analyzed the labeling yield, radiochemical purity, and in vitro stability of the resulting radiopharmaceutical. Results: After optimizing labeling conditions we achieved a labeling yield of more than 80% for 188Re hydroxyapatite and more than 90% for the rhenium sulfur colloid. Both of the radiopharmaceuticals can be prepared under aseptic conditions using an autoclav for heating without loss of activity. In vitro stability studies using various challenge solutions (water, normal saline, diluted synovial fluid) showed that 188Re labeled hydroxyapatite particles lost about 80% of their activity within 5 d in synovial fluid. Rhenium sulfur colloid on the other hand proved to be very stable with a remaining activity of more than 93% after 5 d in diluted synovial fluid. Conclusion: These in vitro results suggest that 188Re labeled rhenium sulfur colloid expects to be more suitable for therapeutic use in radiation synovectomy than the labeled hydroxyapatite particles.

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In vitro Lipolysis as a Tool for the Establishment of IVIVC for Lipid-Based Drug Delivery Systems

Current Drug Delivery ◽

10.2174/1567201816666190620115716 ◽

2019 ◽

Vol 16 (8) ◽

pp. 688-697

Author(s):

Ravinder Verma ◽

Deepak Kaushik

Keyword(s):

Drug Delivery ◽

Ph Value ◽

Electron Paramagnetic Resonance Spectroscopy ◽

Rapid Screening ◽

Resonance Spectroscopy ◽

Fed State ◽

In Vitro Lipolysis ◽

Ph Stat

: In vitro lipolysis has emerged as a powerful tool in the development of in vitro in vivo correlation for Lipid-based Drug Delivery System (LbDDS). In vitro lipolysis possesses the ability to mimic the assimilation of LbDDS in the human biological system. The digestion medium for in vitro lipolysis commonly contains an aqueous buffer media, bile salts, phospholipids and sodium chloride. The concentrations of these compounds are defined by the physiological conditions prevailing in the fasted or fed state. The pH of the medium is monitored by a pH-sensitive electrode connected to a computercontrolled pH-stat device capable of maintaining a predefined pH value via titration with sodium hydroxide. Copenhagen, Monash and Jerusalem are used as different models for in vitro lipolysis studies. The most common approach used in evaluating the kinetics of lipolysis of emulsion-based encapsulation systems is the pH-stat titration technique. This is widely used in both the nutritional and the pharmacological research fields as a rapid screening tool. Analytical tools for the assessment of in vitro lipolysis include HPLC, GC, HPTLC, SEM, Cryo TEM, Electron paramagnetic resonance spectroscopy, Raman spectroscopy and Nanoparticle Tracking Analysis (NTA) for the characterization of the lipids and colloidal phases after digestion of lipids. Various researches have been carried out for the establishment of IVIVC by using in vitro lipolysis models. The current publication also presents an updated review of various researches in the field of in vitro lipolysis.

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Improving Topical Skin Delivery of Monocrotaline Via Liposome Gel-based Nanosystems

Current Drug Delivery ◽

10.2174/1567201816666191029125300 ◽

2019 ◽

Vol 16 (10) ◽

pp. 940-950 ◽

Cited By ~ 1

Author(s):

Jiandong Yu ◽

Zhi Chen ◽

Yan-zhi Yin ◽

Chaoyuan Tang ◽

Enying Hu ◽

...

Keyword(s):

Gradient Method ◽

Encapsulation Efficiency ◽

Ph Value ◽

Topical Administration ◽

Ph Gradient ◽

Stability Factor ◽

Buffer Solution ◽

Skin Delivery ◽

Skin Retention

Background: In this study, a liposomal gel based on a pH-gradient method was used to increase the skin-layer retention of monocrotaline (MCT) for topical administration. Methods: Using the Box-Behnken design, different formulations were designed to form liposome suspensions with optimal encapsulation efficiency (EE%) and stability factor (KE). In order to keep MCT in liposomes and accumulate in skin slowly and selectively, MCT liposome suspensions were engineered into gels. Results: A pH-gradient method was used to prepare liposome suspensions. The optimal formulation of liposome suspensions (encapsulation efficiency: 83.10 ± 0.21%) was as follows: MCT 12 mg, soybean phosphatidyl choline (sbPC) 200 mg, cholesterol (CH) 41 mg, vitamin E (VE) 5 mg, and citric acid buffer solution (CBS) 4.0 10 mL (pH 7.0). The final formulation of liposomal gels consisted of 32 mL liposome suspensions, 4.76 mL deionized water, 0.40 g Carbopol-940, 1.6 g glycerol, 0.04 g methylparaben, and a suitable amount of triethanolamine for pH value adjustment. The results of in vitro drug release showed that MCT in liposomal gels could be released in 12 h constantly in physiological saline as a Ritger-Peppas model. Compared with plain MCT in gel form, liposomal MCT in gel had higher skin retention in vitro. Conclusion: In this study, liposomal gels were formed for greater skin retention of MCT. It is potentially beneficial for reducing toxicities of MCT by topical administration with liposomal gel.

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Photocuring Hyaluronic Acid/Silk Fibroin Hydrogel Containing Curcumin Loaded CHITOSAN Nanoparticles for the Treatment of MG-63 Cells and ME3T3-E1 Cells

Polymers ◽

10.3390/polym13142302 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2302

Author(s):

Qingwen Yu ◽

Zhiyuan Meng ◽

Yichao Liu ◽

Zehao Li ◽

Xing Sun ◽

...

Keyword(s):

Hyaluronic Acid ◽

Bone Regeneration ◽

Water Uptake ◽

Silk Fibroin ◽

Bone Repair ◽

Ph Value ◽

Chitosan Nanoparticles ◽

Vitro Assay ◽

Long Term Treatment

After an osteosarcoma excision, recurrence and bone defects are significant challenges for clinicians. In this study, the curcumin (Cur) loaded chitosan (CS) nanoparticles (CCNP) encapsulated silk fibroin (SF)/hyaluronic acid esterified by methacrylate (HAMA) (CCNPs-SF/HAMA) hydrogel for the osteosarcoma therapy and bone regeneration was developed by photocuring and ethanol treatment. The micro or nanofibers networks were observed in the CCNPs-SF/HAMA hydrogel. The FTIR results demonstrated that alcohol vapor treatment caused an increase in β-sheets of SF, resulting in the high compression stress and Young’s modulus of CCNPs-SF/HAMA hydrogel. According to the water uptake analysis, SF caused a slight decrease in water uptake of CCNPs-SF/HAMA hydrogel while CCNPs could enhance the water uptake of it. The swelling kinetic results showed that both the CCNPs and the SF increased the swelling ratio of CCNPs-SF/HAMA hydrogel. The accumulative release profile of CCNPs-SF/HAMA hydrogel showed that the release of Cur from CCNPs-SF/HAMA hydrogel was accelerated when pH value was decreased from 7.4 to 5.5. Besides, compared with CCNPs, the CCNPs-SF/HAMA hydrogel had a more sustainable drug release, which was beneficial for the long-term treatment of osteosarcoma. In vitro assay results indicated that CCNPs-SF/HAMA hydrogel with equivalent Cur concentration of 150 μg/mL possessed both the effect of anti-cancer and promoting the proliferation of osteoblasts. These results suggest that CCNPs-SF/HAMA hydrogel with superior physical properties and the bifunctional osteosarcoma therapy and bone repair may be an excellent candidate for local cancer therapy and bone regeneration.

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Mutual influence of selenium nanoparticles and FGF2-STAB® on biocompatible properties of collagen/chitosan 3D scaffolds: in vitro and ex ovo evaluation

Journal of Nanobiotechnology ◽

10.1186/s12951-021-00849-w ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Johana Muchová ◽

Vanessa Hearnden ◽

Lenka Michlovská ◽

Lucie Vištejnová ◽

Anna Zavaďáková ◽

...

Keyword(s):

Antibacterial Activity ◽

Metabolic Activity ◽

Mutual Influence ◽

Chorioallantoic Membrane ◽

Antagonistic Effect ◽

Dermal Fibroblasts ◽

Selenium Nanoparticles ◽

Freeze Dried ◽

Chitosan Scaffolds

AbstractIn a biological system, nanoparticles (NPs) may interact with biomolecules. Specifically, the adsorption of proteins on the nanoparticle surface may influence both the nanoparticles' and proteins' overall bio-reactivity. Nevertheless, our knowledge of the biocompatibility and risk of exposure to nanomaterials is limited. Here, in vitro and ex ovo biocompatibility of naturally based crosslinked freeze-dried 3D porous collagen/chitosan scaffolds, modified with thermostable fibroblast growth factor 2 (FGF2-STAB®), to enhance healing and selenium nanoparticles (SeNPs) to provide antibacterial activity, were evaluated. Biocompatibility and cytotoxicity were tested in vitro using normal human dermal fibroblasts (NHDF) with scaffolds and SeNPs and FGF2-STAB® solutions. Metabolic activity assays indicated an antagonistic effect of SeNPs and FGF2-STAB® at high concentrations of SeNPs. The half-maximal inhibitory concentration (IC50) of SeNPs for NHDF was 18.9 µg/ml and IC80 was 5.6 µg/ml. The angiogenic properties of the scaffolds were monitored ex ovo using a chick chorioallantoic membrane (CAM) assay and the cytotoxicity of SeNPs over IC80 value was confirmed. Furthermore, the positive effect of FGF2-STAB® at very low concentrations (0.01 µg/ml) on NHDF metabolic activity was observed. Based on detailed in vitro testing, the optimal concentrations of additives in the scaffolds were determined, specifically 1 µg/ml of FGF2-STAB® and 1 µg/ml of SeNPs. The scaffolds were further subjected to antimicrobial tests, where an increase in selenium concentration in the collagen/chitosan scaffolds increased the antibacterial activity. This work highlights the antimicrobial ability and biocompatibility of newly developed crosslinked collagen/chitosan scaffolds involving FGF2-STAB® and SeNPs. Moreover, we suggest that these sponges could be used as scaffolds for growing cells in systems with low mechanical loading in tissue engineering, especially in dermis replacement, where neovascularization is a crucial parameter for successful skin regeneration. Due to their antimicrobial properties, these scaffolds are also highly promising for tissue replacement requiring the prevention of infection.

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Using Commercial Compost as Control Measures against Cucumber Root-Rot Disease

Journal of Mycology ◽

10.1155/2013/324570 ◽

2013 ◽

Vol 2013 ◽

pp. 1-13 ◽

Cited By ~ 7

Author(s):

Kamel Kamal Sabet ◽

Magdy Mohamed Saber ◽

Mohamed Adel-Aziz El-Naggar ◽

Nehal Samy El-Mougy ◽

Hatem Mohamed El-Deeb ◽

...

Keyword(s):

Root Rot ◽

Control Measure ◽

Disease Incidence ◽

Pathogenic Fungi ◽

Pythium Ultimum ◽

Control Measures ◽

Infested Soil ◽

Fungal Isolates ◽

Cucumber Root

Five commercial composts were evaluated to suppress the root-rot pathogens (Fusarium solani (Mart.) App. and Wr, Pythium ultimum Trow, Rhizoctonia solani Kuhn, and Sclerotium rolfsii Sacc.) of cucumber plants under in vitro and greenhouse conditions. In vitro tests showed that all tested unautoclaved and unfiltrated composts water extracts (CWEs) had inhibitor effect against pathogenic fungi, compared to autoclaved and filtrated ones. Also, the inhibitor effects of 40 bacteria and 15 fungi isolated from composts were tested against the mycelial growth of cucumber root-rot pathogens. Twenty two bacteria and twelve fungal isolates had antagonistic effect against root-rot pathogens. The antagonistic fungal isolates were identified as 6 isolates belong to the genus Aspergillus spp., 5 isolates belong to the genus Penicillium spp. and one isolate belong to the genus Chaetomium spp. Under greenhouse conditions, the obtained results in pot experiment using artificial infested soil with cucumber root-rot pathogens showed that the compost amended soil reduced the percentage of disease incidence, pathogenic fungi population, and improved the cucumber vegetative parameters as shoot length, root length, fresh weight, and dry weight. These results suggested that composts are consequently considered as control measure against cucumber root-rot pathogens.

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