scholarly journals Antagonistic Activity of Bacillus spp. Against Fire Blight Disease In vitro and In planta

Author(s):  
Haris Butt ◽  
Kubilay Kurtulus Bastas

Fire blight, affecting more than one hundred and thirty species in the Rosaceae, is probably the most destructive disease affecting pear and apple cultivars in many countries. Currently, there are no effective synthetic compounds with systemic properties. Other major problem is the occurrence and spread of strains of Erwinia amylovora with resistance to streptomycin and copper. Taken into consideration the human and environmental health, the use of biocontrol agents either as an alternative or as a supplement within an integrated fire blight management strategy has attracted worldwide attention. In this study, E. amylovora solution of 107 CFU ml-1 was treated with bio-control agents, Bacillus subtilis str. QST 713, B. amyloliquefaciens str. MBI 600 and their mixture (at solution densities of 106, 107 and 108 CFU ml-1 for each one) on Petri dishes, containing King’s B medium and, compared with positive (streptomycin sulphate) and negative (sterile distilled water) controls. In vivo studies were performed on two-year-old apple cv. Gala seedlings grown in 45-cm-diameter pots containing a sterilized mix of soil–sand–peat under controlled greenhouse conditions (85% relative humidity, 25°C temperature and 16h of day light). The plants were irrigated as needed by drip-irrigation and each pot received a mineral solution (NPK: 20–20–20) at 2 g l-1 twice. When plant shoots reached a length of 30-35 cm, bio-control agents, individually and their mixture, were applied to the plants by a hand-sprayer. Obtaining the data, 108 CFU ml-1 of Bacillus spp. suspension mixture showed strongest in vitro antibacterial effect (26mm) among the tested treatments after positive control streptomycin (28.6mm). Parallel to in vitro findings, the mixture was most effective against the pathogen on cv. Gala (66.03%). Findings show that the use of mixture of beneficial microorganisms with individual antagonistic properties against the pathogen can be an effective strategy as a natural alternative to agrochemicals in the scope of good agriculture practices.

2008 ◽  
Vol 20 (9) ◽  
pp. 22
Author(s):  
T. J. Kaitu'u-Lino ◽  
D. J. Phillips ◽  
N. B. Morison ◽  
L. A. Salamonsen

10% of Australian women suffer from abnormal uterine bleeding (AUB). To stop endometrial bleeding after menstruation, the endometrium must repair adequately. We propose that endometrial restoration after menstruation has characteristics of wound healing and that inadequate endometrial repair may result in AUB. In vivo studies support a contribution of activins to skin wound healing: in mice overexpressing activins' natural inhibitor, follistatin, wound healing is significantly delayed (1). We hypothesised that activin would enhance endometrial repair and examined its contribution using an in vitro wound healing model and our well characterised in vivo mouse model of endometrial breakdown and repair (2). For the in vitro model, confluent human endometrial epithelial cells (ECC-1 cell line) were wounded and treated with carrier protein (control, 0.1% BSA), activin A (50ng/mL) or EGF (positive control: 50ng/mL). Wound areas were quantitated daily for 6 days. For the in vivo study, serum follistatin levels were measured by ELISA in follistatin overexpressing mice (FS) (2) and wild-type (WT) littermates. Mice were induced to undergo endometrial breakdown and repair (mimicking menstruation in women). Activin βA was immunolocalised during endometrial repair, and extent of repair assessed using our morphological scoring system (2). ECC-1 wound repair was significantly (P < 0.05) enhanced by activin A treatment v. control from days 2–6 of culture. In WT mice, activin βA localised to areas of endometrial repair. Serum follistatin was significantly elevated in FS mice v. controls (33.3 ± 3.8 v 7.07 ± 1.8 ng/mL, P < 0.01). In FS mice (n = 8) only 50% of uterine sections showed complete repair after endometrial breakdown, significantly less than those from WT animals (n = 15, P < 0.05) where 85% of sections demonstrated complete repair. These results demonstrate for the first time that activin A functions to promote endometrial restoration following menses and that this can be delayed under physiological conditions: such studies indicate potential treatments for AUB. (1) Wankell et al. (2001) EMBO J 20:5361–5372 (2) Kaitu'u-Lino et al. (2007) Endocrinology 148:5105–5111


Antibiotics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 432
Author(s):  
Kadmo Azevedo de Figueiredo ◽  
Helio Doyle Pereira da Silva ◽  
Stela Lima Farias Miranda ◽  
Francisco Jerfeson dos Santos Gonçalves ◽  
Arlene Pereira de Sousa ◽  
...  

This study investigated the effects of Brazilian Red Propolis (BRP) extract on seven-day-old multispecies subgingival biofilms. Mixed biofilm cultures containing 31 species associated with periodontal health or disease were grown for six days on a Calgary device. Then, mature biofilms were treated for 24 h with BRP extract at different concentrations (200–1600 µg/mL), amoxicillin (AMOXI) at 54 µg/mL (positive control) or vehicle (negative control). Biofilm metabolic activity was determined by colorimetry, and bacterial counts/proportions were determined by DNA–DNA hybridization. Data were analyzed by Kruskal–Wallis and Dunn’s tests. Treatment with BRP at 1600, 800 and 400 μg/mL reduced biofilm metabolic activity by 56%, 56% and 57%, respectively, as compared to 65% reduction obtained with AMOXI. Mean total cell counts were significantly reduced in all test groups (~50–55%). Lower proportions of red, green and yellow complex species were observed upon treatment with BRP (400 µg/mL) and AMOXI, but only AMOXI reduced the proportions of Actinomyces species. In conclusion, BRP extract was as effective as AMOXI in killing seven-day-old multispecies biofilm pathogens and did not affect the levels of the host-compatible Actinomyces species. These data suggest that BRP may be an alternative to AMOXI as an adjunct in periodontal therapy. In vivo studies are needed to validate these results.


Author(s):  
Kubilay Kurtulus Bastas

Erwinia amylovora, the causative agent of fire blight disease, threatens a lot of species of the Rosaceae family. Antibiotics and copper compounds in chemical applications are most frequently are applied, but these can be phytotoxic and cause resistant strains of the pathogen. In our experiments, 20 herbal materials were tested for their antimicrobial effectiveness against the fire blight pathogen in vitro and in planta. The air-dried plants ground into fine powder and extraction was performed at room temperature by maceration with 80% (v/v) methanol/distilled water. The minimum inhibitory concentration values were determined by using disc diffusion method and streptomycin was used as control in all experiments. Antimicrobial activity was evaluated by measuring the inhibition zones in reference to the pathogen. Among the tested plants, Szygium aromaticum, Thymus vulgaris and Rhus cararia showed a good antibacterial activity and they inhibited the growth of E. amylovora with inhibition zone diameter ranging from 21 to 27 mm at 20% (w/v) in absolute methanol compared to streptomycin (31 mm) in vitro conditions. In vivo tests were performed by using highly virulent E. amylovora isolate (Eak24b, 91%) grown on TSA medium and inoculation on young shoots of 3-year-old Gala variety of apple and Santa Maria variety of pear seedlings at 107 CFU ml-1 density of the pathogen. Disease severity (%) was assessed by by proportion of blighted shoot length to the whole shoot length and also efficacy of the extracts was determined by using Abbott formula. The highest efficacy was obtained by S. aromaticum and T. vulgaris extracts of reducing shoot blight of cv. Gala and cv. Santa Maria by 67.81% - 64-12% and 51.50% - 51.04% ratios, respectively. Obtaining results showed that some medicinal and aromatic plant extracts might be used against fire blight disease as potential new generation chemicals on pome fruits within integrated and organic control programs.


2021 ◽  
Vol 48 (3) ◽  
Author(s):  
Hind Lahmyed ◽  
◽  
Rachid Bouharroud ◽  
Redouan Qessaoui ◽  
Abdelhadi Ajerrar ◽  
...  

The present work aims to isolate actinomycete bacteria with antagonistic abilities towards Botrytis cinerea, the causal agent of gray mold, from a soil sample collected from the rhizosphere of a healthy tomato grove. In vitro confrontation led to the isolation of 104 actinomycete isolates; fifteen isolates have shown the most significant mortality rate of the mycelial growth of B. cinerea (>50%). Based on the results of this screening, representative strains were selected to verify their in vivo antagonistic activity on tomato fruits; the reduction of B. cinerea has a percentage ranging from 52.38% to 96.19%. Furthermore, the actinomycete isolates were evaluated for their plant growth-promoting (PGP) properties and their ability to produce biocontrol-related extracellular enzymes viz., amylase, protease, cellulase, chitinase, esterases, and lecithinase. Indeed, Ac70 showed high β-1,3-glucanase activity and siderophore production (17U/ml and 43% respectively), and the highest chitinase activity (39μmol/ml) was observed for Ac24. These results indicated that these actinomycetes might potentially control gray mold caused by B. cinerea on tomato fruits. Investigations on enhancing the efficacy and survival of the biocontrol agent in planta and finding out the best formulation are recommended for future research.


2019 ◽  
Author(s):  
Anita Kurilla ◽  
Timea Toth ◽  
Laszlo Dorgai ◽  
Zsuzsanna Darula ◽  
Tamas Lakatos ◽  
...  

AbstractTo attract pollinators many angiosperms secrete stigma exudate and nectar in their flowers. As these nutritious fluids are ideal infection points for pathogens, both secretions contain various antimicrobial compounds. Erwinia amylovora, the causing bacterium of the devastating fire blight apple disease, is the model pathogen that multiplies in flower secretions and infects through the nectaries. Although Erwinia resistant apples are not available, certain cultivars are tolerant. It was reported that in stigma infection assay, the ‘Freedom’ cultivar was Erwinia tolerant while the ‘Jonagold’ was susceptible. We hypothesized that differences in the nectar protein compositions lead to different susceptibility. Indeed we found that an acidic chitinase III protein (Machi3-1) selectively accumulates in the nectar and stigma of the ‘Freedom’ cultivar. We demonstrate that MYB binding site containing repeats of the ‘Freedom’ Machi3-1 promoter are responsible for the strong nectar- and stigma-specific expression. As we found that in vitro the Machi3-1 protein impairs growth and biofilm formation of Erwinia at physiological concentration, we propose that the Machi3-1 contribute to the tolerance by inhibiting Erwinia multiplication in the stigma exudate and in the nectar. We show that the Machi3-1 allele was introgressed from Malus floribunda 821 into different apple cultivars including the ‘Freedom’.HighlightCertain apple cultivars accumulate to high levels in their nectar and stigma an acidic chitinase III protein that can protect against pathogens including fire blight disease causing Erwinia amylovora


Author(s):  
Dian Ratih Laksmitawati ◽  
Rininta Firdaus ◽  
Mediana Astika Zein

Objectives: This study would like to investigate the in vitro antioxidant activity through 2,2-diphenyl-1-picrylhydrazyl assay and in vitro xanthine oxidase activity of the bulbs. This study performs in vivo assays to study the antihyperuricemic activity and antioxidant in the hyperuricemic rat through plasma malondialdehyde measurement. Method: The study was conducted by testing the fresh bulbs of bawang tiwai (Eleutherine palmifolia (L.) Merr. with chemical solvent of ethanol 70% to extract the bulbs. Allopurinol and Vitamin C were used as positive control for the antihyperuricemic assay and antioxidant assay, respectively. Other chemical substances were also used in this study. This study used chicken extract (Brands) 20 ml/kg/body weight to induce the level of uric acid in the blood serum, and potassium oxonate (Sigma 156124) to inhibit the uricase in rats. Results: The results show that the levels of uric acid were measured using spectrophotometer with dichloro-hydroxybenzen sulfonate (Biolabo) a as reagent. The ethanol extract of bawang tiwai (EBT) (E. palmifolia (L.) Merr) was potential to reduce uric acid level at 140, 280, and 560 mg/kg body weight, but possibly without inhibition against xanthine oxydase activity. Conclusion: All doses of EBT could inhibit lipid peroxidation in hyperuricemic condition caused by high purine diet in 14 days.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nidal Jaradat ◽  
Mohammed Hawash ◽  
Gada Dass

Abstract Background Rumex rothschildianus is the sole member of a unique section of the genus Rumex, in the family Polygonaceae. This species is a very rare small dioecious annual, endemic to Palestine that is traditionally used as food and for the treatment of various diseases. Therefore, the current investigation aimed to screen the chemical constituents, antioxidants, anti-α-amylase, anti-α-glucosidase, antilipase, and cytotoxic effects of four solvents fractions of R. rothschildianus leaves. Methods Dried powder of R. rothschildianus leaves was extracted in four solvents with different polarities. Several qualitative and quantitative phytochemical tests were performed to determine the components of the extracts. The colorimetric analysis was used for the quantitative determination of phenols, flavonoids, and tannins. In-vitro assays were performed to evaluate the extracts for antioxidant, anti-α-amylase, anti-α-glucosidase, and antilipase inhibitory activities, as well as cytotoxicity by MTS assay against cervical carcinoma cells line (HeLa) and breast cancer cell line (MCF7). Results The acetone fraction of R. rothschildianus leaves showed the most significant antioxidant activity, due to having the highest content of flavonoids and phenolics, with an IC50 value of 6.3 ± 0.4 μg/ml, compared to 3.1 ± 0.9 μg/ml for Trolox, and regarding lipase inhibition activity the acetone fraction showed the most potent activity with an IC50 value of 26.3 ± 0.6 μg/ml, in comparison with orlistat positive control IC50 12.3 μg/ml. The same extract was the most potent inhibitor of α-amylase and α-glucosidase, with IC50 values of 19.1 ± 0.7 μg/ml and 54.9 ± 0.3 μg/ml, respectively, compared to 28.8, 37.1 ± 0.3 μg/ml of acarbose, respectively. The hexane fraction showed 99.9% inhibition of HeLa cells and 97.4% inhibition for MCF7 cells. Conclusion The acetone fraction of R. rothschildianus leaves might provide a source of bioactive compounds for the treatment of oxidative stress. Similarly, the hexane fraction indicates the promising antitumor potential of R. rothschildianus. Clearly, these initial indications need further purification of potentially active compounds, and ultimately, in-vivo studies to determine their effectiveness.


2021 ◽  
Vol 37 ◽  
pp. e37089
Author(s):  
Mark Paul Selda Rivarez ◽  
Elizabeth P. Parac ◽  
Niño R. Laurel ◽  
Benjamin V. Cunanan ◽  
Angelie B. Magarro ◽  
...  

Anthracnose is a foliar and fruit disease caused by Colletotrichum spp. affecting a wide range of crops. Infection occurs early followed by quiescence in fruits, such as in banana, where chemical-based pesticides are used as a dependable fungal control for many years. There is an increasing need for a safe control and as implicated in the Organic Agriculture Act of 2010 (RA 10068) in the Philippines. This scenario drove the use of alternative pest control such as the use of biologicals and natural products. In this study, seven bacteria were isolated from wild honey, produced by Apis mellifera, wherein four (BC2, BC3, BC6 and BC7) were found to be an effective antagonist against Colletotrichum musae in in vitro conditions. These bacteria were identified to belong to the genus Lactobacillus spp. (BC2, BC3, BC7) and Bacillus spp. (BC6) based on sugar utilization tests, morphological and cultural growth in PDPA. For the in vivo test, different dilutions of wild honey were used and it was found out that lower concentrations were effective as biopesticide spray to prevent anthracnose infection. Lastly, we report herewith the first isolation of bacteria with biological control potential from wild honey, and to apply the raw or natural product as biopesticide in postharvest fruits.


2020 ◽  
Author(s):  
Serdar Durdagi

<p>Currently, the world suffers from a new coronavirus SARS-CoV-2 that causes COVID-19. Therefore, there is a need for the urgent development of novel drugs and vaccines for COVID-19. Since it can take years to develop new drugs against this disease, here we used a hybrid combined molecular modeling approach in virtual drug screening repurposing study to identify new compounds against this disease. One of the important SARS-CoV-2 targets namely type 2 transmembrane serine protease (TMPRSS2) was screened with NPC’s NIH small molecule library which includes approved drugs by FDA and compounds in clinical investigation. We used 6654 small molecules in molecular docking and top-50 docking scored compounds were initially used in short (10-ns) molecular dynamics (MD) simulations. Based on average MM/GBSA binding free energy results, long (100-ns) MD simulations were employed for the identified hits. Both binding energy results as well as crucial residues in ligand binding were also compared with a positive control TMPRSS2 inhibitor, Camostat mesylate. Based on these numerical calculations we proposed a compound (benzquercin) as strong TMPRSS2 inhibitor. If these results can be validated by in vitro and in vivo studies, benzquercin can be considered to be used as inhibitor of TMPRSS2 at the clinical studies.</p>


2019 ◽  
Vol 74 (11-12) ◽  
pp. 295-302
Author(s):  
Fulya Pak ◽  
Pinar Oztopcu-Vatan

Abstract This research investigated the antiproliferative effects of 1–500 μM fisetin in T98G and BEAS-2B cells by MTT assay. The IC50 of fisetin in T98G cells for 24 and 48 h were 93 and 75 μM, respectively. Apoptotic alterations of fisetin-treated T98G cells were observed by transmission electron microscopy. BEAS-2B was then used in comparison to T98G cells to determine the cytotoxic effects of fisetin. The IC50 of fisetin for 24 and 48 h were recorded as 270 and 90 μM in BEAS-2B cells, respectively. Different concentrations of fisetin were selected to determine the apoptotic and necrotic effects. Consequently, fisetin was determined to have more apoptotic effects in T98G than BEAS-2B cells, dose- and time-dependently. Moreover, fisetin was found to have cytotoxicity at lower doses in T98G cells compared to carmustine, as positive control. CASPASE 3, CASPASE 9, CASPASE 8, and BAX expressions were increased by the selected fisetin doses of 25 and 50 μM, while that of BCL-2 and survivin was reduced in T98G cells. These results will serve as an essential basis of future in vitro and in vivo studies, in the continuous search for alternative treatment agents for gliomas.


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