scholarly journals Determination of Biocontrol Potential of Bacillus spp. and Stenotrophomonas sp. against Macrophomina phaseolina in Sunflower

Author(s):  
Özden Salman ◽  
Raziye Koçak ◽  
Nuh Boyraz

Macrophomina phaseolina is a soil pathogen known as charcoal rot and can cause up to 90% yield loss in sunflower under suitable conditions. The serious damage caused by chemicals used in the control of soil-borne pathogens to the environment and health has become one of the most important concerns in agriculture. Therefore, in our study, it was aimed to determine the in vitro antagonistic effects of various bacterial species against M phaseolina. A total of 38 bacterial strains were isolated from soil samples in the rhizosphere of Malva sylvestris (hibiscus), Vicia sativa (vetch), Cicer arietinum (chickpea), Papaver rhoeas (weasel), Carlina marianum (thistle), Glebionis coronaria (crown daisy) and Vicia faba collected from Urla district of İzmir. All bacterial strains exhibited antibiosis effect under in vitro conditions, but it was determined that 5 bacterial isolates among them showed a high inhibition zone and showed an average inhibition potential ranging between 55% and 74%. The most effective bacteria identified at species and genus level by Maldi biotyping (MALDI-TOF MS) were identified as Bacillus amyloliquefaciens, Stenotrophomonas sp. and Bacillus cereus (3 isolates), and these species showed that they can be important biocontrol agents in biological control against M. phaseolina.

2017 ◽  
Vol 28 (1) ◽  
pp. 70
Author(s):  
Ashraf S. Hassan

The antibacterial effect of citrus peel lemon against the bacterial strains obtained from the filters of air conditioners have been selected based on the presence most in these filters such as Streptococcus, Bacillus spp, Pseudomonas, E coli. agar well diffusion method used to evaluate antibacterial activity of citrus peels water extract. through the results became clear to us that the cold aqueous extract of lemon peel showed a significant effect on the growth of bacterial species through the diameters of inhibition zone that appeared in all concentrations of the extract (125, 250, 500, 1000) mg/ml. Gram-positive bacteria Streptococcus spp were the most affected Where the diameters of inhibition zone (18, 15, 12, 0, 0) mm respectively, while The Gram-negative bacteria E coli least affected. The results obtained in this study indicate that citrus lemon peel can be used in the treatment of diseases caused by organisms for the purposes of the pharmaceutical.


2008 ◽  
Vol 54 (6) ◽  
pp. 501-508 ◽  
Author(s):  
Karina Cogo ◽  
Michelle Franz Montan ◽  
Cristiane de Cássia Bergamaschi ◽  
Eduardo D. Andrade ◽  
Pedro Luiz Rosalen ◽  
...  

The aim of this in vitro study was to evaluate the effects of nicotine, cotinine, and caffeine on the viability of some oral bacterial species. It also evaluated the ability of these bacteria to metabolize those substances. Single-species biofilms of Streptococcus gordonii , Porphyromonas gingivalis , or Fusobacterium nucleatum and dual-species biofilms of S. gordonii – F. nucleatum and F. nucleatum – P. gingivalis were grown on hydroxyapatite discs. Seven species were studied as planktonic cells, including Streptococcus oralis , Streptococcus mitis , Propionibacterium acnes , Actinomyces naeslundii , and the species mentioned above. The viability of planktonic cells and biofilms was analyzed by susceptibility tests and time-kill assays, respectively, against different concentrations of nicotine, cotinine, and caffeine. High-performance liquid chromatography was performed to quantify nicotine, cotinine, and caffeine concentrations in the culture media after the assays. Susceptibility tests and viability assays showed that nicotine, cotinine, and caffeine cannot reduce or stimulate bacterial growth. High-performance liquid chromatography results showed that nicotine, cotinine, and caffeine concentrations were not altered after bacteria exposure. These findings indicate that nicotine, cotinine, and caffeine, in the concentrations used, cannot affect significantly the growth of these oral bacterial strains. Moreover, these species do not seem to metabolize these substances.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4958
Author(s):  
Jessa Marie V. Makabenta ◽  
Jungmi Park ◽  
Cheng-Hsuan Li ◽  
Aritra Nath Chattopadhyay ◽  
Ahmed Nabawy ◽  
...  

Biofilm infections are a global public health threat, necessitating new treatment strategies. Biofilm formation also contributes to the development and spread of multidrug-resistant (MDR) bacterial strains. Biofilm-associated chronic infections typically involve colonization by more than one bacterial species. The co-existence of multiple species of bacteria in biofilms exacerbates therapeutic challenges and can render traditional antibiotics ineffective. Polymeric nanoparticles offer alternative antimicrobial approaches to antibiotics, owing to their tunable physico-chemical properties. Here, we report the efficacy of poly(oxanorborneneimide) (PONI)-based antimicrobial polymeric nanoparticles (PNPs) against multi-species bacterial biofilms. PNPs showed good dual-species biofilm penetration profiles as confirmed by confocal laser scanning microscopy. Broad-spectrum antimicrobial activity was observed, with reduction in both bacterial viability and overall biofilm mass. Further, PNPs displayed minimal fibroblast toxicity and high antimicrobial activity in an in vitro co-culture model comprising fibroblast cells and dual-species biofilms of Escherichia coli and Pseudomonas aeruginosa. This study highlights a potential clinical application of the presented polymeric platform.


2019 ◽  
Vol 2 (1) ◽  
pp. 19
Author(s):  
Murni Halim

A study was carried out to screen for phytochemical constituents and assess the antioxidant and antimicrobial activities of Senna alata and Senna tora leaf extracts. The leaves were first dried at room temperature and 50°C in an oven prior to solvent extraction using ethanol and methanol. The in-vitro qualitative assays showed that both S. alata and S. tora leaf extracts contained bioactive and secondary metabolites components such as tannins, steroids, saponin, terpenoids, glycosides, flavonoids and phenols. The antioxidant activity and capacity test were carried out by conducting free radical of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and Ferric reduction antioxidant plasma (FRAP) assays. Both assays showed S. tora leaf extract has higher antioxidant capacity than S. alata leaf extract. The efficacy of these leaf extracts were tested against skin pathogens through agar well diffusion method. S. alata extract showed an inhibition zone (1.15 – 1.59 mm) against Pseudomonas aeruginosa while S. tora extracts exhibited a strong antimicrobial activity against S. epidermidis (inhibition zone of 12 – 16.94 mm) followed by P. aeruginosa (inhibition zone of 1 – 1.59 mm). Nonetheless, no inhibition zone was observed for S. aureus by both leaf extracts. The phytochemicals and antioxidant constituents as well as inhibitory potential on skin pathogens possessed by S. alata and S. tora leave highlighted their potential utilization in the development of natural drugs or cosmetics to treat skin related diseases or infections.


2021 ◽  
Vol 17 ◽  
Author(s):  
Lijuan Zhai ◽  
Lili He ◽  
Yuanbai Liu ◽  
Ko Ko Myo ◽  
Zafar Iqbal ◽  
...  

Background: Mononcyclic β-lactams are regarded as the most resistant class of β-lactams against a series of β-lactamases though possess limited antibacterial activity. Aztreonam being the first clinically approved monobactam needs broad-spectrum efficacy through structural modification. Objective: We strive to synthesize a number of monocyclic β-lactams by varying the substituents at N1, C3 and C4 positions of azetidinone ring and study the antimicrobial effect on variable bacterial strains. Methods: Seven new monobactam derivatives 23a-g, containing substituted-amidine moieties linked to the azetidinone ring via thiazole linker, were synthesized through multistep synthesis. The final compounds were investigated for their in vitro antibacterial activities using broth microdilution method, against ten bacterial strains of clinical interest. The minimum inhibitory concentrations (MICs) of newly synthesized derivatives were compared with aztreonam, ceftazidime and meropenem, existing clinical antibiotics. Results: All compounds 23a-g showed higher antibacterial activities (MIC 0.25 µg/mL to 64 µg/mL) against tested strains as compared to aztreonam (MIC 16 µg/mL to >64 µg/mL) and ceftazidime (MIC >64 µg/mL). However all compounds, except 23d, exhibited lower antibacterial activity against all tested bacterial strains as compared to meropenem. Conclusion: Compound 23d showed comparable or improved antibacterial activity (MIC 0.25 µg/mL to 2 µg/mL) to meropenem (MIC 1 µg/mL to 2 µg/mL) in case of seven bacterial species. Therefore, compound 23d may be valuable lead target for further investigations against multi-drug resistant Gram-negative bacteria.


2021 ◽  
Vol 12 (5) ◽  
pp. 523-531
Author(s):  
Anjali Singh ◽  
◽  
Ratna U. Thosar ◽  
Vijayshree Chavan ◽  
Sujoy Saha ◽  
...  

In vitro bio-efficacy of the novel copper (NC101 and NCP102) and phosphonate (PN103 and PMN104) based fungicides against various soil borne and grape vine pathogens was evaluated at ICAR-National Research Centre for Grapes, Pune, Maharashtra, India during February - April 2021. The fungicides were screened against five bacterial pathogens viz. Xanthomonas campestris pv. citri, X. campestris pv. campestris, X. campestris pv. punicae, X. campestris pv. viticola and X. oryzae pv. oryzae and 10 fungal pathogens viz. Rhizoctonia bataticola, Sclerotium rolfsii, Cladosporium sp, Alternaria alternata, Colletotrichum gloeosporioides, Penicillium notatum, Magnaporthe oryzae, Fusarium oxysporium, Macrophomina phaseolina (Soyabean isolate) and Macrophomina phaseolina (Jute isolate) at different concentrations. Results indicated that among all the tested fungicides viz. NC101, NCP102, PN103 and PMN104, phosphonate based fungicides (PN103 and PMN104) were highly effective against bacterial isolates with zone of inhibition ranging between 8.75 - 31.12 mm in which X. campestris pv. viticola was found to express least inhibition zone. In case of pathogenic fungal isolates, similar trend was observed, most of the isolates showed cent percent inhibition at higher concentration of PN103 and PMN104. However Sclerotium rolfsii showed least or no inhibition when tested at different concentrations of fungicides. The chemicals exhibited wide range of inhibition and it was found to increase steadily with increase in concentrations of the test fungicides.


2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Faisal GG ◽  
Zakaria SM ◽  
Najmuldeen GF

Introduction: Currently, researchers are aiming to explore herbal plants to replace synthetic drugs because herbal plants contain high active compounds and fewer side effects. Our study was done to determine the antibacterial activity of Eurycoma longifolia Jack (E. longifolia) root using ethanol based extract. Methods: Five types of pathogenic bacterial strains were used; Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa). Disc diffusion assay and Minimum Inhibitory Concentration (MIC) tests were used to determine the inhibition zone and turbidity of suspension which reflects the antibacterial activity of the extract. Results: The ethanolic extract of E. longifolia Jack root extract showed positive results against Gram-positive bacteria (S. aureus and B. cereus) and Gramnegative (S. typhi). B.cereus and S.typhi showed inhibition zone values of 11.76mm and 14.33mm at the extract concentration of 150mg/ml that were higher than the positive control values (9.00, 12.67mm) respectively. However, E. coli and P. aeruginosa did not show any inhibition by the ethanol-based extract. Conclusion: From the results we can conclude that E.Longifolia root extract possesses antibacterial activity that can be further explored to produce new medicinal products.


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.


2021 ◽  
Vol 17 ◽  
pp. 711-718
Author(s):  
Zafar Iqbal ◽  
Lijuan Zhai ◽  
Yuanyu Gao ◽  
Dong Tang ◽  
Xueqin Ma ◽  
...  

The diazabicyclooctane (DBO) scaffold is the backbone of non-β-lactam-based second generation β-lactamase inhibitors. As part of our efforts, we have synthesized a series of DBO derivatives A1–23 containing amidine substituents at the C2 position of the bicyclic ring. These compounds, alone and in combination with meropenem, were tested against ten bacterial strains for their antibacterial activity in vitro. All compounds did not show antibacterial activity when tested alone (MIC >64 mg/L), however, they exhibited a moderate inhibition activity in the presence of meropenem by lowering its MIC values. The compound A12 proved most potent among the other counterparts against all bacterial species with MIC from <0.125 mg/L to 2 mg/L, and is comparable to avibactam against both E. coli strains with a MIC value of <0.125 mg/L.


2019 ◽  
Vol 70 (4) ◽  
pp. 1496-1499
Author(s):  
Ioana Maria Carmen Ienascu ◽  
Diana Obistioiu ◽  
Iuliana Maria Popescu ◽  
Mariana Nela Stefanut ◽  
Osser Gyongyi ◽  
...  

In the dental office, disinfection and sterilization are a matter of utmost importance for both the physician, the medical staff and the patient. Twelve N-(2-bromo-phenyl)-2-hydroxy-benzamide and N-(4-bromo-phenyl)-2-hydroxy-benzamide derivatives were synthesized and tested for antimicrobial activity against 6 bacterial and 2 fungal strains using the Disk diffusion method for susceptibility testing. The obtained results indicated that the N-(2-bromo-phenyl)-2-hydroxy-benzamide derivatives were more active against the tested microbes, inhibition zones of 6-12 mm being obtained, although the most effective compound against S. pyogenes proved to be N-(4-bromo-phenyl)-2-hydroxy-benzamide (14 mm inhibition zone). The tested compounds presented no effect against S. aureus, S. flexneri, S. typhimurium and C. parapsilopsis at the tested concentration.


Sign in / Sign up

Export Citation Format

Share Document