scholarly journals Endophytic bacteria isolated from Leptospermum scoparium produce compounds that inhibit Ilyonectria and Neofusicoccum species in vitro

2015 ◽  
Vol 68 ◽  
pp. 445-445
Author(s):  
W.A. Wicaksono ◽  
E.E. Jones ◽  
J. Monk ◽  
H.J. Ridgway

Leptospermum scoparium JRForst et GForst var scoparium or m257;nuka is a New Zealand indigenous shrub This shrub is valued for the essential oil and medicinal honey it produces that have antimicrobial properties International research has demonstrated that endophytic bacteria can either directly produce or modify metabolites in planta Therefore bacteria within the m257;nuka endomicrobiome may also produce antimicrobial compounds A total of 192 endophytic bacteria were recovered from surface sterilised leaf stem and root tissue from three different sites These bacteria were assessed in dual culture assays against the grapevine pathogens Ilyonectria spp and Neofusicoccum spp Eleven and three endophytic bacteria showed ability to inhibit I liriodendri and N luteum respectively These endophytic bacteria produced both diffusible and volatile compounds that inhibited the pathogens Isolate W4R11 inhibited the growth of Ilyonectria spp by 4164 after 7 days incubation Isolate W1R33 could inhibit the faster growing Neofusicoccum spp by 2053 after 3 days incubation Microscopy showed that diffusible compound produced by isolate I1R21 caused hyphae and spore abnormality of Ilyonectria spp This study indicated that m257;nuka can potentially provide a new source of microorganisms for use in sustainable agriculture

2015 ◽  
Vol 68 ◽  
pp. 444-444
Author(s):  
N. Purushotham ◽  
E.E. Jones ◽  
J. Monk ◽  
H.J. Ridgway

Medicinal plants are valued for the naturally bioactive compounds they produce International research has demonstrated that these plants contain endophytic microorganisms that through close interaction with the plants physiology contribute to the production of host metabolites either directly or via involvement in biochemical pathways Some endophytes can produce bioactive compounds that are either the same or similar to those originating from their host plants Pseudowintera colorata (horopito or NZ pepper tree) an endemic New Zealand plant used in traditional Maori medicine (rongo257;) is recognised for its antimicrobial properties The biologically active chemical constituent polygodial is used for treating candidiasis A total of 340 endophytic bacteria were recovered from surface sterilised horopito leaves stems and roots from nine sites across New Zealand; strains were assessed for their ability to inhibit the phytopathogens Neofusicoccum parvum N luteum Ilyonectria liriodendri Nectria galligena Pectobacterium atrosepticum and P brasiliensis using a dual culture assay Inhibition zones 1048726;3 mm were considered a positive result Out of the strains tested seven showed activity against all the phytopathogenic fungi tested and ten strains were active against at least three phytopathogens Future work will determine if any of the endophytic bacteria produce polygodial


2012 ◽  
Vol 11 (1) ◽  
pp. 102 ◽  
Author(s):  
Zied Zarai ◽  
Ines Chobba ◽  
Riadh Mansour ◽  
Ahmed Békir ◽  
Néji Gharsallah ◽  
...  

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6905 ◽  
Author(s):  
Elena Maria Colombo ◽  
Cristina Pizzatti ◽  
Andrea Kunova ◽  
Claudio Gardana ◽  
Marco Saracchi ◽  
...  

Biocontrol microorganisms are emerging as an effective alternative to pesticides. Ideally, biocontrol agents (BCAs) for the control of fungal plant pathogens should be selected by an in vitro method that is high-throughput and is predictive of in planta efficacy, possibly considering environmental factors, and the natural diversity of the pathogen. The purpose of our study was (1) to assess the effects ofFusariumstrain diversity (N= 5) and culture media (N= 6) on the identification of biological control activity ofStreptomycesstrains (N= 20) againstFusariumpathogens of wheat in vitro and (2) to verify the ability of our in vitro screening methods to simulate the activity in planta. Our results indicate that culture media,Fusariumstrain diversity, and their interactions affect the results of an in vitro selection by dual culture assay. The results obtained on the wheat-based culture media resulted in the highest correlation score (r= 0.5) with the in planta root rot (RR) inhibition, suggesting that this in vitro method was the best predictor of in planta performance of streptomycetes against Fusarium RR of wheat assessed as extension of the necrosis on the root. Contrarily, none of the in vitro plate assays using the media tested could appropriately predict the activity of the streptomycetes against Fusarium foot rot symptoms estimated as the necrosis at the crown level. Considering overall data of correlation, the activity in planta cannot be effectively predicted by dual culture plate studies, therefore improved in vitro methods are needed to better mimic the activity of biocontrol strains in natural conditions. This work contributes to setting up laboratory standards for preliminary screening assays ofStreptomycesBCAs against fungal pathogens.


2021 ◽  
Vol 24 (1) ◽  
pp. 84-97
Author(s):  
Zohreh Karimi Taheri ◽  
◽  
Mohammad Hosein Aarabi ◽  
Ali Nazari Alam ◽  
Majid Nejati ◽  
...  

Background and Aim: Despite the anti-cancer and antimicrobial properties of licorice extract and lavender essential oil, some factors, such as low bioavailability and biodegradable, limit their therapeutic use. Using nanoparticles is a method to overcome these restrictions. This study aimed to investigate the anti-proliferative effects of nanoemulsion containing licorice extract and lavender essential oil on cancer cells; we also evaluated its antimicrobial properties in vitro. Methods & Materials: In this experimental study, nanoemulsions, containing licorice extract and lavender essential oil were developed by the spontaneous emulsion method. The anti-proliferative effect of nanoemulsion was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) colorimetric method on two cell lines HepG2 and SK-MEL-3. To measure the antimicrobial effect of 4 standard strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Minimum Inhibitory Concentration (MIC) method was used. Ethical Considerations: This study was approved by the Ethics Committee of Kashan University of Medical Sciences (Code: IR.KAUMS.MEDNT.REC.1396.106). Results: The results of MTT test on HepG2 cells indicated that the concentrations of 630, 1250, and 2500 μg/mL nanoemulsions caused toxicity to the cell and led to the death of >50% of the cells (IC50=401μg/mL; P<0.05). Evaluating SK-MEL3 cells revealed that except for 75 μg of nanoemulsion, other concentrations induced death in >50% of the cells (IC50 = 82 μg/mL; P<0.05). In addition, nanoemulsions, with antimicrobial properties, were studied in 4 strains of bacteria; the highest antimicrobial properties were observed in Staphylococcus epidermidis. Conclusion: Nanoemulsion containing licorice extract and lavender essential oil presents antimicrobial and antiproliferative effects on the two cell lines studied. The current study results indicated that the nano emulsification of lavender essential oil and licorice extract can enhance their biological impact; thus, they can be used as a drug formulation.


2020 ◽  
Vol 14 (2) ◽  
pp. 178-186
Author(s):  
Lisa Novita Arios ◽  
Dwi Suryanto . ◽  
Kiki Nurtjahja . ◽  
Erman Munir .

Assay on ability of endophytic bacteria isolated from peanut to inhibit Sclerotium sp. growth in peanut seedlings.   A study on assay of ability of endophytic bacteria to inhibit Sclerotium sp. in peanut seedling has been done. The bacteria were isolated from peanut healthy plants, while Sclerotium sp. was isolated from infected peanaut plant. Antagonistic assay was conducted by dual culture method.  In vivo assay of inhibiting Sclerotium sp. was conducted by dipping peanut seed in bacterial solution, and planting the seed in soil:compost (3:1) growing media. Six endophytic bacterial isolates showed to inhibit the growth of Sclerotium sp. in vitro. LN1 seemed to inhibit more of Sclerotium sp., while LN5 showed to inhibit less. Two potential isolates LN1 of gram-negative and LN2 of gram-positive using for further study showed to decrease more of dumping off. It also seemed that the isolates increased the seedling height, number of leaves, and dry weight.


2021 ◽  
Vol 24 (2) ◽  
pp. 107-120
Author(s):  
SMN Islam ◽  
SS Siddique ◽  
MZH Chowdhury ◽  
NJ Mishu

A native Trichoderma isolate was collected from the agricultural soil of Gazipur. This isolate was identified as a Trichoderma asperellum through morphology and analysis of internal transcribed spacer (ITS) region of ribosomal RNA gene sequence and reconstruction of the phylogenetic tree. The antagonistic effects of the newly identified T. asperellum isolate were assessed against brinjal bacterial wilt caused by Ralstonia solanacearum both in vitro and in planta. Both qualitative and quantitative bioassays were conducted in vitro. For qualitative tests, dual culture and antibacterial activity were carried out, and pathogen growth was observed visually. The antagonism of T. asperellum cell free culture filtrate on the growth of R. solanacearum was conducted in a quantitative test. Successful antagonism was recorded after both in vitro qualitative tests. In addition, the lowest colony forming unit was recorded in 100% of CFC (2.4±0.51 ×103 cfu/ml) in quantitative test. The T. asperellum inoculated plant showed low disease incidence (13.33%) when seedlings were challenged with R. solanacearum in planta experiment. Disease incidence was 100% for seedlings when treated with only R. solanacearum. The results showed that the isolated and identified T. asperellum isolate suppressed R. solanacearum growth in vitro and protected the seedling from wilting in planta. Therefore, this isolate could be considered as a potential isolate. Ann. Bangladesh Agric. (2020) 24(2) : 107-120


Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2223 ◽  
Author(s):  
Elaine Pereira dos Santos ◽  
Pedro Henrique Medeiros Nicácio ◽  
Francivandi Coêlho Barbosa ◽  
Henrique Nunes da Silva ◽  
André Luís Simões Andrade ◽  
...  

Film-forming emulsions and films, prepared by incorporating different concentrations of clove essential oil (CEO) and melaleuca essential oil (MEO) into chitosan (CS) were obtained and their properties were evaluated. Film-forming emulsions were characterized in terms of qualitative assessment, hydrogen potential and in vitro antibacterial activity, that was carried by the agar diffusion method, and the growth inhibition effects were tested on the Gram-positive microorganism of Staphylococcus aureus, Gram-negative microorganisms of Escherichia coli, and against isolated fungi such as Candida albicans. In order to study the impact of the incorporation of CEO and MEO into the CS matrix, the appearance and thickness of the films were evaluated. Furthermore, Fourier transform infrared spectroscopy (FTIR), contact angle measurements, a swelling test, scanning electron microscopy and a tensile test were carried out. Results showed that the film-forming emulsions had translucent aspect with cloudy milky appearance and showed antimicrobial properties. The CEO had the highest inhibition against the three strains studied. As regards the films’ properties, the coloration of the films was affected by the type and concentration of bioactive used. The chitosan/CEO films showed an intense yellowish coloration while the chitosan/MEO films presented a slightly yellowish coloration, but in general, all chitosan/EOs films presented good transparency in visible light besides flexibility, mechanical resistance when touched, smaller thicknesses than the dermis and higher wettability than chitosan films, in both distilled water and phosphate-buffered saline (PBS). The interactions between the chitosan and EOs were confirmed by. The chitosan/EOs films presented morphologies with rough appearance and with EOs droplets in varying shapes and sizes, well distributed along the surface of the films, and the tensile properties were compatible to be applied as wound dressings. These results revealed that the CEO and MEO have a good potential to be incorporated into chitosan to make films for wound-healing applications.


2012 ◽  
Vol 7 (7) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Samah Djeddi ◽  
Khadidja Djebile ◽  
Ghania Hadjbourega ◽  
Zoubida Achour ◽  
Catherine Argyropoulou ◽  
...  

The chemical composition of the essential oil obtained from the aerial parts of Santolina chamaecyparissus L., growing in Algeria, was investigated by GC-MS analyses. A total of 36 compounds were identified, accounting for 91.7% of the essential oil obtained. Camphor (31.1%) and cubenol (17.0%) were the predominant compounds. The potential of the antimicrobial activity was also investigated and the tested sample proved to be very active against Klebsiella pneumonia and Candida albicans (34.1 ± 0.02 mm and 35.0 ± 0.01 mm, respectively). Transverse sections of the leaf and stem of the plant suggest that the essential oil is localized in endogenous and exogenous sites.


2015 ◽  
Vol 15 (1) ◽  
pp. 72
Author(s):  
Susanti Tasik ◽  
Siti Muslimah Widyastuti ◽  
Harjono .

Mechanism of parasitism of Trichoderma harzianum on Fusarium oxysporum on Acacia mangium seedlings. Fusarium oxysporum is one of the most important soil-borne fungi the causal agent of damping-off disease. Detailed information it needed to know how the pathogen can be inhibited by Trichoderma harzianum. The objective of this research was to investigate the inhibition mechanism of T. harzianum on F. oxysporum in vitro and in planta. Green Flourescent Protein (GFP) T. harzianum was used as biocontrol agent of F. oxysporum. An in vitro inhibition test of T. harzianum was performed using dual culture method. In the in planta inhibition tests, seedlings of A. mangium were applied with GFP T. harzianum two days before inoculation of F. oxysporum; GFP T. harzianum was simultaneously applied with F. oxysporum and GFP T. harzianum was applied two days after inoculation of F. oxysporum. The inhibition effect of T. harzianum GFP was observed at seven days incubation, indicated by attachment of T. harzianum to F. oxysporum hyphae. GFP T. harzianum hyphae covered the colonies of F. oxysporum at 12 days after incubation. The highest life percentage of A. mangium seedlings was found on the treatment of GFP T. harzianum two days before inoculation of F. oxysporum (82.22%), whereas the lowest life percentage was found on seedling applied with GFP T. harzianum two days after inoculation of F. oxysporum (64.44%).


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