Selection of phytotoxin producing rhizobacteria

In order to select phytotoxin producing rhizobacteria to control weed plants, twenty five bacterial strains previously isolated from the rhizospheres of various plants were grown in a liquid medium and, after cell removal by centrifugation, the liquid phases were freeze-dried and the products were extracted with ethyl acetate/methanol. The extracts were concentrated to dryness under vacuum and dissolved in water and sucrose solution to be submitted to in vitro assays of lettuce (Lactuca sativa L.) seed germination and wheat (Triticum aestivum L.) coleoptile growth. Although most samples affected coleoptile growth, only those from four strains reduced lettuce seed germination. Two strains of Bacillus cereus, one strain of B. pumilus and one of Stenotrophoonas altophilia were the most promising microorganisms for producing phytotoxin and, consequently, for the development of new weed control products.

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Repurposing of auranofin against bacterial infections: An In silico and In vitro study

Current Computer - Aided Drug Design ◽

10.2174/1386207323666200717155640 ◽

2020 ◽

Vol 16 ◽

Author(s):

Nidhi Sharma ◽

Arti Singh ◽

Ruchika Sharma ◽

Anoop Kumar

Keyword(s):

Broad Spectrum ◽

In Silico ◽

Antibacterial Agent ◽

Bacterial Infections ◽

In Vitro Assays ◽

Infection Model ◽

Synergistic Activity ◽

Bacterial Strains ◽

Molecular Docking Study

Aim: The aim of the study was to find out the role of auranofin as a promising broad spectrum antibacterial agent. Methods: In-vitro assays (Percentage growth retardation, Bacterial growth kinetics, Biofilm formation assay) and In-silico study (Molegro virtual docker (MVD) version 6.0 and Molecular operating environment (MOE) version 2008.10 software). Results: The in vitro assays have shown that auranofin has good antibacterial activity against Gram positive and Gram negative bacterial strains. Further, auranofin has shown synergistic activity in combination with ampicillin against S. aureus and B. subtilis whereas in combination with neomycin has just shown additive effect against E. coli, P. aeruginosa and B. pumilus. In vivo results have revealed that auranofin alone and in combination with standard drugs significantly decreased the bioburden in zebrafish infection model as compared to control. The molecular docking study have shown good interaction of auranofin with penicillin binding protein (2Y2M), topoisomerase (3TTZ), UDP-3-O-[3- hydroxymyristoyl] N-acetylglucosaminedeacetylase (3UHM), cell adhesion protein (4QRK), β-lactamase (5CTN) and arylsulphatase (1HDH) enzyme as that of reference ligand which indicate multimodal mechanism of action of auranofin. Finally, MTT assay has shown non-cytotoxic effect of auranofin. Conclusion: In conclusion, auranofin in combination with existing antibiotics could be developed as a broad spectrum antibacterial agent; however, further studies are required to confirm its safety and efficacy. This study provides possibility of use of auranofin apart from its established therapeutic indication in combination with existing antibiotics to tackle the problem of resistance.

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Characterization of Antibacterial Proanthocyanidins of Dalbergia monetaria, an Amazonian Medicinal Plant, by UHPLC-HRMS/MS

Planta Medica ◽

10.1055/a-1170-8016 ◽

2020 ◽

Vol 86 (12) ◽

pp. 858-866

Author(s):

Patricia Homobono Brito de Moura ◽

Amaryllis Almeida de Sousa ◽

Andrea Porzel ◽

Ludger A. Wessjohann ◽

Ivana Correa Ramos Leal ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Pathogenic Bacteria ◽

Neutral Loss ◽

Antibacterial Activities ◽

Quinone Methide ◽

In Vitro Assays ◽

Fragmentation Pattern ◽

Bacterial Strains ◽

Tract Infections

Abstract Dalbergia monetaria is an Amazonian plant whose bark is widely used to treat urinary tract infections. This paper describes a bio-guided study of ethanolic extracts from the bark and leaves of D. monetaria, in a search for metabolites active against human pathogenic bacteria. In vitro assays were performed against 10 bacterial strains, highlighting methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Fractioning of the extracts was performed using instrumental and classical techniques, and samples were characterized by UHPLC-HRMS/MS. Ethyl acetate fractions from bark and leaves showed similar antibacterial activities. EAFB is enriched in isoflavone C-glucosides and EAFL enriched in proanthocyanidins. Subfractions from EAFL presented higher activity and showed a complex profile of proanthocyanidins constructed by (epi)-cassiaflavan and (epi)-catechin units, including dimers, trimers and tetramers. The fragmentation pattern emphasized the neutral loss of cassiaflavan units by quinone-methide fission. Fraction SL7-6, constituted by (ent)-cassiaflavan-(ent)-cassiaflavan-(epi)-catechin isomers, showed the lowest MIC against the S. aureus and P. aeruginosa with values corresponding to 64 and 32 µg/mL, respectively. Cassiaflavan-proanthocyanidins have not been found previously in another botanical genus, except in Cassia, and the traditional medicinal use of D. monetaria might be related to the antibacterial activity of proanthocyanidins characterized in the species.

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Suppression of Fusarium moniliforme in Rice by Rice-Associated Antagonistic Bacteria

Plant Disease ◽

10.1094/pdis.1997.81.1.49 ◽

1997 ◽

Vol 81 (1) ◽

pp. 49-52 ◽

Cited By ~ 24

Author(s):

A. M. Rosales ◽

T. W. Mew

Keyword(s):

Seed Germination ◽

Fusarium Moniliforme ◽

Mycelial Growth ◽

Field Trials ◽

The Philippines ◽

The Other ◽

Antagonistic Bacteria ◽

Seedling Vigor ◽

Bacterial Strains

The potential of antagonistic bacteria from paddy water, rhizosphere soils, sclerotia, and rice plants to control “bakanae” caused by Fusarium moniliforme was assessed. Experiments were conducted to determine the in vitro antibiosis and effect of bacteria on seed germination. Out of 441 isolates, 113 were inhibitory to mycelial growth of the pathogen. Bacterial strains were classified into three groups based on effect on seed germination: (i) those that promoted germination and enhanced seedling vigor; (ii) those that had no effect on germination; and (iii) those that were deleterious and inhibited germination. Bacterization of naturally infected seeds reduced bakanae incidence in seedbox and seedbed tests. In a seedbed experiment with IR 58 seeds soaked in suspensions of bacterial strains, bakanae incidence and disease control ranged from 0.9 to 6.8% and 71.7 to 96.3%, respectively. From the 3 years of field trials, 10 strains reduced bakanae. Five strains consistently reduced bakanae, but the other five exhibited variable effects among trials. Specificity of suppression by antagonistic bacteria against different pathogenic isolates of F. moniliforme from various locations in the Philippines was observed.

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Exploring the Potential Soil Bacteria for Sustainable Wheat (Triticum aestivum L.) Production

10.20944/preprints201904.0234.v1 ◽

2019 ◽

Author(s):

Rizwan Sheirdil ◽

Rifat Hayat ◽

Xiao-Xia Zhang ◽

Nadeem Abbasi ◽

Safdar Ali ◽

...

Keyword(s):

Triticum Aestivum ◽

Plant Growth ◽

Triticum Aestivum L ◽

Growth And Yield ◽

Recommended Dose ◽

Bacterial Strains ◽

Chemical Fertilizers ◽

Inorganic Fertilizers

Plant growth promoting rhizobacteria (PGPR) are capable to reduce the use of chemical fertilizers input cost of farmer. Keeping in view the study was designed to investigate and evaluate inoculation effect of indigenous rhizospheric bacteria on growth and yield of wheat (Triticum aestivum L.) under in vitro and in vivo conditions using different treatments. Ten potential strains were selected on the basis of their ACC deaminase activity, siderophore production, P-solubilization and production of indole acetic acid (IAA). Further these strains were tested in three different experiments (growth chamber, pot and field). We found significant increase in crop growth response to the inoculants in comparison with un-inoculated control. In pot and field trial we tested PGPR with recommended dose of inorganic fertilizers. The results of present study revealed that inoculation of bacterial strains with wheat seeds significantly increased plant growth and improved crop yield. Results of present study reveal that these strains could be employed in different combinations and can get higher yield in case of half recommended doses of inorganic fertilizers along with consortium of strains in comparison with sole application of recommended dose of fertilizer and with consortium of strains. These strains were further identified by 16Sr RNA gene sequencing, fatty acid profile and biolog. It can be concluded that inoculated bacteria have more potential and contributes in good crop quality, increased yield when they are applied in combination, thus have potential to minimize use of chemical fertilizers.

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Lactococcosis a Re-Emerging Disease in Aquaculture: Disease Significant and Phytotherapy

Veterinary Sciences ◽

10.3390/vetsci8090181 ◽

2021 ◽

Vol 8 (9) ◽

pp. 181

Author(s):

Mehdi Soltani ◽

Bernardo Baldisserotto ◽

Seyed Pezhman Hosseini Shekarabi ◽

Shafigh Shafiei ◽

Masoumeh Bashiri

Keyword(s):

Antibacterial Activity ◽

Essential Oils ◽

Medicinal Herbs ◽

In Vitro Assays ◽

Bacterial Disease ◽

Bacterial Strains ◽

Immune Parameters ◽

Aquaculture Industry

Lactococcosis, particularly that caused by Lactococcus garvieae, is a major re-emerging bacterial disease seriously affecting the sustainability of aquaculture industry. Medicinal herbs and plants do not have very much in vitro antagonism and in vivo disease resistance towards lactococcosis agents in aquaculture. Most in vitro studies with herbal extractives were performed against L. garvieae with no strong antibacterial activity, but essential oils, especially those that contain thymol or carvacrol, are more effective. The differences exhibited by the bacteriostatic and bactericidal functions for a specific extractive in different studies could be due to different bacterial strains or parts of chemotypes of the same plant. Despite essential oils being shown to have the best anti-L. garvieae activity in in vitro assays, the in vivo bioassays required further study. The extracts tested under in vivo conditions presented moderate efficacy, causing a decrease in mortality in infected animals, probably because they improved immune parameters before challenging tests. This review addressed the efficacy of medicinal herbs to lactococcosis and discussed the presented gaps.

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Less Polar Compounds and Targeted Antioxidant Potential (In Vitro and In Vivo) of Codium adhaerens C. Agardh 1822

Pharmaceuticals ◽

10.3390/ph14090944 ◽

2021 ◽

Vol 14 (9) ◽

pp. 944

Author(s):

Sanja Radman ◽

Ana-Marija Cikoš ◽

Ivana Flanjak ◽

Sanja Babić ◽

Lara Čižmek ◽

...

Keyword(s):

High Resolution Mass Spectrometry ◽

Solid Phase ◽

Antioxidant Properties ◽

Polar Compounds ◽

Antioxidant Potential ◽

In Vitro Assays ◽

Pheophytin A ◽

Freeze Dried

Codium adhaerens from the Adriatic Sea (Croatia) was comprehensively investigated regarding less polar compounds for the first time. Although there are several phytochemical studies on C. adhaerens from other regions, this is the first report on volatile organic compounds (VOCs) from fresh (FrCa) and air-dried (DrCa) samples. The novelty is also related to its targeted antioxidant potential in vitro and in vivo. The main aims were to: (a) identify and compare VOCs of FrCa and DrCa obtained by headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD); (b) determine fatty acid (FA) composition of freeze-dried sample (FdCa); (c) determine the composition of less polar fractions of FdCa by high-performance liquid chromatography–high-resolution mass spectrometry with electrospray ionisation (UHPLC-ESI-HRMS); and (d) comprehensively evaluate the antioxidant activity of the fractions by four in vitro assays and in vivo zebrafish model (including embryotoxicity). Significant changes of VOCs were found after air drying. ω6 FAs were present in higher content than ω3 FAs indicating C. adhaerens as a good source of dietary polyunsaturated FAs. The results obtained in vivo correlate well with in vitro methods and both fractions exerted similar antioxidative responses which is in agreement with the high abundance of present biomolecules with known antioxidant properties (e.g., fucoxanthin, pheophytin a, and pheophorbide a). These results suggest that C. adhaerens might be a potent source of natural antioxidants that could be further used in the research of oxidative stress-related diseases.

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Allelopathic effect of aqueous extracts from agro-industrial residues of pecan nut [Carya illinoinensis (Wangenh) C. Koch] and pinhão (Araucaria angustifolia)

Revista Eletrônica Científica da UERGS ◽

10.21674/2448-0479.33.495-507 ◽

2017 ◽

Vol 3 (3) ◽

pp. 495-507 ◽

Cited By ~ 2

Author(s):

Voltaire SANT'ANNA ◽

Maico Ismael KLEIN ◽

Elaine BIONDO ◽

Eliane Maria KOLCHINSKI

Keyword(s):

Seed Germination ◽

Seed Coat ◽

Plant Root ◽

In Vitro Tests ◽

Allelopathic Effect ◽

Lettuce Seed ◽

Aqueous Extracts ◽

Industrial Residues ◽

Pecan Nutshell

Pinhão seed coat and pecan nutshell are residues widely produced in households and industries, which present great potential to be used as source of natural preservatives in the food chain. The objective of the present study is to evaluate the effectiveness of pinhão seed coat and pecan nutshell aqueous extracts in inhibiting seed germination. Extracts were obtained in concentration of 10g/L, 5g/L and 2.5g/L and tested against lettuce seed germination in vitro tests. The results show that both aqueous extract presented the significant (p<0.05) ability to inhibit seeds germination as well as the germination seed index, in relation to control experiments, when used in concentrations of up to 5g/L. Extracts did not interfere significantly (p>0.05) the germinated plant root size. Thus, aqueous extracts of agro-industrial residues from pinhão seed coat and pecan nutshell presents alellopathic activity, showing up as interesting alternative to be used as natural herbicide, also representing a way of solid waste management by industries and small farmers.

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In vitro Assessment of Bacterial Strains Associated with Microalgae as Potential Probiotics

Pertanika Journal of Tropical Agricultural Science ◽

10.47836/pjtas.44.1.12 ◽

2021 ◽

Vol 44 (1) ◽

Author(s):

Aimi Zabidi ◽

Natasya-Ain Rosland ◽

Jasmin Yaminudin ◽

Murni Karim

Keyword(s):

Antimicrobial Activity ◽

In Vitro Assays ◽

Disc Diffusion ◽

Bacterial Strains ◽

Pathogenic Vibrio ◽

Fish And Shellfish ◽

Diffusion Assay ◽

Vibrio Spp

Bacteria and microalgae are essential elements in the aquatic ecosystem, co-existing and having constant interactions with each other which help microalgae to exert its beneficial effect as probiotics in aquaculture. This research aims to isolate and identify potential probiotics from different species of microalgae and to evaluate their antimicrobial activity against pathogenic Vibrio spp. via series of in vitro assays; disc diffusion, well diffusion, and co-culture assays. A total of 18 bacterial strains were isolated from five species of microalgae; Chlorella sp., Nannochloropsis sp., Amphora sp., Chaetoceros sp., and Spirulina sp.. The isolated strains were tested in in vitro antagonistic assay against four Vibrio spp. (Vibrio harveyi, Vibrio alginolyticus, Vibrio vulnificus, and Vibrio parahaemolyticus). Seventeen strains demonstrated antimicrobial activity with the highest inhibition was observed by strain SPS11 against V. parahaemolyticus (12.6 ± 0.36 mm) in disc diffusion assay and strain NAS32 showed 13.2 ± 0.45 mm clear zone against V. vulnificus in well diffusion assay. In co-culture assay, both the SPS11 and NAS32 were able to reduce the growth of V. parahaemolyticus and V. harveyi at concentration of 106 and 108 CFU mL-1, respectively. Strains SPS11 and NAS32 were characterized as gram positive bacteria with rod shape and further identified as Lysinibacillus fusiformis (SPS11) and Lysinibacillus sphaericus (NAS32) using 16s rRNA. These two strains should be further studied in in vivo challenged experiments in fish and shellfish to explore their probiotic effects.

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Herbicide Potential of Selected Essential Oils From Plants of Lamiaceae and Asteraceae Families

Acta Agrobotanica ◽

10.5586/aa.7411 ◽

2021 ◽

Vol 74 ◽

Author(s):

Milena Nikolova ◽

Boryanka Traykova ◽

Elina Yankova-Tsvetkova ◽

Tatyana Stefanova ◽

Anatoli Dzhurmanski ◽

...

Keyword(s):

Seed Germination ◽

Essential Oil ◽

Essential Oils ◽

Trifolium Pratense ◽

Herbicidal Activity ◽

Field Conditions ◽

In Vitro Assays ◽

Gas Chromatography Mass Spectrometry ◽

Monarda Fistulosa

Abstract Essential oils from Monarda fistulosa L., Satureja pilosa Vel., Origanum vulgare subsp. hirtum Ietswaart. (Greek oregano), Micromeria dalmatica Benth., Thymus longedentatus (Degen & Urum.) Ronniger, and Artemisa campestris L. were evaluated as inhibitors of seed germination in target plants Lolium perenne L. and Trifolium pratense L. using in vitro assays. The essential oils were applied on the seeds as aqueous solutions at concentrations ranging from 0.5–3.0 µL/mL. Complete inhibition was established at a concentration of 1.5 µL/mL with the most effective essential oils. Oregano oil was evaluated for its inhibitory activity on seed germination under field conditions; the essential oil was applied as an aqueous solution at concentrations of 3, 5, and 10 µL/mL on superabsorbent Terawet. The mass obtained was mixed with the seeds of the target plants and planted in a field. After 1 month, the results were evaluated based on the weight of the aerial parts of the plants from control and experimental areas. At the highest concentration studied, the weight of the plants was 77% lower in the experimental areas than in the controls. The chemical composition of the essential oils was analyzed using gas chromatography–mass spectrometry. The results showed that carvacrol-rich essential oils had a strong inhibitory effect on seed germination. The inclusion of the essential oil on a superabsorbent was a good way to preserve its herbicidal activity under field conditions as this prevented its rapid evaporation.

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Exploring Potential Soil Bacteria for Sustainable Wheat (Triticum aestivum L.) Production

Sustainability ◽

10.3390/su11123361 ◽

2019 ◽

Vol 11 (12) ◽

pp. 3361 ◽

Cited By ~ 11

Author(s):

Rizwan Ali Sheirdil ◽

Rifat Hayat ◽

Xiao-Xia Zhang ◽

Nadeem Akhtar Abbasi ◽

Safdar Ali ◽

...

Keyword(s):

Crop Production ◽

Sandy Loam ◽

Acc Deaminase ◽

Dry Weight ◽

Plant Growth Promoting Rhizobacteria ◽

Triticum Aestivum L ◽

Growth Chamber ◽

In Vitro Assays ◽

The Impact

The application of plant growth-promoting rhizobacteria (PGPR) could allow growers to reduce the use of synthetic fertilizers and increase the sustainability of crop production. Wheat is the main staple food crop of Pakistan, and few studies have reported on the impact of PGPR on wheat crops. To determine if PGPR can maintain wheat productivity with reduced fertilizer applications, we isolated bacteria from the rhizosphere of wheat grown in sandy loam. We selected 10 strains based on in vitro assays for traits associated with PGPR: ACC deaminase activity, siderophore productivity, P-solubilization, and productivity of indole acetic acid (IAA). Furthermore, the strains were tested in three experiments (using a growth-chamber, pots with an experimental area of 0.05 m2, and a field). Strains that possessed the four traits associated with PGPR increased the shoot length, root length, and fresh and dry weight of plants in the growth chamber study. Similarly, under the pot trial, maximum crop traits were observed under the consortium + half dose, while under field conditions maximum crop parameters were detected in the case of consortium 1 and consortium 2 along with half the recommended dose of fertilizer. This confirms that this consortium could provide growers with a sustainable approach to reduce synthetic fertilizer usage in wheat production.

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