scholarly journals Involvement of Phenazines and Anthranilate in the Antagonism of Pseudomonas aeruginosa PNA1 and Tn5 Derivatives Toward Fusarium spp. and Pythium spp.

1998 ◽  
Vol 11 (9) ◽  
pp. 847-854 ◽  
Author(s):  
Vanamala Anjaiah ◽  
Nico Koedam ◽  
Brian Nowak-Thompson ◽  
Joyce E. Loper ◽  
Monica Höfte ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Fusarium Wilt ◽  
Parental Strain ◽  
Mycelial Growth ◽  
Biosynthesis Pathway ◽  
Tryptophan Biosynthesis ◽  
Damping Off ◽  
Glycerol Phosphate ◽  
Pythium Splendens ◽  
Phenazine Production

Pseudomonas aeruginosa PNA1, isolated from the rhizosphere of chickpea in India, suppressed Fusarium wilt of chickpea, caused by Fusarium oxysporum f. sp. ciceris, and Pythium damping-off of bean, caused by Pythium splendens. When grown in culture, PNA1 produced the phenazine antibiotics phenazine-1-carboxylic acid and oxychloraphine, and inhibited mycelial growth of F. oxysporum f. sp. ciceris, P. splendens, and certain other phytopathogenic fungi. Two mutants (FM29 and FM13) deficient in phenazine production were obtained following transposon mutagenesis of PNA1. The transposon in the genome of FM29 was localized to phnA, which is thought to encode a subunit of anthranilate synthase II involved in the phenazine biosynthesis. The FM13 mutation was complemented by trpC, which encodes indole glycerol phosphate synthase in the tryptophan biosynthesis pathway; consequently, FM13 could not grow on a minimal medium in the absence of tryptophan. Neither FM29 nor FM13 suppressed Fusarium wilt of chickpea to the level achieved by the wild-type strain, indicating that phenazine production contributed to the biocontrol of this disease by P. aeruginosa PNA1. FM29 was also less effective than the phenazine-producing parental strain in biological control of Pythium damping-off of bean, but FM13 was as effective as the parental strain in suppressing this disease. Anthranilate, an intermediate in the tryptophan biosynthesis pathway, suppressed mycelial growth of Pythium spp. in culture and Pythium damping-off of bean and lettuce. Anthranilate, excreted by FM13 as a consequence of the trpC mutation, may have contributed to the suppression of Pythium damping-off by the mutant.

scholarly journals In-vitro compatibility assay of indigenous Trichoderma and Pseudomonas species and their antagonistic activities against black root rot disease (Fusarium solani) of faba bean (Vicia faba L.)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Alemayehu Dugassa ◽  
Tesfaye Alemu ◽  
Yitbarek Woldehawariat
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pseudomonas Fluorescens ◽  
Faba Bean ◽  
Fusarium Solani ◽  
Root Rot ◽  
Mycelial Growth ◽  
Biocontrol Agents ◽  
Black Root Rot ◽  
Root Rot Disease ◽  
Rot Disease

Abstract Background Faba bean (Vicia faba L.) cultivation is highly challenged by faba bean black root rot disease (Fusarium solani) in high lands of Ethiopia. To ensure sustainable production of faba beans, searching for eco-friendly disease management options is necessary to curb the progress of the disease timely. The indigenous biocontrol agents that suit local environments may effectively strive with in-situ microorganisms and suppress local pathogen strains. This study aimed to screen antagonistic indigenous compatible Trichoderma and Pseudomonas strains against Fusarium solani. In the pathogenicity test, soil-filled pots were arranged in complete random block design and sown with health faba bean seeds. The effect of some fungicides was evaluated against Fusarium by food poisoning methods to compare with the biocontrol agents. The antagonistic efficacy of biocontrol agents and their compatibility was investigated on Potato dextrose agar medium. Results Fusarium solani AAUF51 strain caused an intense root rotting in faba bean plant. The effect of Mancozeb 80% WP at 300 ppm was comparable with Trichoderma and Pseudomonas strains against Fusarium. The mycelial growth of test the pathogen was significantly (P ≤ 0.05) reduced to 86.67 and 85.19% by Trichoderma harzianum AAUW1 and Trichoderma viridae AAUC22 strains in dual culture, respectively. The volatile metabolites of Pseudomonas aeruginosa AAUS31 (77.78%) found the most efficient in reducing mycelial growth of Fusarium followed by Pseudomonas fluorescens AAUPF62 (71.11%) strains. The cell-free culture filtrates of Pseudomonas fluorescens AAUPF62 and Pseudomonas aeruginosa AAUS31 were more efficient than the Trichoderma strain in reducing the growth of Fusarium isolates. There was no zone of inhibition recorded between Trichoderma harzianum AAUW1, Trichoderma viridae AAUC22, Pseudomonas aeruginosa AAUS31, and Pseudomonas fluorescens AAUPF62 strains, hence they were mutually compatible. Conclusions The compatible Trichoderma and Pseudomonas strains showed antagonistic potentiality that could be explored for faba bean protection against black root rot disease and might have a future dual application as biocontrol agents.

scholarly journals Strain- and Substrate-Dependent Redox Mediator and Electricity Production by Pseudomonas aeruginosa

2016 ◽  
Vol 82 (16) ◽  
pp. 5026-5038 ◽  
Author(s):  
Erick M. Bosire ◽  
Lars M. Blank ◽  
Miriam A. Rosenbaum
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Electron Transfer ◽  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Pure Culture ◽  
Bioelectrochemical Systems ◽  
Content Type ◽  
Mediated Electron Transfer ◽  
Phenazine Production ◽  
Model Strain

ABSTRACTPseudomonas aeruginosais an important, thriving member of microbial communities of microbial bioelectrochemical systems (BES) through the production of versatile phenazine redox mediators. Pure culture experiments with a model strain revealed synergistic interactions ofP. aeruginosawith fermenting microorganisms whereby the synergism was mediated through the shared fermentation product 2,3-butanediol. Our work here shows that the behavior and efficiency ofP. aeruginosain mediated current production is strongly dependent on the strain ofP. aeruginosa. We compared levels of phenazine production by the previously investigated model strainP. aeruginosaPA14, the alternative model strainP. aeruginosaPAO1, and the BES isolatePseudomonassp. strain KRP1 with glucose and the fermentation products 2,3-butanediol and ethanol as carbon substrates. We found significant differences in substrate-dependent phenazine production and resulting anodic current generation for the three strains, with the BES isolate KRP1 being overall the best current producer and showing the highest electrochemical activity with glucose as a substrate (19 μA cm−2with ∼150 μg ml−1phenazine carboxylic acid as a redox mediator). Surprisingly,P. aeruginosaPAO1 showed very low phenazine production and electrochemical activity under all tested conditions.IMPORTANCEMicrobial fuel cells and other microbial bioelectrochemical systems hold great promise for environmental technologies such as wastewater treatment and bioremediation. While there is much emphasis on the development of materials and devices to realize such systems, the investigation and a deeper understanding of the underlying microbiology and ecology are lagging behind. Physiological investigations focus on microorganisms exhibiting direct electron transfer in pure culture systems. Meanwhile, mediated electron transfer with natural redox compounds produced by, for example,Pseudomonas aeruginosamight enable an entire microbial community to access a solid electrode as an alternative electron acceptor. To better understand the ecological relationships between mediator producers and mediator utilizers, we here present a comparison of the phenazine-dependent electroactivities of threePseudomonasstrains. This work forms the foundation for more complex coculture investigations of mediated electron transfer in microbial fuel cells.

scholarly journals Induction of Soil Suppressiveness Against Rhizoctonia solani by Incorporation of Dried Plant Residues into Soil

2006 ◽  
Vol 96 (12) ◽  
pp. 1372-1379 ◽  
Author(s):  
Masahiro Kasuya ◽  
Andriantsoa R. Olivier ◽  
Yoko Ota ◽  
Motoaki Tojo ◽  
Hitoshi Honjo ◽  
...  
Keyword(s):  
Rhizoctonia Solani ◽  
Mycelial Growth ◽  
Inhibitory Effect ◽  
Volatile Substance ◽  
Disease Suppression ◽  
Plant Residues ◽  
Infested Soil ◽  
Antagonistic Bacteria ◽  
Damping Off ◽  
Soil Suppressiveness

Suppressive effects of soil amendment with residues of 12 cultivars of Brassica rapa on damping-off of sugar beet were evaluated in soils infested with Rhizoctonia solani. Residues of clover and peanut were tested as noncruciferous controls. The incidence of damping-off was significantly and consistently suppressed in the soils amended with residues of clover, peanut, and B. rapa subsp. rapifera ‘Saori’, but only the volatile substance produced from water-imbibed residue of cv. Saori exhibited a distinct inhibitory effect on mycelial growth of R. solani. Nonetheless, disease suppression in such residue-amended soils was diminished or nullified when antibacterial antibiotics were applied to the soils, suggesting that proliferation of antagonistic bacteria resident to the soils were responsible for disease suppression. When the seed (pericarps) colonized by R. solani in the infested soil without residues were replanted into the soils amended with such residues, damping-off was suppressed in all cases. In contrast, when seed that had been colonized by microorganisms in the soils containing the residues were replanted into the infested soil, damping-off was not suppressed. The evidence indicates that the laimosphere, but not the spermosphere, is the site for the antagonistic microbial interaction, which is the chief principle of soil suppressiveness against Rhizoctonia damping-off.

scholarly journals Uji masa simpan pelet Trichoderma harzianum dan kemampuannya dalam menghambat perkembangan penyakit Layu Fusarium pada bibit tomat.

2018 ◽  
Vol 3 (2) ◽  
pp. 117-127
Author(s):  
Rizka Musfirah ◽  
Rina Sriwati ◽  
Tjut Chamzurni
Keyword(s):  
Vitamin A ◽  
Shelf Life ◽  
Fusarium Oxysporum ◽  
Solanum Lycopersicum ◽  
Plant Height ◽  
Incubation Period ◽  
Fusarium Wilt ◽  
Trichoderma Harzianum ◽  
Wilt Disease ◽  
Damping Off

Abstrak. Tomat (Solanum lycopersicum) merupakan salah satu komoditas pertanian yang ditanam secara luas di seluruh dunia, termasuk di Indonesia, karena memiliki rasa yang khas dan enak, juga memiliki nilai gizi seperti sumber vitamin A dan C yang sangat baik. Produksi tomat mengalami penurunan setiap tahun, salah satunya diakibatkan oleh organisme penganggu tanaman (OPT) yaitu patogen Fusarium oxysporum sehingga perlu dilakukan pengendalian hayati yaitu menggunakan Trichoderma harzianum dalam bentuk formulasi pelet yang praktis, efektif, dan efesien. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) non faktorial yang terdiri dari 6 perlakuan dengan 3 ulangan, setiap perlakuan terdiri dari 10 unit bibit tomat. Penelitian ini terdiri dari 6 perlakuan yaitu perlakuan A (masa simpan pelet T. harzianum  4 minggu), B (masa simpan pelet T. harzianum 3 minggu), C (masa simpan pelet T. harzianum 2 minggu), D (masa simpan pelet T. harzianum 1 minggu), E (masa simpan pelet T. harzianum 0 minggu), F (tanpa perlakuan pelet T. harzianum). Peubah yang diamati yaitu pre-emergence damping off, post-emergence damping off, masa inkubasi, persentase tanaman layu, tinggi tanaman, dan jumlah daun. Hasil penelitian menunjukkan bahwa pelet T. harzianum yang disimpan 4 minggu efektif dalam menghambat perkembangan penyakit layu fusarium seperti menunda masa inkubasi sampai 7 HSI, menekan pre-emergence damping off sampai 90%, post-emergence damping off 92,95%, serta mampu meningkatkan tinggi tanaman sampai 19,63 cm dan meningkatkan jumlah daun rata-rata 7 helai pada 35 HSI. (Storing Period of Trichoderma harzianum Pellets and its ability to Inhibit the development of Fusarium Wilt Disease on Tomato Seeds)Abstract. Tomato (Solanum lycopersicum) is one of the most widely grown commodities in the world, including Indonesia. It has a distinctively good taste and many nutritional value such as vitamin A and C. However, tomato production has decreased every year. One of the main cause is the attacks by pathogens, named Fusarium oxysporum. A Biological control is necessary and the use of Trichoderma harzianum in the form of pellets is recommended because of its effectiveness, efficiency and practical use. This research used a Completely Randomized Design (RAL) non-factorial consisted of 6 treatments with 3 replications, each treatment consisted of 10 units of tomato seedlings. The 6 treatments are named as treatment A (T. harzianum pellet saving 4 weeks), B (T. harzianum pellet saving period 3 weeks), C (shelf life of 2 weeks T. harzianum pellet), D (shelf life of pellet T harzianum 1 week), E (shelf life of pellet T. harzianum 0 weeks), and F (without T. harzianum pellet treatment). The variables observed in this study are pre-emergence damping off, post-emergence damping off, incubation period, the percentage of wilted plants, plant height, and the number of leaves. The results showed that pellets of T. harzianum stored 4 weeks effectively inhibiting the development of fusarium wilt disease such as delaying incubation period up to 7 HSI (Days After Incubation), suppressing the pre-emergence damping off up to 90% and post-emergence damping off to 92.95%, also able to increase the plant height up to 19.63 cm and increase the average leaf number of 7 strands at 35 HSI.

An alkaline phosphatase mutant of Pseudomonas aeruginosa. 1. Effects of regulatory, structural, and environmental shifts on enzyme function

1978 ◽  
Vol 24 (4) ◽  
pp. 427-432 ◽  
Author(s):  
M. L. Marceau-Day ◽  
D. F Day ◽  
J. M. Ingram
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Alkaline Phosphatase ◽  
Core Region ◽  
Significant Activity ◽  
Wild Type ◽  
Glycerol Phosphate ◽  
The Core ◽  
Nitrophenyl Phosphate ◽  
Mutant Cells

An alkaline phosphatase mutant of Pseudomonas aeruginosa exhibiting both regulatory and catalytic changes was isolated. Under repression conditions (i.e. high inorganic phosphate (Pi)) the mutant culture produced an alkaline phosphatase (APase) displaying significant activity against both β-glycerol phosphate (βGP) and p-nitrophenyl phosphate (pNPP), while the wild type displayed no activity directed towards these substrates under the same conditions. In vivo, the mutant enzyme's ratio of specific activities was 45:1 in favour of βGP versus pNPP, whereas this ratio was reversed to 1:9 βGP versus pNPP for the same enzyme isolated from mutant cells. In addition, the kinetic parameters and stability requirements for the mutant-derived enzyme was altered in comparison with those of the wild type. A study of lipopolysaccharide(LPS) preparations from both the mutant and wild type indicated the mutant to be deficient in the core region of its LPS. The authors propose that the modifications in the catalytic activity of the mutant enzyme, demonstrated in vivo, are due to a change in the enzyme's microenvironment.

scholarly journals Biosynthesis of the Unique Wall Teichoic Acid of Staphylococcus aureus Lineage ST395

mBio ◽  
2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Volker Winstel ◽  
Patricia Sanchez-Carballo ◽  
Otto Holst ◽  
Guoqing Xia ◽  
Andreas Peschel
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Biosynthesis Pathway ◽  
Glycerol Phosphate ◽  
Coagulase Negative Staphylococci ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Wall Teichoic Acids

ABSTRACT The major clonal lineages of the human pathogen Staphylococcus aureus produce cell wall-anchored anionic poly-ribitol-phosphate (RboP) wall teichoic acids (WTA) substituted with d-Alanine and N-acetyl-d-glucosamine. The phylogenetically isolated S. aureus ST395 lineage has recently been found to produce a unique poly-glycerol-phosphate (GroP) WTA glycosylated with N-acetyl-d-galactosamine (GalNAc). ST395 clones bear putative WTA biosynthesis genes on a novel genetic element probably acquired from coagulase-negative staphylococci (CoNS). We elucidated the ST395 WTA biosynthesis pathway and identified three novel WTA biosynthetic genes, including those encoding an α-O-GalNAc transferase TagN, a nucleotide sugar epimerase TagV probably required for generation of the activated sugar donor substrate for TagN, and an unusually short GroP WTA polymerase TagF. By using a panel of mutants derived from ST395, the GalNAc residues carried by GroP WTA were found to be required for infection by the ST395-specific bacteriophage Φ187 and to play a crucial role in horizontal gene transfer of S. aureus pathogenicity islands (SaPIs). Notably, ectopic expression of ST395 WTA biosynthesis genes rendered normal S. aureus susceptible to Φ187 and enabled Φ187-mediated SaPI transfer from ST395 to regular S. aureus. We provide evidence that exchange of WTA genes and their combination in variable, mosaic-like gene clusters have shaped the evolution of staphylococci and their capacities to undergo horizontal gene transfer events. IMPORTANCE The structural highly diverse wall teichoic acids (WTA) are cell wall-anchored glycopolymers produced by most Gram-positive bacteria. While most of the dominant Staphylococcus aureus lineages produce poly-ribitol-phosphate WTA, the recently described ST395 lineage produces a distinct poly-glycerol-phosphate WTA type resembling the WTA backbone of coagulase-negative staphylococci (CoNS). Here, we analyzed the ST395 WTA biosynthesis pathway and found new types of WTA biosynthesis genes along with an evolutionary link between ST395 and CoNS, from which the ST395 WTA genes probably originate. The elucidation of ST395 WTA biosynthesis will help to understand how Gram-positive bacteria produce highly variable WTA types and elucidate functional consequences of WTA variation.

scholarly journals Role of LecA and LecB Lectins in Pseudomonas aeruginosa-Induced Lung Injury and Effect of Carbohydrate Ligands

2009 ◽  
Vol 77 (5) ◽  
pp. 2065-2075 ◽  
Author(s):  
Chanez Chemani ◽  
Anne Imberty ◽  
Sophie de Bentzmann ◽  
Maud Pierre ◽  
Michaela Wimmerová ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Parental Strain ◽  
A549 Cells ◽  
Carbohydrate Ligands ◽  
Vitro Model

ABSTRACT Pseudomonas aeruginosa is a frequently encountered pathogen that is involved in acute and chronic lung infections. Lectin-mediated bacterium-cell recognition and adhesion are critical steps in initiating P. aeruginosa pathogenesis. This study was designed to evaluate the contributions of LecA and LecB to the pathogenesis of P. aeruginosa-mediated acute lung injury. Using an in vitro model with A549 cells and an experimental in vivo murine model of acute lung injury, we compared the parental strain to lecA and lecB mutants. The effects of both LecA- and Lec B-specific lectin-inhibiting carbohydrates (α-methyl-galactoside and α-methyl-fucoside, respectively) were evaluated. In vitro, the parental strain was associated with increased cytotoxicity and adhesion on A549 cells compared to the lecA and lecB mutants. In vivo, the P. aeruginosa-induced increase in alveolar barrier permeability was reduced with both mutants. The bacterial burden and dissemination were decreased for both mutants compared with the parental strain. Coadministration of specific lectin inhibitors markedly reduced lung injury and mortality. Our results demonstrate that there is a relationship between lectins and the pathogenicity of P. aeruginosa. Inhibition of the lectins by specific carbohydrates may provide new therapeutic perspectives.

Abiotic Compounds as Inducers of Resistance to Fusarium Wilt in Tomatoes

2018 ◽  
Vol 10 (9) ◽  
pp. 373
Author(s):  
Jose R. M. Campos Neto ◽  
Leonardo de J. M. G. de Oliveira ◽  
Nathalia B. Diniz ◽  
Ivaneide de O. Nascimento ◽  
Antonia Alice C. Rodrigues
Keyword(s):  
Polyphenol Oxidase ◽  
Fusarium Wilt ◽  
Mycelial Growth ◽  
Rating Scale ◽  
Systemic Resistance ◽  
Activity Levels ◽  
Neem Oil ◽  
In Vivo Experiments

To study the effects of resistance inducers used to control fusarium wilt in tomatoes due to the fungus Fusarium oxysporum Schlecht f. sp. lycopersici, we evaluated the effects of ASM (acibenzolar-S-methyl), Agro-Mos, chitosan, Biopirol and neem oil on F. oxysporum f. sp. lycopersici mycelial growth and sporulation and systemic resistance in tomatoes. In vitro experiments comprised evaluations of the products’ effects on the mycelial growth and sporulation of the PDA (potato dextrose agar) growth medium-cultured pathogen. In vivo experiments included product application to tomato plants of the Santa Cruz cultivar that were grown for 25 days on autoclaved soil, followed by determinations of disease severity and peroxidase, polyphenol oxidase and Beta-1,3-glucanase enzyme activity levels, which are related to the process of resistance induction. Pathogen inoculation occurred after 5 days at a concentration of 106 conidia/mL. We evaluated the disease according to a rating scale. Enzymatic activity was determined according to specific protocols. Neem oil controlled pathogen mycelial growth and sporulation, while ASM influenced sporulation. The products reduced the severity of wilt in the plants. We highlight neem oil, Agro-Mos and Biopirol due to their ability to induce significant peroxidase, polyphenol oxidase and Beta-1,3-glucanase expression, respectively.

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