scholarly journals Identification of Pseudomonas fluorescens using different biochemical tests

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Bikram Nepali ◽  
Sabin Bhattarai ◽  
Jiban Shrestha
Keyword(s):  
Pseudomonas Fluorescens ◽  
Fungal Pathogens ◽  
Rice Seed ◽  
Fungal Metabolites ◽  
Maize Seed ◽  
Biochemical Tests ◽  
Pathology Laboratory ◽  
Fluorescent Pigment ◽  
Oxidase Test ◽  
Anti Fungal

Pseudomonas fluorescens not only enhances the plant growth but also controls the fungal pathogens by production of anti fungal metabolites. The objective of this experiment was to identify P. fluorescens using different biochemical tests. This research was carried out in Plant Pathology Laboratory at Agriculture and Forestry University (AFU), Rampur, Chitwan, Nepal. The result of this experiment indicated that P.  fluorescens gave positive result for Catalase test, Gelatin liquefaction, Fluorescent pigment and Oxidase test but negative result for starch hydrolysis test. The colony of P. fluorescens was maximum in maize seed than that of rice seed after two hours of inoculation, whereas higher number of colony was found in rice seed than that of maize seed after twenty four hours of seed inoculation. This findings is useful for identifying colony of P. fluorescens  per seed which is necessary for better seedling growth and effective biological control of pathogens.

scholarly journals Genome Mining and Evaluation of the Biocontrol Potential of Pseudomonas fluorescens BRZ63, a New Endophyte of Oilseed Rape (Brassica napus L.) against Fungal Pathogens

2020 ◽  
Vol 21 (22) ◽  
pp. 8740
Author(s):  
Daria Chlebek ◽  
Artur Pinski ◽  
Joanna Żur ◽  
Justyna Michalska ◽  
Katarzyna Hupert-Kocurek
Keyword(s):  
Brassica Napus ◽  
Plant Growth ◽  
Pseudomonas Fluorescens ◽  
Oilseed Rape ◽  
Plant Growth Promotion ◽  
Fungal Pathogens ◽  
Growth Promotion ◽  
Genome Mining ◽  
Plant Colonization ◽  
Brassica Napus L

Endophytic bacteria hold tremendous potential for use as biocontrol agents. Our study aimed to investigate the biocontrol activity of Pseudomonas fluorescens BRZ63, a new endophyte of oilseed rape (Brassica napus L.) against Rhizoctonia solani W70, Colletotrichum dematium K, Sclerotinia sclerotiorum K2291, and Fusarium avenaceum. In addition, features crucial for biocontrol, plant growth promotion, and colonization were assessed and linked with the genome sequences. The in vitro tests showed that BRZ63 significantly inhibited the mycelium growth of all tested pathogens and stimulated germination and growth of oilseed rape seedlings treated with fungal pathogens. The BRZ63 strain can benefit plants by producing biosurfactants, siderophores, indole-3-acetic acid (IAA), 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and ammonia as well as phosphate solubilization. The abilities of exopolysaccharide production, autoaggregation, and biofilm formation additionally underline its potential to plant colonization and hence biocontrol. The effective colonization properties of the BRZ63 strain were confirmed by microscopy observations of EGFP-expressing cells colonizing the root surface and epidermal cells of Arabidopsis thaliana Col-0. Genome mining identified many genes related to the biocontrol process, such as transporters, siderophores, and other secondary metabolites. All analyses revealed that the BRZ63 strain is an excellent endophytic candidate for biocontrol of various plant pathogens and plant growth promotion.

scholarly journals Antibiotic sensitivity and in vitro antimicrobial activity of plant extracts to pseudomonas fluorescens isolates collected from diseased fish

1970 ◽  
Vol 1 (4) ◽  
pp. 82-88 ◽  
Author(s):  
MJ Foysal ◽  
MM Rahman ◽  
M Alam
Keyword(s):  
Antibacterial Activity ◽  
Pseudomonas Fluorescens ◽  
Plant Extracts ◽  
Antibiotic Sensitivity ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Leaf Extracts ◽  
Sensitivity Pattern ◽  
Medicinal Plant Extracts

Studies were conducted to identify Pseudomonas fluorescens isolates from a collection of bacteria isolated from bacterial haemorrhagic septicaemia infected carp and catfish, evaluate their antibiotic sensitivity pattern and screen the antibacterial activity of some medicinal plant extracts against the isolates.. A total of 10 isolates were identified as P. fluorescens by morphological, physiological and biochemical tests. In vitro antibiotic sensitivity test of the P. fluorescens isolates were conducted by disc diffusion method for seven antibiotics where, all of the isolates were found to be sensitive only against streptomycin and gentamycin but, most of the isolates (80%) were found resistant to chloramphenicol (C). Moreover, eighty percent of the isolates showed resistance to multiple antibiotics. A total of 118 plant extracts were screened for their antibacterial activity against the P. fluorescens isolates where the isolates exhibited sensitivity to 30 samples. Leaf extracts of Tamarindus indicus, Terminalia chebula, Citrus aurantifolia, Eugenia caryophyllata and Spondias pinnata were found to inhibit the growth of all of the P. fluorescens isolates. DOI: http://dx.doi.org/10.3329/ijns.v1i4.9733 IJNS 2011 1(4): 82-88

scholarly journals Production of yellow-green fluorescent pigment by Pseudomonas fluorescens

2006 ◽  
Vol 49 (3) ◽  
pp. 411-419 ◽  
Author(s):  
Gildo Almeida da Silva ◽  
Erik Amazonas de Almeida
Keyword(s):  
Pseudomonas Fluorescens ◽  
Pigment Production ◽  
Siderophore Production ◽  
Mineral Salts ◽  
Fluorescent Pigment ◽  
Green Fluorescent

A medium was prepared from brewery waste yeast with and without mineral salts to study growth and yellow-green fluorescent pigment production (YGFP) by Pseudomonas fluorescens. The King's medium used for detection of siderophore production were expressively weaker inductors of YGFP formation when compared to FYE medium. Although FYE and CYE could be used for growth of P. fluorescens, only FYE was an attractive medium for detection of YGFP strain producers.

scholarly journals Structural basis of Blastomyces Endoglucanase-2 adjuvancy in anti-fungal and -viral immunity

2021 ◽  
Vol 17 (3) ◽  
pp. e1009324
Author(s):  
Lucas dos Santos Dias ◽  
Hannah E. Dobson ◽  
Brock Kingstad Bakke ◽  
Gregory C. Kujoth ◽  
Junfeng Huang ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Influenza A ◽  
Fungal Pathogens ◽  
Animal Studies ◽  
Structural Basis ◽  
Viral Immunity ◽  
Mucosal Vaccination ◽  
Clinical Observations ◽  
Protective Antibodies ◽  
Anti Fungal

The development of safe subunit vaccines requires adjuvants that augment immunogenicity of non-replicating protein-based antigens. Current vaccines against infectious diseases preferentially induce protective antibodies driven by adjuvants such as alum. However, the contribution of antibody to host defense is limited for certain classes of infectious diseases such as fungi, whereas animal studies and clinical observations implicate cellular immunity as an essential component of the resolution of fungal pathogens. Here, we decipher the structural bases of a newly identified glycoprotein ligand of Dectin-2 with potent adjuvancy, Blastomyces endoglucanase-2 (Bl-Eng2). We also pinpoint the developmental steps of antigen-specific CD4+ and CD8+ T responses augmented by Bl-Eng2 including expansion, differentiation and tissue residency. Dectin-2 ligation led to successful systemic and mucosal vaccination against invasive fungal infection and Influenza A infection, respectively. O-linked glycans on Bl-Eng2 applied at the skin and respiratory mucosa greatly augment vaccine subunit- induced protective immunity against lethal influenza and fungal pulmonary challenge.

scholarly journals Anti-fungal activities of constituents from Uvaria scheffleri and Artabotrys brachypetalus

2006 ◽  
Vol 51 (1) ◽  
pp. 79-86 ◽  
Author(s):  
A.C. Odebode ◽  
S.A. Jonker ◽  
C.C. Joseph ◽  
S.W. Wachira
Keyword(s):  
Fusarium Solani ◽  
Radial Growth ◽  
Fungal Pathogens ◽  
Dry Weight ◽  
Stem Bark ◽  
Inhibitory Effect ◽  
In Vitro Bioassay ◽  
Botryodiplodia Theobromae ◽  
Anti Fungal

The anti-fungal activity of schefflone, a mixture of dimmer, 3,5 dimethoxy carvacrol and annonaceous acetogenin, extracted from stem-bark and root of Uvaria scheffleri and Artabotrys bruchypetalus against Fusarium solani, Botryodiplodia theobromae, Asperillus niger and Aspergillus flavus was determined. An in-vitro bioassay showed that the minimum inhibitory effect of the compounds to the fungal pathogens occurred at 200 ppm in both radial growth and mycelia dry weight measurements. Acetogenin from A brachypetalus had a very strong anti-fungal effect on all the test fungi. The effects of the compounds were more pronounced on F solani than on the other. The bioassay methods also play a significant role in the sensitivity of the samples on the pathogens. .

scholarly journals Detection of the presence Aeromonas sp on nile tilapia cultured in floating net cage in lake Tondano

2013 ◽  
Vol 1 (3) ◽  
Author(s):  
Wandalia Tantu ◽  
Reiny A Tumbol ◽  
Sammy N.J Longdong
Keyword(s):  
Nile Tilapia ◽  
Production Test ◽  
Biochemical Tests ◽  
North Sulawesi ◽  
Gram Staining ◽  
Fish Samples ◽  
Oxidase Test ◽  
Net Cage ◽  
H2s Production ◽  
Average Body

The purpose of this study was to detect the presence of bacteria Aeromonas sp in tilapia (Oreochromis niloticus). Nine fish with an average body weight of 150-200 g were used in this study as samples. Sampling was conducted at three different locations which were representative of fish culture sites located on Lake Tondano. The number of sample gathered from each location was and 3 fish which were taken randomly. Fish samples were taken by using a scoop, then the samples were taken alive by placing in an oxygen-filled plastic separately and taken direcly to lab Fish Disease Control and Environmental Center, Tateli, Department of Marine and Fisheries of North Sulawesi province, for examination the presence of bacteria. Isolation of bacteria were conducted by taking samples from gill and kidney. This study was carried out from April - July 2013. Identification of the presence of bacteria was done through a series of observations of colony morphology and gram staining of bacteria, followed by a series of biochemical tests: oxidase test , catalase test , test TSIA , H2S production test , indole test , motility test , citrate test, and test O/F. It could be concluded that 22.22 % of farmed nile tilapia in Lake Tondano were infected with the Aeromonas sp with the following percentage from each site: Paleloan village 7.40% , 7.40% Toulimembet village, and 7.40% Eris village. Keywords: Aeromonas sp, isolation, nile tilapia, floating net cage, Lake Tondano

Biosynthesis and Regulation of Anti-Fungal Metabolites by Pseudomonads

Pseudomonas ◽  
2004 ◽  
pp. 637-670 ◽  
Author(s):  
John P. Morrissey ◽  
Meabh Cullinane ◽  
Abdelhamid Abbas ◽  
Genevieve L. Mark ◽  
Fergal O’ Gara
Keyword(s):  
Fungal Metabolites ◽  
Anti Fungal

Pseudomonads contribute to regulation ofPratylenchus penetrans(Nematoda) populations on apple

2018 ◽  
Vol 64 (11) ◽  
pp. 775-785 ◽  
Author(s):  
Tristan T. Watson ◽  
Tom A. Forge ◽  
Louise M. Nelson
Keyword(s):  
Pseudomonas Fluorescens ◽  
Protease Activity ◽  
Fungal Pathogens ◽  
Plant Biomass ◽  
Growth Promotion ◽  
In Vitro Growth ◽  
Pratylenchus Penetrans ◽  
Pseudomonas Spp ◽  
Orchard Soil

Inoculation with antagonistic soil microorganisms has shown potential to suppress replant disease of apple in orchard soils. Pseudomonas spp. may have the potential to reduce Pratylenchus penetrans populations on apple. Pseudomonas spp. were isolated from the rhizosphere of sweet cherry and screened for antagonistic characteristics. Two highly antagonistic Pseudomonas isolates, P10-32 and P10-42, were evaluated for growth promotion of apple seedlings, suppression of P. penetrans populations, and root colonization in soil from three orchards. During the isolate screening, Pseudomonas fluorescens P10-32 reduced in vitro growth of fungal pathogens, had protease activity, had capacity to produce pyrrolnitrin, suppressed P. penetrans populations, and increased plant biomass. Pseudomonas fluorescens P10-42 reduced in vitro growth of fungal pathogens, had protease activity, suppressed P. penetrans populations, and increased plant biomass. In potted orchard soil, inoculating apple with P. fluorescens P10-32 suppressed P. penetrans populations in one of the three soils examined. Inoculation with P. fluorescens P10-42 improved plant growth in two of the soils and suppressed P. penetrans abundance in one soil. In one of the soils, P. fluorescens P10-42 was detected on the roots 56 days postinoculation. Overall, we conclude that Pseudomonas spp. play a role in suppressing P. penetrans on apple in orchard soil.

scholarly journals Role of ptsP, orfT, and sss Recombinase Genes in Root Colonization by Pseudomonas fluorescens Q8r1-96

2006 ◽  
Vol 72 (11) ◽  
pp. 7111-7122 ◽  
Author(s):  
Olga V. Mavrodi ◽  
Dmitri V. Mavrodi ◽  
David M. Weller ◽  
Linda S. Thomashow
Keyword(s):  
Pseudomonas Fluorescens ◽  
Fungal Pathogens ◽  
Root Colonization ◽  
Genomic Library ◽  
Wheat Root ◽  
Gene Replacement ◽  
Nitrogen Utilization ◽  
Gaeumannomyces Graminis ◽  
Natural Soil ◽  
Recombinase Gene

ABSTRACT Pseudomonas fluorescens Q8r1-96 produces 2,4-diacetylphloroglucinol (2,4-DAPG), a polyketide antibiotic that suppresses a wide variety of soilborne fungal pathogens, including Gaeumannomyces graminis var. tritici, which causes take-all disease of wheat. Strain Q8r1-96 is representative of the D-genotype of 2,4-DAPG producers, which are exceptional because of their ability to aggressively colonize and maintain large populations on the roots of host plants, including wheat, pea, and sugar beet. In this study, three genes, an sss recombinase gene, ptsP, and orfT, which are important in the interaction of Pseudomonas spp. with various hosts, were investigated to determine their contributions to the unusual colonization properties of strain Q8r1-96. The sss recombinase and ptsP genes influence global processes, including phenotypic plasticity and organic nitrogen utilization, respectively. The orfT gene contributes to the pathogenicity of Pseudomonas aeruginosa in plants and animals and is conserved among saprophytic rhizosphere pseudomonads, but its function is unknown. Clones containing these genes were identified in a Q8r1-96 genomic library, sequenced, and used to construct gene replacement mutants of Q8r1-96. Mutants were characterized to determine their 2,4-DAPG production, motility, fluorescence, colony morphology, exoprotease and hydrogen cyanide (HCN) production, carbon and nitrogen utilization, and ability to colonize the rhizosphere of wheat grown in natural soil. The ptsP mutant was impaired in wheat root colonization, whereas mutants with mutations in the sss recombinase gene and orfT were not. However, all three mutants were less competitive than wild-type P. fluorescens Q8r1-96 in the wheat rhizosphere when they were introduced into the soil by paired inoculation with the parental strain.

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