Characterization of the biocontrol activity of Debaryomyces hansenii in the control of Penicillium digitatum on grapefruit

1989 ◽  
Vol 35 (8) ◽  
pp. 794-800 ◽  
Author(s):  
S. Droby ◽  
E. Chalutz ◽  
C. L. Wilson ◽  
M. Wisniewski
Keyword(s):  
Biological Control ◽  
Debaryomyces Hansenii ◽  
Hyphal Growth ◽  
Significant Inhibition ◽  
Penicillium Digitatum ◽  
Yeast Cells ◽  
Fruit Peel ◽  
Control Activity ◽  
Green Mold ◽  
Synthetic Growth Medium

Interactions between Debaryomyces hansenii and Penicillium digitatum were studied in culture and on fruit to better characterize the observed biological control of green mold on grapefruit by the yeast. The antagonist did not produce antibiotic substances in culture and was ineffective in protecting against the disease when killed by heat or chemicals. Incidence of green mold was dependent upon the concentration of both the pathogen spores and the antagonist yeast cells. Control of green mold was most effective at 109 cfu/mL of D. hansenii. The role of available nutrients in the biological control activity of D. hansenii was assessed. Significant inhibition of spore germination and hyphal growth of P. digitatum in culture was achieved by the addition of the yeast cells to a minimal synthetic growth medium. Inhibition of P. digitatum by the antagonist in culture and on the fruit peel could be overcome by the addition of exogenous nutrients. Our results indicate that competition for nutrients may play a role in the biocontrol of P. digitatum by D. hansenii on grapefruit.Key words: biological control, Penicillium digitatum, Debaryomyces hansenii, grapefruit.

scholarly journals Influence of CaCl2 on Penicillium digitatum, Grapefruit Peel Tissue, and Biocontrol Activity of Pichia guilliermondii

1997 ◽  
Vol 87 (3) ◽  
pp. 310-315 ◽  
Author(s):  
S. Droby ◽  
M. E. Wisniewski ◽  
L. Cohen ◽  
B. Weiss ◽  
D. Touitou ◽  
...  
Keyword(s):  
Spore Germination ◽  
Large Scale ◽  
Debaryomyces Hansenii ◽  
Penicillium Digitatum ◽  
Yeast Cells ◽  
Pichia Guilliermondii ◽  
Enzyme Preparations ◽  
Green Mold ◽  
Grapefruit Peel ◽  
Yeast Antagonist

Interactions between CaCl2, grapefruit peel tissue, Penicillium digitatum, and the yeast antagonist Pichia guilliermondii strain US-7 were investigated. Application of 68 or 136 mM CaCl2 to grapefruit surface wounds reduced the incidence of green mold caused by Penicillium digitatum by 43 to 52%. In laboratory tests, a cell suspension (107 cells/ml) of Pichia guilliermondii containing either 68 or 136 mM CaCl2 reduced the incidence of green mold from 27 to 3%. In large scale tests, dip application of 136 mM CaCl2 with US-7 (107 cells/ml) significantly decreased the number of wounds infected by Penicillium digitatum. CaCl2, with or without yeast cells, stimulated ethylene production in grapefruit tissue. Increasing concentrations of CaCl2 resulted in decreased spore germination and germ tube elongation of Penicillium digitatum. Pectinolytic activity of crude enzyme preparations of Penicillium digitatum was also inhibited by the presence of increasing concentrations of CaCl2. US-7 exhibited a strong ability to maintain cytosolic Ca2+ homeostasis at levels that did not exceed 1.4 μM when exposed to 150 mM CaCl2. On the other hand, strain 114 of Debaryomyces hansenii, which failed to give any protection against infection by Penicillium digitatum, showed reduced capacity to maintain Ca2+ homeostasis. The effect of calcium in reducing infection of grapefruit wounds by Penicillium digitatum could be due to direct effects on host tissue (making cell walls more resistant to enzymatic degradation) or the pathogen (interfering with spore germination, growth, and inhibition of fungal pectinolytic enzymes). Alternatively, the ability of US-7 to maintain calcium homeostasis may allow it to grow or assist in its competitive ability in a microenvironment that, because of high levels of calcium ions, is inhibitory to growth of the green mold pathogen.

scholarly journals Natural Biostimulants Elicit Plant Immune System in an Integrated Management Strategy of the Postharvest Green Mold of Orange Fruits Incited by Penicillium digitatum

2021 ◽  
Vol 12 ◽  
Author(s):  
Federico La Spada ◽  
Francesco Aloi ◽  
Maurizio Coniglione ◽  
Antonella Pane ◽  
Santa Olga Cacciola
Keyword(s):  
Integrated Management ◽  
Penicillium Digitatum ◽  
The European Union ◽  
Citrus Fruits ◽  
Fruit Peel ◽  
Residual Concentration ◽  
Citrus Peel ◽  
Reduced Dose ◽  
Green Mold ◽  
Potassium Phosphite

This study was aimed at testing the integrated use of a natural biostimulant based on seaweed (Ascophyllum nodosum) and plant (alfalfa and sugarcane) extracts and reduced dosages of the conventional synthetic fungicide Imazalil (IMZ) to manage postharvest rots of orange fruits. The following aspects were investigated: (i) the effectiveness of postharvest treatment with natural biostimulant alone or in mixture with IMZ at a reduced dose against green mold caused by Penicillium digitatum; (ii) the differential expression of defense genes in orange fruits treated with the natural biostimulant both alone and in combination with a reduced dose of IMZ; (iii) the persistence of the inhibitory activity of both biostimulant and the mixture biostimulant/IMZ against green mold; and (iv) the residue level of fungicide in citrus peel when applied alone or in combination with the biostimulant. Treatments with the chemical plant resistance-inducer potassium phosphite, alone or with a reduced dose of IMZ, were included for comparison. The mixture of natural biostimulant and IMZ at a low dose consistently reduced the incidence and severity of fruit green mold and induced a significant increase of the expression level of β-1,3-glucanase-, peroxidase (PEROX)-, and phenylalanine ammonia-lyase (PAL)-encoding genes in fruit peel, suggesting that the natural biostimulant elicits a long-lasting resistance of citrus fruits to infections by P. digitatum. Interestingly, the residual concentration of IMZ in fruits treated with the biostimulant/fungicide mixture was significantly lower than that of IMZ in fruits treated only with the fungicide at the same dose and by far below the threshold values set by the European Union. This study laid the foundations for (i) conceiving a practical and more eco-friendly alternative to the conventional postharvest management of green mold of citrus fruits, based almost exclusively on the use of synthetic fungicide IMZ, alone or mixed with potassium phosphite and (ii) providing a better insight into the mechanisms of disease resistance induction by biostimulants.

Meeting the Kyoto target: implications for the Australian livestock industries

1999 ◽  
Vol 50 (8) ◽  
pp. I
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Hyphal Growth ◽  
Root Disease ◽  
Biological Control Agents ◽  
Control Activity ◽  
Matter Production

The interaction between 29 isolates of Rhizobium and the in vitro growth of 3 strains of Phytophthora clandestina was investigated to determine the potential of these bacteria as biological control agents against root rot of subterranean clover (Trifolium subterraneum L.). The biological control activity of Rhizobium on the severity of root disease in seedlings was also investigated under glasshouse conditions. Thirteen of the 29 Rhizobium isolates caused significant reductions in the hyphal growth of the 3 P. clandestina isolates examined. Inoculation of seedlings with Rhizobium trifolii reduced the severity of root disease by 14–58% with corresponding increases in dry matter production of 20–73%. These results indicate that Rhizobium species have potential as biological control agents against the root rot of T. subterraneum seedlings caused by P. clandestina.

Biological control of Fusarium wilt of cucumber with nonpathogenic isolates of Fusarium oxysporum

1987 ◽  
Vol 33 (5) ◽  
pp. 349-353 ◽  
Author(s):  
T. C. Paulitz ◽  
C. S. Park ◽  
R. Baker
Keyword(s):  
Biological Control ◽  
Fusarium Oxysporum ◽  
Infection Rate ◽  
Fusarium Wilt ◽  
Disease Incidence ◽  
Infection Rates ◽  
Control Activity ◽  
Significant Difference ◽  
Cucumber Roots ◽  
Linear Regressions

Nonpathogenic isolates of Fusarium oxysporum were obtained from surface-disinfested, symptomless cucumber roots grown in two raw (nonautoclaved) soils. These isolates were screened for pathogenicity and biological control activity against Fusarium wilt of cucumber in raw soil infested with Fusarium oxysporum f. sp. cucumerinum (F.o.c.). The influence of three isolates effective in inducing suppressiveness and three ineffective isolates on disease incidence over time was tested. The effective isolates reduced the infection rate (R), based on linear regressions of data transformed to loge (1/1 – y). Effective isolate C5 was added to raw soil infested with various inoculum densities of F.o.c. In treatments without C5, the increase in inoculum densities of F.o.c. decreased the incubation period of wilt disease, but there was no significant difference in infection rate among the inoculum density treatments. Isolate C5 reduced the infection rate at all inoculum densities of F.o.c. Various inoculum densities of C5 were added to raw soils infested with 1000 cfu/g of F.o.c. In the first trial, infection rates were reduced only in the treatment with 10 000 cfu/g of C5; in the second trial, infection rates were reduced in treatments with 10 000 and 30 000 cfu/g of C5.

scholarly journals Cuticular hydrocarbons discriminate cryptic Macrolophus species (Hemiptera: Miridae)

2012 ◽  
Vol 102 (6) ◽  
pp. 624-631 ◽  
Author(s):  
C. Gemeno ◽  
N. Laserna ◽  
M. Riba ◽  
J. Valls ◽  
C. Castañé ◽  
...  
Keyword(s):  
Biological Control ◽  
Cuticular Hydrocarbons ◽  
Cross Validation ◽  
Molecular Genetic ◽  
Cuticular Hydrocarbon ◽  
Hydrocarbon Composition ◽  
Dark Spot ◽  
Prediction Errors ◽  
Control Activity ◽  
Genetic Studies

AbstractMacrolophus pygmaeus is commercially employed in the biological control of greenhouse and field vegetable pests. It is morphologically undistinguishable from the cryptic species M. melanotoma, and this interferes with the evaluation of the biological control activity of M. pygmaeus. We analysed the potential of cuticular hydrocarbon composition as a method to discriminate the two Macrolophus species. A third species, M. costalis, which is different from the other two species by having a dark spot at the tip of the scutellum, served as a control. Sex, diet and species, all had significant effects in the cuticular hydrocarbon profiles, but the variability associated to sex or diet was smaller than among species. Discriminant quadratic analysis of cuticular hydrocarbons confirmed the results of previous molecular genetic studies and showed, using cross-validation methods, that M. pygmaeus can be discriminated from M. costalis and M. melanotoma with prediction errors of 6.75% and 0%, respectively. Therefore, cuticular hydrocarbons can be used to separate M. pygmaeus from M. melanotoma reliably.

scholarly journals Mechanistically Compatible Mixtures of Bacterial Antagonists Improve Biological Control of Fire Blight of Pear

2011 ◽  
Vol 101 (1) ◽  
pp. 113-123 ◽  
Author(s):  
V. O. Stockwell ◽  
K. B. Johnson ◽  
D. Sugar ◽  
J. E. Loper
Keyword(s):  
Biological Control ◽  
Plant Disease ◽  
Fire Blight ◽  
Biological Control Agent ◽  
Field Trials ◽  
Control Agent ◽  
Extracellular Protease ◽  
Peptide Antibiotics ◽  
Biological Control Agents ◽  
Control Activity

Mixtures of biological control agents can be superior to individual agents in suppressing plant disease, providing enhanced efficacy and reliability from field to field relative to single biocontrol strains. Nonetheless, the efficacy of combinations of Pseudomonas fluorescens A506, a commercial biological control agent for fire blight of pear, and Pantoea vagans strain C9-1 or Pantoea agglomerans strain Eh252 rarely exceeds that of individual strains. A506 suppresses growth of the pathogen on floral colonization and infection sites through preemptive exclusion. C9-1 and Eh252 produce peptide antibiotics that contribute to disease control. In culture, A506 produces an extracellular protease that degrades the peptide antibiotics of C9-1 and Eh252. We hypothesized that strain A506 diminishes the biological control activity of C9-1 and Eh252, thereby reducing the efficacy of biocontrol mixtures. This hypothesis was tested in five replicated field trials comparing biological control of fire blight using strain A506 and A506 aprX::Tn5, an extracellular protease-deficient mutant, as individuals and combined with C9-1 or Eh252. On average, mixtures containing A506 aprX::Tn5 were superior to those containing the wild-type strain, confirming that the extracellular protease of A506 diminished the biological control activity of C9-1 and Eh252 in situ. Mixtures of A506 aprX::Tn5 and C9-1 or Eh252 were superior to oxytetracycline or single biocontrol strains in suppressing fire blight of pear. These experiments demonstrate that certain biological control agents are mechanistically incompatible, in that one strain interferes with the mechanism by which a second strain suppresses plant disease. Mixtures composed of mechanistically compatible strains of biological control agents can suppress disease more effectively than individual biological control agents.

The potential use of Debaryomyces hansenii for the biological control of pathogenic fungi in food

2018 ◽  
Vol 121 ◽  
pp. 216-222 ◽  
Author(s):  
Noé Medina-Córdova ◽  
Sergio Rosales-Mendoza ◽  
Luis Guillermo Hernández-Montiel ◽  
Carlos Angulo
Keyword(s):  
Biological Control ◽  
Debaryomyces Hansenii ◽  
Pathogenic Fungi ◽  
Potential Use

scholarly journals Immobilized Bacillus subtilis by ionic gelation as biocontrol alternative of Fusarium oxysporum f.sp. lycopersici

2018 ◽  
Author(s):  
Castañeda Alvarez Estefania ◽  
Sánchez Leal Ligia
Keyword(s):  
Biological Control ◽  
Bacillus Subtilis ◽  
Fusarium Oxysporum ◽  
Sodium Alginate ◽  
Ionic Gelation ◽  
Cellular Viability ◽  
Market Demand ◽  
Control Activity ◽  
Pests And Diseases

For farmers the use of agrochemicals is the preferred method to control pests and diseases. Considering the market demand for biological control products, the encapsulation could be a competent alternative to current commercial formulations for cellular viability and controlled release. The purpose of this study was to use ionic gelation with sodium alginate, starch and maltodextrin to immobilize Bacillus subtilis and to evaluate the biocontrol effect against Fusarium oxysporum f. sp. lycopersici in vitro. The matrix with a concentration of 2% sodium alginate, 1% starch, and 1% maltodextrin is a suitable method for cellular viability and biological control activity against Fusarium oxysporum f. sp. lycopersici, with a reduction of mycelial growth of 49.6% and a survival rate for Bacillus subtilis of 98.05% (p less than 0.0001).The use of immobilized bacteria as biological control agents are sustainable and effective bio-inputs that could be used at industrial scale and benefit the tomato crops against attack by Fusarium oxysporum f. sp. lycopersici.

scholarly journals Biological Control Activity of Two Isolates of Pseudomonas fluorescens against Rice Sheath Blight

2006 ◽  
Vol 22 (3) ◽  
pp. 289-294 ◽  
Author(s):  
Gyung-Ja Choi ◽  
Jin-Cheol Kim ◽  
Eun-Jin Park ◽  
Yong-Ho Choi ◽  
Kyoung-Soo Jang ◽  
...  
Keyword(s):  
Biological Control ◽  
Pseudomonas Fluorescens ◽  
Sheath Blight ◽  
Rice Sheath Blight ◽  
Control Activity

scholarly journals Methyl Salicylate Fails to Enhance Arthropod Predator Abundance or Predator to Pest Ratios in Cotton

2021 ◽  
Author(s):  
Steven E Naranjo ◽  
James R Hagler ◽  
John A Byers
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Natural Enemy ◽  
Methyl Salicylate ◽  
Production Systems ◽  
Control Function ◽  
Conservation Biological Control ◽  
Cotton Production ◽  
Control Activity ◽  
Synthetic Chemicals

Abstract Conservation biological control is a fundamental tactic in integrated pest management (IPM). Greater biological control services can be achieved by enhancing agroecosystems to be more favorable to the presence, survival, and growth of natural enemy populations. One approach that has been tested in numerous agricultural systems is the deployment of synthetic chemicals that mimic those produced by the plant when under attack by pests. These signals may attract arthropod natural enemies to crop habitats and thus potentially improve biological control activity locally. A 2-yr field study was conducted in the cotton agroecosystem to evaluate the potential of synthetic methyl salicylate (MeSA) to attract native arthropod natural enemies and to enhance biological control services on two key pests. Slow-release packets of MeSA were deployed in replicated cotton plots season long. The abundance of multiple taxa of natural enemies and two major pests were monitored weekly by several sampling methods. The deployment of MeSA failed to increase natural enemy abundance and pest densities did not decline. Predator to prey ratios, used as a proxy to estimate biological control function, also largely failed to increase with MeSA deployment. One exception was a season-long increase in the ratio of Orius tristicolor (White) (Hemiptera: Anthocoridae) to Bemisia argentifolii Bellows and Perring (= Bemisia tabaci MEAM1) (Hemiptera: Aleyrodidae) adults within the context of biological control informed action thresholds. Overall results suggest that MeSA would not likely enhance conservation biological control by the natural enemy community typical of U.S. western cotton production systems.

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