Biological Control of Peach Fungal Pathogens by Commercial Products and Indigenous Yeasts

The potential use of the commercial biocontrol products Serenade (Bacillus subtilis QST-713) and Trichodex (Trichoderma harzianum Rifai strain T39) to inhibit the postharvest pathogenic molds Penicillium crustosum and Mucor circinelloides was investigated. Both products exhibited antagonistic activity in vitro against the pathogens, reducing their growth at different levels. In addition, epiphytic yeasts isolated from peaches were identified as Candida maltosa, Pichia fermentans, and Pichia kluyveri by PCR–restriction fragment length polymorphism of internal transcribed spacer regions and screened for antagonistic activity against the same molds. The efficacy of biocontrol in vitro was dependent on the concentration of the yeast cells. Optimal yeast concentrations were above 107 CFU ml−1. However, C. maltosa and P. fermentans were more effective than P. kluyveri in inhibiting molds. The exclusion of antifungal metabolite production and direct competition for nutrients or space with the pathogens was proposed as the mechanism of biocontrol. Application of biocontrol agents directly on artificially wounded peach fruits significantly reduced the incidence of mold rot during storage at 20°C.

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Expression in yeast of a Plasmodium vivax antigen of potential use in a human malaria vaccine.

Journal of Experimental Medicine ◽

10.1084/jem.165.4.1160 ◽

1987 ◽

Vol 165 (4) ◽

pp. 1160-1171 ◽

Cited By ~ 44

Author(s):

P J Barr ◽

H L Gibson ◽

V Enea ◽

D E Arnot ◽

M R Hollingdale ◽

...

Keyword(s):

Plasmodium Vivax ◽

Malaria Vaccine ◽

Yeast Cells ◽

Expression Vectors ◽

Conserved Sequence ◽

Repeat Domain ◽

Malaria Antigen ◽

High Dilutions ◽

Potential Use

DNA coding for 234 amino acids of the circumsporozoite (CS) protein of Plasmodium vivax was incorporated into yeast expression vectors. The DNA encoded all the repeat domain and codons for a highly conserved sequence, KLKQP, found in CS proteins from all malaria parasites. Yeast cells transformed with these autonomously replicating plasmids expressed, upon induction, high levels of the CS polypeptide. The malaria antigen was purified in good yields from yeast extracts and was injected into mice using alum as adjuvant. The antibodies recognized the authentic CS protein, and at high dilutions, they inhibited the invasion of hepatocytes by sporozoites in vitro.

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Identification and antagonistic activity in vitro of Bacillus spp. and Trichoderma spp. isolates against common phytopathogenic fungi

Revista Mexicana de Fitopatología Mexican Journal of Phytopathology ◽

10.18781/r.mex.fit.1507-1 ◽

2015 ◽

Cited By ~ 2

Author(s):

Claudio Rios-Velsaco ◽

Janeth Caro-Cisneros ◽

David Berlanga-Reyes ◽

Maria Fernanda Ruíz-Cisneros ◽

José Ornelas-Paz ◽

...

Keyword(s):

Aspergillus Nidulans ◽

Phytopathogenic Fungi ◽

Antagonistic Activity ◽

Trichoderma Spp ◽

Penicillium Crustosum ◽

Bacillus Spp

Muchas enfermedades en cultivos causadas por hongos patógenos representan un problema económico debido a las pérdidas que éstas causan. Del mismo modo microorganismos antagonistas tales como Trichoderma spp. y Bacillus spp., entre otros, han sido usados como agentes de control biológico como una alternativa eficiente para reducir el uso de fungicidas químicos en el control de enfermedades de plantas. El objetivo de este estudio fue identificar taxas de microorganismos patógenos y antagonistas basado en sus caracteres moleculares y evaluar la actividad antagónica in vitro de dos aislados de Bacillus y dos aislados de Trichoderma contra cinco hongos patogénicos comunes: Fusarium oxysporum, Botrytis cinerea, Penicillium crustosum, Aspergillus nidulans y Alternaria alternata. Para la identificación molecular, los nueve microorganismos fueron usados para la extracción del ADN genómico y amplificación del gen del ADN ribosomal 18S y del Espaciador Transcrito Interno con los iniciadores ITS (ITS5 e ITS4) para los hongos y el gen del 16S del ADNr, usando los iniciadores universales EU(F) y EU(R) para bacterias. Ambos aislados de T. asperellum mostraron una actividad antagonista significativa contra los hongos fitopatógenos probados, donde los porcentajes de inhibición del crecimiento radial (PICR) de las colonias de hongos fitopatógenos fluctuó de 43 a 71%, mientras los PICR inducidos por Bacillus fueron significativos, con valores de hasta 69% cuando se probaron in vitro contra B. cinerea, mientras que el efecto más bajo se observó con F. oxysporum, P. crustosum y A. nidulans. Ambas especies de Bacillus, indujeron la presencia de un halo de inhibición, con valores de 5 y 11 mm, cuando se probaron in vitro contra F. oxysporum y B. cinerea, respectivamente. Los efectos antagonistas de los aislados de bacterias y hongos, muestran que estos microorganismos pueden ser usados como agentes de control biológico de varios hongos fitopatógenos de cultivos.

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Potato-associated bacteria and their antagonistic potential towards plant-pathogenic fungi and the plant-parasitic nematodeMeloidogyne incognita(Kofoid & White) Chitwood

Canadian Journal of Microbiology ◽

10.1139/w02-071 ◽

2002 ◽

Vol 48 (9) ◽

pp. 772-786 ◽

Cited By ~ 129

Author(s):

Annette Krechel ◽

Annekathrin Faupel ◽

Johannes Hallmann ◽

Andreas Ulrich ◽

Gabriele Berg

Keyword(s):

Fungal Pathogens ◽

Bacterial Species ◽

Pathogenic Fungi ◽

Antagonistic Activity ◽

Polymorphism Analysis ◽

Culturable Bacteria ◽

Streptomyces Species ◽

Associated Bacteria ◽

Antagonistic Potential

To study the effect of microenvironments on potato-associated bacteria, the abundance and diversity of bacteria isolated from the rhizosphere, phyllosphere, endorhiza, and endosphere of field grown potato was analyzed. Culturable bacteria were obtained after plating on R2A medium. The endophytic populations averaged 103and 105CFU/g (fresh wt.) for the endosphere and endorhiza, respectively, which were lower than those for the ectophytic microenvironments, with 105and 107CFU/g (fresh wt.) for the phyllosphere and rhizosphere, respectively. The composition and richness of bacterial species was microenvironment-dependent. The occurrence and diversity of potato-associated bacteria was additionally monitored by a cultivation-independent approach using terminal restriction fragment length polymorphism analysis of 16S rDNA. The patterns obtained revealed a high heterogeneity of community composition and suggested the existence of microenvironment-specific communities. In an approach to measure the antagonistic potential of potato-associated bacteria, a total of 440 bacteria was screened by dual testing for in vitro antagonism towards the soilborne pathogens Verticillium dahliae and Rhizoctonia solani. The proportion of isolates with antagonistic activity was highest for the rhizosphere (10%), followed by the endorhiza (9%), phyllosphere (6%), and endosphere (5%). All 33 fungal antagonists were characterized by testing their in vitro antagonistic mechanisms, including their glucanolytic, chitinolytic, pectinolytic, cellulolytic, and proteolytic activity, and by their BOX-PCR fingerprints. In addition, they were screened for their biocontrol activity against Meloidogyne incognita. Overall, nine isolates belonging to Pseudomonas and Streptomyces species were found to control both fungal pathogens and M. incognita and were therefore considered as promising biological control agents. Key words: biocontrol, antagonistic potential, plant-associated bacteria.

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Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d220136 ◽

2020 ◽

Vol 22 (1) ◽

Author(s):

Yan Ramona ◽

IDA BAGUS GEDE DARMAYASA ◽

ANAK AGUNG NGURAH NARA KUSUMA ◽

Martin Line

Keyword(s):

Fungal Pathogens ◽

Plant Pathogens ◽

Antagonistic Activity ◽

Significant Inhibition ◽

Biocontrol Agents ◽

Dual Culture ◽

Rdna Sequences ◽

Fungal Plant Pathogens ◽

Mature Compost

Abstract. Ramona Y, Darmayasa IBG, Kusuma AANN, Line MA. 2021. Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens. Biodiversitas 22: 298-303. This study investigated the inhibitory potential of diversity of antagonist bacteria residing in the rhizosphere zone and mature compost to counter fungal plant pathogens. Soils collected from rhizosphere of lettuce farms in Bali-Indonesia and Tasmania-Australia, mature compost, commercial biocontrol (Dipel®), and laboratory contaminants with significant inhibition against tested fungal pathogens were used as sources of antagonist bacteria. These antagonists were isolated by applying dilution and spread method on trypticase soya agar (TSA) or potato dextrose agar (PDA), and their ability to inhibit Sclerotinia minor, Sclerotinia sclerotiorum, Fusarium spp., and Rhizoctonia solani was assessed in dual culture assays. The results showed that 67 out of more than 100 isolates had antagonistic activity in vitro against at least one of tested fungal pathogens. In the preliminary identification, Bacillus spp. or Pseudomonas spp. were found to be pre-dominant isolates. Following screening studies in a non-replicated glasshouse experiment against S. minor and S. sclerotiorum, 8 of the most promising isolates were further identified using molecular methods based on their 16s rDNA sequences aligned with those deposited at the GeneBank. These 8 isolates were identified as Pseudomonas corrugata, Bacillus megaterium, Bacillus polymyxa, Bacillus mojavensis, Bacillus pumilus, Bacillus thuringiensis, Exiguobacterium acetylicum, and Chryseobacterium indologenes.

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Antagonistic effect of volatile and non-volatile compounds from Streptomyces strains on cultures of several phytopathogenic fungi

Emirates Journal of Food and Agriculture ◽

10.9755/ejfa.2020.v32.i12.2222 ◽

2020 ◽

pp. 879

Author(s):

Daniel Alonso Pérez Corral ◽

José de Jesús Ornelas Paz ◽

Guadalupe Isela Olivas Orozco ◽

Carlos Horacio Acosta Muñiz ◽

Miguel Ángel Salas Marina ◽

...

Keyword(s):

Volatile Compounds ◽

Fungal Pathogens ◽

Culture Medium ◽

Plant Pathogens ◽

Aerial Mycelium ◽

Phytopathogenic Fungi ◽

Antagonistic Activity ◽

Antagonistic Effect ◽

Fresh Culture Medium

Fungi and oomycetes are important plant pathogens that constantly attacked plants, thus compromising the production of foods worldwide. Streptomyces strains might be useful to control fungal pathogens by different mechanism. The in vitro antagonistic activity of non-volatile and volatile metabolites from four Streptomyces strains was evaluated over cultures of phytopathogenic fungi and oomycetes. The non-volatile compounds from Streptomyces strains significantly reduced (44.2 to 92.1%) the growth of aerial mycelium of pathogens. The volatile compounds (VOCs) from Streptomyces strains reduced both aerial mycelium (22.5 to 96.7%) and mycelium growing inside of culture medium (0.0 - 9.4%). The pathogens maintained their capacity to grow normally in fresh culture medium without antagonists after confrontations with antagonist VOCs. The analysis of VOCs by gas chromatography coupled to mass spectrometry revealed different kinds of VOCs included alcohols, aldehydes, ketones, esters, terpenes, terpenoids, thioethers, among others. The most abundant VOCs were trans-1,10-dimethyl-trans-9-decalol (geosmin), 2-methylisoborneol, 2-methyl-2-bornene, 1,4-dimethyladamantane, and 4-penten-1-ol, trifluoroacetate. The antipathogenic activity of nine pure VOCs that had been identified in cultures of the Streptomyces strains alone was evaluated in vitro against phytopathogenic fungi and oomycetes. Trans-2-hexenal was the most effective of these VOCs, inhibiting completely the growth of tested phytopathogens. The volatile and non-volatile compounds from Streptomyces strains effectively reduced the in vitro growth of phytopathogens and they might be used as biological control. Further studies are required to demonstrate this activity on open field conditions.

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Isolation of antagonistic fungi from rhizospheres and its biocontrol activity against different isolates of soil borne fungal pathogens infected legumes

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d200735 ◽

2019 ◽

Vol 20 (7) ◽

Cited By ~ 1

Author(s):

ERIYANTO YUSNAWAN ◽

ALFI INAYATI ◽

YULIANTORO BALIADI

Keyword(s):

Rhizoctonia Solani ◽

Fungal Pathogens ◽

In Vitro Study ◽

Antagonistic Activity ◽

Dual Culture ◽

Antagonistic Fungi ◽

Biocontrol Activity ◽

Fusarium Sp ◽

Trichoderma Isolates

Abstract. Yusnawan E, Inayati A, Baliadi Y. 2019. Isolation of antagonistic fungi from rhizospheres and its biocontrol activity against different isolates of soil borne fungal pathogens infected legumes. Biodiversitas 20: 2048-2054. Soilborne diseases caused by Rhizoctonia solani and Fusarium sp. are biotic limits for legume production. Biological controls offer environmental friendly control for these pathogens. This study aimed to isolate and screen Trichoderma from different rhizospheres and to obtain effective Trichoderma isolates to suppress in vitro growth of the soil borne pathogens. The antagonistic inhibitory activity was performed by dual culture method. Seven out of forty indigenous Trichoderma isolates collected from East Java, Indonesia effectively suppressed the growth of different fungal isolates, namely Rhizoctonia solani (R.s1), R. solani (R.s2) as well as Fusarium sp. which infected soybean and mung bean. In vitro study showed different suppression of the pathogens on dual culture tests. The seven isolates inhibited the growth of R. solani (R.s1), R.solani (R.s2) and Fusarium sp. ranging from 90.0 to 99.6%, 72.8 to 82.4%, and 67.9 to 90.8%, respectively. Isolate origin and genetic variability of Trichoderma played an important role in the antagonistic activity. The fast-growing of selected Trichoderma showed their abilities for space occupation and nutrition competition, which involved in the antagonistic activity. The mycelial growth of Trichoderma over pathogens showed hyperparasitism mechanism. In addition, coiling of Trichoderma over hyphal pathogens was observed during microscopic observation. The seven Trichoderma isolates, therefore, are promising as biological control agents against the soil borne fungi infected legumes.

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Quantification and assessment of viability of Cryptococcus neoformans by LightCycler amplification of capsule gene mRNA

Journal of Medical Microbiology ◽

10.1099/jmm.0.45742-0 ◽

2004 ◽

Vol 53 (12) ◽

pp. 1201-1206 ◽

Cited By ~ 9

Author(s):

Muhammad Amjad ◽

Najla Kfoury ◽

Raymond Cha ◽

Reem Mobarak

Keyword(s):

Cryptococcus Neoformans ◽

Internal Control ◽

Fungal Pathogens ◽

Pcr Amplification ◽

Plasmid Vector ◽

Antifungal Drugs ◽

Yeast Cells ◽

Rt Pcr ◽

Gene Mrna

Cryptococcus neoformans is an opportunistic fungal pathogen. It infects the central nervous system causing meningitis, which is fatal if untreated, especially in AIDS and immunosuppressed patients. In this study a method of quantification and assessment of viability of C. neoformans by LightCycler RT-PCR amplification of the capsule gene mRNA is established. The sequence of primers and probes were derived from C. neoformans capsular CAP10 gene mRNA (GenBank accession number AF144574), and were species specific. Agarose gel electrophoresis analysis of LightCycler RT-PCR product showed a single band of 223 bp in length. In order to develop an internal control a 223 bp exon fragment of capsule mRNA was cloned in the pCR2.1 plasmid vector and RNA was generated by in vitro transcription. To determine the sensitivity of the assay, serial dilutions of in vitro-transcribed RNA with known concentrations and copy numbers, and serially diluted cultures of viable and nonviable C. neoformans were used. Under optimal conditions as little as 0.472 fg of capsule mRNA could be detected, corresponding to 1–10 c.f.u. ml−1 of the sample. No amplification was observed from up to105 heat/UV radiation-killed yeast cells and RNA of other bacterial and fungal pathogens and human genomic DNA or RNA. The amplification of capsule mRNA represents a sensitive, specific and quantitative means of detection of viable C. neoformans in clinical specimens and can be useful in the evaluation of the therapeutic efficacy of antifungal drugs in the treatment of C. neoformans meningitis.

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Biological Control of Fruit Rot and Anthracnose of Postharvest Mango by Antagonistic Yeasts from Economic Crops Leaves

Microorganisms ◽

10.3390/microorganisms8030317 ◽

2020 ◽

Vol 8 (3) ◽

pp. 317 ◽

Cited By ~ 4

Author(s):

Wilasinee Konsue ◽

Tida Dethoup ◽

Savitree Limtong

Keyword(s):

Biological Control ◽

Fungal Pathogens ◽

Effective Strain ◽

Fruit Rot ◽

Yeast Cells ◽

Mango Fruit ◽

Yeast Strains ◽

Volatile Organic ◽

Pseudozyma Hubeiensis

To select antagonistic yeasts for the control of fruit rot caused by Lasiodiplodia theobromae and anthracnose caused by Colletotrichum gloeosporioides in postharvest mango fruit, 307 yeast strains isolated from plant leaves were evaluated for their antagonistic activities against these two fungal pathogens in vitro. Torulaspora indica DMKU-RP31, T. indica DMKU-RP35 and Pseudozyma hubeiensis YE-21 were found to inhibit the growth of L. theobromae whereas only Papiliotrema aspenensis DMKU-SP67 inhibited the growth of C. gloeosporioides. Antagonistic mechanisms of these four antagonistic yeasts in vitro consisted of the production of antifungal volatile organic compounds (VOCs), biofilm formation and siderophore production. T. indica DMKU-RP35 was the most effective strain in controlling fruit rot on postharvest mango fruits. Its action was comparable to that of the fungicide, benomyl, reducing the disease severity by 82.4%, whereas benomyl revealed 87.5% reduction. P. aspenensis DMKU-SP67 reduced anthracnose severity by 94.1%, which was comparable to that of using benomyl (93.9%). The antifungal VOCs produced by these yeast strains also reduced the severity of these diseases on postharvest mango fruits but at lower rates than using yeast cells. Therefore, these antagonistic yeasts have the potential for use as biological control agents for the control of fruit rot and anthracnose diseases.

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Screening and Identification of Yeasts Antagonistic to Pathogenic Fungi Show a Narrow Optimal pH Range for Antagonistic Activity

Polish Journal of Microbiology ◽

10.5604/17331331.1234997 ◽

2017 ◽

Vol 66 (1) ◽

pp. 101-106 ◽

Cited By ~ 4

Author(s):

Pei-Hua Chen ◽

Jui-Yu Chou

Keyword(s):

Interference Competition ◽

Pathogenic Fungi ◽

Antagonistic Activity ◽

Yeast Cells ◽

Yeast Strains ◽

Screening And Identification ◽

Ustilago Esculenta ◽

Ph Range ◽

Pichia Kluyveri ◽

Optimal Ph

Microbes have evolved ways of interference competition to gain advantage over their ecological competitors. The use of secreted antagonistic compounds by yeast cells is one of the prominent examples. Although this killer behavior has been thoroughly studied in laboratory yeast strains, our knowledge of the antagonistic specificity of killer effects in nature remains limited. In this study, yeast strains were collected from various niches and screened for antagonistic activity against one toxin-sensitive strain of Saccharomyces cerevisiae and three pathogenic fungi. We demonstrate that some strains with antagonistic activity against these pathogenic fungi can be found in antagonist culture tests. These yeasts were identified as members of Trichosporon asahii, Candida stellimalicola, Wickerhamomyces anomalus, Ustilago esculenta, Aureobasidium pullulans, and Pichia kluyveri. The results indicated that the antagonistic activity of these killer yeasts has a narrow optimal pH range. Furthermore, we found that the antagonistic activity of some species is strain-dependent.

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The enigmatic role of fungal annexins: the case of Cryptococcus neoformans

10.1101/536193 ◽

2019 ◽

Author(s):

Maria Maryam ◽

Man Shun Fu ◽

Alexandre Alanio ◽

Emma Camacho ◽

Diego S. Goncalves ◽

...

Keyword(s):

Cryptococcus Neoformans ◽

Fungal Pathogens ◽

Cell Function ◽

Model Organism ◽

Fungal Species ◽

Yeast Cells ◽

Dependent Manner ◽

Membrane Repair

AbstractAnnexins are multifunctional proteins that bind to phospholipid membranes in a calcium-dependent manner. Annexins play a myriad of critical and well-characterized roles in mammals, ranging from membrane repair to vesicular secretion. The role of annexins in the kingdoms of bacteria, protozoa and fungi have been largely overlooked. The fact that there is no known homologue of annexins in the model organism may contribute to this gap in knowledge. However, annexins are found in most medically important fungal pathogens, with the notable exception of Candida albicans. In this study we evaluated the function of the one annexin gene in Cryptococcus neoformans, a causative agent of cryptococcosis. This gene CNAG_02415, is annotated in the C. neoformans genome as a target of calcineurin through its transcription factor Crz1, and we propose to update its name to cryptococcal annexin, AnnexinC1. C. neoformans strains deleted for AnnexinC1 revealed no difference in survival after exposure to various chemical stressor relative the wild type, as well as no major alteration in virulence or mating. The only alteration observed in strains deleted for AnnexinC1 was a small increase in the titan cells formation in vitro. The preservation of annexins in many different fungal species suggests an important function, and therefore the lack of a strong phenotype for annexin-deficient C. neoformans is suggestive of either redundant genes that can compensate for the absence of AnnexinC1 function or novel functions not revealed by standard assays of cell function and pathogenicity.ImportanceCryptococcus neoformans is the deadliest human fungal pathogen, causing almost 200,000 deaths each year. Treatment of this lethal infection is lengthy, and in some patients therapy is not curative and patients require lifelong therapy. Fundamental research in this yeast is needed so that we can understand mechanisms of infection and disease and ultimately devise better therapies. In this work we investigated a fungal representative of the annexin family of proteins, specifically in the context of virulence and mating. We find that the cryptococcal annexin does not seem to be involved in virulence or mating but affects generation of titan cells, enlarged yeast cells that are detected in the lungs of mammalian hosts. Our data provides new knowledge in an unexplored area of fungal biology.

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