scholarly journals Mycoviral Population Dynamics in Spanish Isolates of the Entomopathogenic Fungus Beauveria bassiana

Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 665 ◽  
Author(s):  
Charalampos Filippou ◽  
Inmaculada Garrido-Jurado ◽  
Nicolai Meyling ◽  
Enrique Quesada-Moraga ◽  
Robert Coutts ◽  
...  
Keyword(s):  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Insect Pests ◽  
Fruit Fly ◽  
Population Diversity ◽  
Viral Genomes ◽  
Large Panels ◽  
High Virulence ◽  
Fungus Beauveria Bassiana ◽  
Rna Polymerase Gene

The use of mycoviruses to manipulate the virulence of entomopathogenic fungi employed as biocontrol agents may lead to the development of novel methods to control attacks by insect pests. Such approaches are urgently required, as existing agrochemicals are being withdrawn from the market due to environmental and health concerns. The aim of this work is to investigate the presence and diversity of mycoviruses in large panels of entomopathogenic fungi, mostly from Spain and Denmark. In total, 151 isolates belonging to the genera Beauveria, Metarhizium, Lecanicillium, Purpureocillium, Isaria, and Paecilomyces were screened for the presence of dsRNA elements and 12 Spanish B. bassiana isolates were found to harbor mycoviruses. All identified mycoviruses belong to three previously characterised species, the officially recognised Beauveria bassiana victorivirus 1 (BbVV-1) and the proposed Beauveria bassiana partitivirus 2 (BbPV-2) and Beauveria bassiana polymycovirus 1 (BbPmV-1); individual B. bassiana isolates may harbor up to three of these mycoviruses. Notably, these mycovirus species are under distinct selection pressures, while recombination of viral genomes increases population diversity. Phylogenetic analysis of the RNA-dependent RNA polymerase gene sequences revealed that the current population structure in Spain is potentially a result of both vertical and horizontal mycovirus transmission. Finally, pathogenicity experiments using the Mediterranean fruit fly Ceratitis capitata showed no direct correlation between the presence of any particular mycovirus and the virulence of the B. bassiana isolates, but illustrated potentially interesting isolates that exhibit relatively high virulence, which will be used in more detailed virulence experimentation in the future.

scholarly journals Alternative substrates for conidiogenesis of the entomopathogenic fungus Beauveria bassiana (Bals) Vuillemin (Deuteromycotina: Hyphomycetes)

2020 ◽  
Vol 80 (1) ◽  
pp. 133-141
Author(s):  
A. G. L. Paiva-Guimarães ◽  
K. R. L. Freire ◽  
S. F. M. Santos ◽  
A. F. Almeida ◽  
A.C.B. Sousa
Keyword(s):  
Biological Control ◽  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Insecticidal Activity ◽  
Insect Pests ◽  
Low Cost ◽  
Nutritional Supplement ◽  
Conidia Production ◽  
Fungus Beauveria Bassiana ◽  
Potential Use

Abstract Beauveria bassiana is a promising fungus for the biological control of insect pests. The growing costs of conidia production have raised the need to ascertain the efficiency of some low cost substrates. The aim of this study was to analyze the potential use of different raw substrates without nutritional supplement for B. bassiana conidiogenesis. Growth and sporulation were evaluated using 30 g of substrate and 0.3 μL of a conidia suspension (1 x 106 conidia/mL). After 10 days of incubation (70 ± 10% humidity and temperature (T) = 29 ± 1 °C), rice (2.00 x 106 conidia/g substrate), algaroba (2.36 x 106 conidia/g), malt A (1.22 x 106 conidia/g) and malt B (1.75 x 106 conidia/g) showed the highest levels of conidia production. The resulting conidia showed insecticidal activity higher than 80% on coconut termites. These new raw substrates may represent viable alternatives for the production of entomopathogenic fungi for use in the biological control of various insect pests.

scholarly journals Increased Insect Virulence in Beauveria bassiana Strains Overexpressing an Engineered Chitinase

2006 ◽  
Vol 73 (1) ◽  
pp. 295-302 ◽  
Author(s):  
Yanhua Fan ◽  
Weiguo Fang ◽  
Shujuan Guo ◽  
Xiaoqiong Pei ◽  
Yongjun Zhang ◽  
...  
Keyword(s):  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Insect Pests ◽  
Hydrolytic Enzymes ◽  
Binding Domain ◽  
Constitutive Promoter ◽  
Chitin Binding Domain ◽  
Time To Death ◽  
Binding Domains ◽  
Genetic Components

ABSTRACT Entomopathogenic fungi are currently being used for the control of several insect pests as alternatives or supplements to chemical insecticides. Improvements in virulence and speed of kill can be achieved by understanding the mechanisms of fungal pathogenesis and genetically modifying targeted genes, thus improving the commercial efficacy of these biocontrol agents. Entomopathogenic fungi, such as Beauveria bassiana, penetrate the insect cuticle utilizing a plethora of hydrolytic enzymes, including chitinases, which are important virulence factors. Two chitinases (Bbchit1 and Bbchit2) have previously been characterized in B. bassiana, neither of which possesses chitin-binding domains. Here we report the construction and characterization of several B. bassiana hybrid chitinases where the chitinase Bbchit1 was fused to chitin-binding domains derived from plant, bacterial, or insect sources. A hybrid chitinase containing the chitin-binding domain (BmChBD) from the silkworm Bombyx mori chitinase fused to Bbchit1 showed the greatest ability to bind to chitin compared to other hybrid chitinases. This hybrid chitinase gene (Bbchit1-BmChBD) was then placed under the control of a fungal constitutive promoter (gpd-Bbchit1-BmChBD) and transformed into B. bassiana. Insect bioassays showed a 23% reduction in time to death in the transformant compared to the wild-type fungus. This transformant also showed greater virulence than another construct (gpd-Bbchit1) with the same constitutive promoter but lacking the chitin-binding domain. We utilized a strategy where genetic components of the host insect can be incorporated into the fungal pathogen in order to increase host cuticle penetration ability.

Different strategies to kill the host presented byMetarhizium anisopliaeandBeauveria bassiana

2018 ◽  
Vol 64 (3) ◽  
pp. 191-200 ◽  
Author(s):  
Cynthia Barbosa Rustiguel ◽  
María Fernández-Bravo ◽  
Luis Henrique Souza Guimarães ◽  
Enrique Quesada-Moraga
Keyword(s):  
Secondary Metabolites ◽  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Metarhizium Anisopliae ◽  
Galleria Mellonella ◽  
Insect Pests ◽  
Fungal Growth ◽  
Growth Strategy

Studies conducted over the last decades have shown the potential of entomopathogenic fungi for the biocontrol of some insect pests. Entomopathogenic fungi infect their host through the cuticle, so they do not need to be ingested to be effective. These fungi also secrete secondary metabolites and proteins that are toxic to insect pests. In this context, we analyzed the pathogenicity of Metarhizium anisopliae (Metschn.) strains IBCB 384 and IBCB 425 and Beauveria bassiana (Bals.-Criv.) Vuill. strains E 1764 and E 3158 against Galleria mellonella (Linn.) larvae, during pre-invasion and post-invasion phases. The results showed M. anisopliae, especially strain IBCB 384, was most virulent in the pre-invasion phase against G. mellonella, whereas B. bassiana, especially strain E 1764, was most virulent in the post-invasion phase. During in vivo development and in the production of toxic serum, B. bassiana E 3158 was the most virulent. Different fungal growth (or toxin) strategies were observed for studied strains. Metarhizium anisopliae IBCB 425 prioritizes the growth strategy, whereas strain IBCB 384 and B. bassiana strains E 1764 and E 3158 have a toxic strategy. All strains have pathogenicity against G. mellonella, indicating their possible use for biocontrol.

scholarly journals Entomopathogenic fungi of soils of freshwater swamps, tidal lowlands, peatlands, and highlands of South Sumatra, Indonesia

2018 ◽  
Vol 19 (6) ◽  
pp. 2365-2373 ◽  
Author(s):  
AYU SAFITRI ◽  
SITI HERLINDA ◽  
ARUM SETIAWAN
Keyword(s):  
Biological Control ◽  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Metarhizium Anisopliae ◽  
Insect Pests ◽  
Vegetation Type ◽  
Tenebrio Molitor ◽  
Soil Samples ◽  
Fungal Isolates

Safitri A, Herlinda S, Setiawan A. 2018. Entomopathogenic fungi of soils of freshwater swamps, tidal lowlands, peatlands, and highlands of South Sumatra, Indonesia. Biodiversitas 19: 2365-2373. Ecosystems of lowlands and highlands in South Sumatra have specific characteristics of soils and vegetations that can affect the availability of entomopathogenic fungi. This study aimed to explore and identify species and to determine inoculum potentials of the entomopathogenic fungi from soils of freshwater swamps, tidal lowlands, peatlands, and highlands. Baiting of entomopathogenic fungi on soil samples used the larvae of Tenebrio molitor. The entomopathogenic fungi species found in this research were Beauveria bassiana and Metarhizium anisopliae. The number of the fungal isolates were 30 isolates consisting of nine isolates of B. bassiana and 21 isolates of M. anisopliae.The highest number of isolates was found in the highland ecosystem (11 isolates) and the lowest was found in peatland ecosystem (4 isolates). The highest percentage average of inoculum potentials of the fungi was found in the high land ecosystem (4.04%) and the lowest one was found in freshwater swamps ecosystem (2.11%). Based on the vegetation type, the soil planted with mustard in Talang Patai-Pagaralam (highland ecosystem) had the highest inoculum potentials (9.33%). These fungi will make an important contribution to the biological control for insect pests in lowland to highland ecosystems in Indonesia.

scholarly journals Lipidomic response of the entomopathogenic fungus Beauveria bassiana to pyrethroids

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Litwin ◽  
Przemysław Bernat ◽  
Monika Nowak ◽  
Mirosława Słaba ◽  
Sylwia Różalska
Keyword(s):  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Neutral Lipids ◽  
Sodium Content ◽  
Cellular Level ◽  
Cell Membrane Permeability ◽  
Environmentally Safe ◽  
Membrane Changes ◽  
Fungus Beauveria Bassiana ◽  
Phospholipid Profile

AbstractPyrethroids are chemical insecticides that are widely used to control pests. Entomopathogenic fungi are considered environmentally safe alternatives to these compounds. Pyrethroids and entomopathogenic fungi not only co-exist in the environment but can also be applied together in pest control. They are often found in contact with each other, and thus, it seems important to understand their interactions at the cellular level. In this study, we analyzed whether pyrethroids could influence the phospholipid profile of Beauveria bassiana and whether membrane changes are one of the mechanisms by which these fungi adapt to unfavorable environmental conditions. The results of our study revealed that pyrethroids changed the phospholipid profile and increased the cell membrane permeability of B. bassiana, which enabled them to enter and accumulate within the fungal cells, resulting in oxidative stress. Pyrethroids influenced the amount of neutral lipids, caused a decrease in sodium content, and also temporarily lowered the level of the secondary metabolite oosporein in the studied fungi. These findings indicate that the effect of pyrethroids on entomopathogenic fungi may be more complex than originally thought and that lipidomic studies can aid in fully understanding the influence of these chemicals on the mentioned group of fungi.

Virulence of Some Entomopathogenic Fungi Isolates of Beauveria bassiana (Hypocreales: Cordycipitaceae) and Metarhizium anisopliae (Hypocreales: Clavicipitaceae) to Aulacaspis tubercularis (Hemiptera: Diaspididae)and Icerya seychellarum (Hemiptera: Monophlebidae) on Mango Crop

2019 ◽  
Author(s):  
Atef M M Sayed ◽  
Christopher A Dunlap
Keyword(s):  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Metarhizium Anisopliae ◽  
Insect Pests ◽  
Microbial Control ◽  
Probit Analysis ◽  
Scale Insects ◽  
Elapsed Time ◽  
Fungal Isolates ◽  
Further Development

Abstract Six fungal isolates of Beauveria bassiana (Balsamo) Vuillemin and one isolate of Metarhizium anisopliae (Metschnikoff) Sorokin were isolated and evaluated for their pathogenicity to Icerya seychellarum (Westwood) and Aulacaspis tubercularis Newstead. There is a positive correlation between the concentration of the fungal blastospore concentrations and the percentage of mortality. Bio-efficacy increased significantly after inoculation with increasing concentration of blastospores and elapsed time up to 12 d after inoculation. The mortality of nymphs exposed to fungal isolates at various concentrations varied between 2.5 and 88.8%. Probit analysis of data at 95% confidence limits of LC50 and LT50s showed significant differences in the susceptibility of nymphs of I. seychellarum and A. tubercularis to the tested fungal isolates. The fungal isolates of Egy-6 and Egy-9 were the most effective against I. seychellarum and A. tubercularis, respectively. They had the lowest LC50 (4.20 × 105 and 5.71 × 103 blastospore ml−1) and LT50 (ranged from 4.61 to 9.79 and 4.84 to 8.71 d), respectively. The current study showed that all the fungal isolates yielded moderate mortality rates of nymphs and adult female populations of both the tested insect pests. To our knowledge, this is the first report of bio-efficacy of Beauveria and Metarhizium isolates against members of the Diaspidadae and Monophlebidae family insects. These results establish that the use of these native entomopathogenic fungi isolates of B. bassiana (Egy-3, Egy-4, Egy-6, Egy-7, Egy-9, and Egy-10) and M. anisopliae (Egy-5) could be considered for further development as microbial control agents of the mealybug and scale insects as a potential biological agent for use in an IPM program.

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