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Mark A Jackson - One of the best experts on this subject based on the ideXlab platform.
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Nitrogen sources affect productivity, desiccation tolerance and storage stability of Beauveria bassiana Blastospores
Journal of applied microbiology, 2018Co-Authors: Gabriel Moura Mascarin, Mark A Jackson, Nilce Naomi Kobori, Christopher A Dunlap, Italo DelaliberaAbstract:AIMS Nitrogen is a critical element in industrial fermentation media. This study investigated the influence of various nitrogen sources on blastospore production, desiccation tolerance and storage stability using two strains of the cosmopolitan insect-pathogenic fungus Beauveria bassiana. METHODS AND RESULTS Complex organic sources of nitrogen such as soy flour, autolysed yeast and cottonseed flour induced great numbers of Blastospores after 2-3 days of fermentation, which also survived drying and remained viable (32-56% survival) after 9 months storage at 4°C, although variations were found between strains. Nitrogen availability in the form of free amino acids directly influenced blastospore production and resistance to desiccation. Increasing glucose and nitrogen concentrations up to 120 and 30 g l-1 , respectively, did not improve blastospore production but enhanced desiccation tolerance. Cell viability after drying and upon fast-rehydration was increased when ≥25 g acid-hydrolysed casein per litre was supplemented in the liquid culture medium. CONCLUSIONS These findings indicate that low-cost complex nitrogen compounds are suitable to enhance yeast-like growth by B. bassiana with good desiccation tolerance and therefore support its further scale-up production as a mycoinsecticide. SIGNIFICANCE AND IMPACT OF THE STUDY Nitrogen is the most expensive nutrient in liquid media composition, but this study underscores the feasibility of using low-cost nitrogen compounds composed mainly of agro-industrial by-products for rapid production of desiccation-tolerant B. bassiana Blastospores by liquid culture fermentation.
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oviposition behavior and survival of tamarixia radiata hymenoptera eulophidae an ectoparasitoid of the asian citrus psyllid diaphorina citri hemiptera liviidae on hosts exposed to an entomopathogenic fungus isaria fumosorosea hypocreales cordycipitac
Journal of Economic Entomology, 2016Co-Authors: Andrew Chow, Joseph M Patt, Mark A Jackson, Christopher A Dunlap, Daniel Flores, Mamoudou SetamouAbstract:Antagonistic interactions between the nymphal parasitoid, Tamarixia radiata Waterston (Hymenoptera: Eulophidae), and the ARSEF 3581 strain of the entomopathogenic fungus, Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae), could disrupt biological control of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Three interactions were evaluated under laboratory conditions at 25 °C: 1) parasitoid survival if parasitized hosts were exposed to ARSEF 3581 Blastospores before or after host mummification; 2) parasitoid survival if mummies containing larva or pupa were exposed to ARSEF 3581 hyphae; 3) parasitoid oviposition on infected hosts with visible or without visible hyphae. Topical application of blastospore formulation onto the dorsal surfaces of live nymphs parasitized with second-instar wasp larva (3 d after parasitism) reduced host mummification by 50% and parasitoid emergence by 85%. However, parasitoid emergence was not affected by topical application of blastospore formulation onto mummies that contained fourth-instar wasp larva (6 d after parasitism). Parasitoid emergence was reduced by 80% if mummies containing fourth-instar wasp larva were covered with blastospore formulation colonized by fungal hyphae. In comparison, parasitoid emergence was not affected if mummies containing wasp pupa (9 d after parasitism) were covered with formulation colonized by fungal hyphae. Female parasitoids oviposited on infected hosts without visible hyphae but not on infected hosts with visible hyphae. Our findings suggest that I. fumosorosea could detrimentally affect T. radiata , if both natural enemies are simultaneously deployed for biological control of D. citri . However, temporal separation of the fungus and parasitoid could reduce antagonism and enhance control of D. citri .
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improved shelf life of dried beauveria bassiana Blastospores using convective drying and active packaging processes
Applied Microbiology and Biotechnology, 2016Co-Authors: Robert W Behle, Mark A Jackson, Nilce Naomi Kobori, Gabriel Moura Mascarin, Italo DelaliberaAbstract:The yeast form (blastospore) of the dimorphic insect-pathogenic fungus Beauveria bassiana can be rapidly produced using liquid fermentation methods but is generally unable to survive rapid dehydration processes or storage under non-refrigerated conditions. In this study, we evaluated the influence of two convective drying methods, various modified atmosphere packaging systems, and storage temperatures on the desiccation tolerance, storage stability, and virulence of Blastospores of B. bassiana ESALQ 1432. All blastospore formulations were dried to <5 % water content equivalent to aw < 0.3. The viability of B. bassiana Blastospores after air drying and spray drying was greater than 80 %. Vacuum-packaged Blastospores remained viable longer when stored at 4 °C compared with 28 °C with virtually no loss in viability over 9 months regardless the drying method. When both oxygen and moisture scavengers were added to sealed packages of dried blastospore formulations stored at 28 °C, viability was significantly prolonged for both air- and spray-dried Blastospores. The addition of ascorbic acid during spray drying did not improve desiccation tolerance but enhanced cell stability (∼twofold higher half-life) when stored at 28 °C. After storage for 4 months at 28 °C, air-dried Blastospores produced a lower LC80 and resulted in higher mortality to whitefly nymphs (Bemisia tabaci) when compared with spray-dried Blastospores. These studies identified key storage conditions (low aw and oxygen availability) that improved blastospore storage stability at 28 °C and will facilitate the commercial development of Blastospores-based bioinsecticides.
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efficacy of an autodisseminator of an entomopathogenic fungus isaria fumosorosea to suppress asian citrus psyllid diaphorina citri under greenhouse conditions
Biological Control, 2015Co-Authors: Joseph M Patt, Pasco B. Avery, Mark A Jackson, Christopher A Dunlap, Andrew Chow, Daniel Flores, Mamoudou Setamou, William G Meikle, Carlos Gracia, Wayne B. HunterAbstract:Abstract We are developing an autodisseminator (‘dispenser’) to inoculate Asian citrus psyllid with entomopathogens for the purpose of inducing epizootics in residential trees and abandoned groves, areas where chemical control is problematic. The dispenser prototype consisted of a bright yellow pleated tube coated with a spore formulation made from pulverized cotton burrs and Blastospores of Isaria fumosorosea . Adult psyllids were released within an array of dispensers and potted citrus saplings in a greenhouse. After 24 h, they were collected from the foliage, surface sterilized, and placed in an incubator. A mean of 55% of the adults developed mycosis ( n = 3 tests), demonstrating that the dispensers could cause primary infection. The potted plants used in the horizontal transmission tests were infested with immature psyllids; 27–35% of which became infected following contact with adults that had visited the dispensers ( n = 2 tests). When mycosed adult cadavers with mature conidia were placed near immatures on the potted plants, over 90% of the immatures mycosed, indicating that conidia from the cadavers were highly contagious. On dispensers left in the greenhouse for three weeks, the infectivity of Blastospores exposed to direct sunlight decreased by 46% after 7 d and by 60% after 20 d, while infectivity levels remained high in Blastospores that were shaded. These results confirmed that that the basic dispenser design was sound with respect to attracting and infecting psyllids. It requires further modification to work effectively under ambient conditions, since exposure to direct sunlight decreased blastospore infectiveness over time.
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Glucose concentration alters dissolved oxygen levels in liquid cultures of Beauveria bassiana and affects formation and bioefficacy of Blastospores
Applied Microbiology and Biotechnology, 2015Co-Authors: Gabriel Moura Mascarin, Robert W Behle, Mark A Jackson, Nilce Naomi Kobori, Christopher A Dunlap, Ítalo Delalibera JúniorAbstract:The filamentous fungus Beauveria bassiana is an economically important pathogen of numerous arthropod pests and is able to grow in submerged culture as filaments (mycelia) or as budding yeast-like Blastospores. In this study, we evaluated the effect of dissolved oxygen and high glucose concentrations on blastospore production by submerged cultures of two isolates of B. bassiana , ESALQ1432 and GHA. Results showed that maintaining adequate dissolved oxygen levels coupled with high glucose concentrations enhanced blastospore yields by both isolates. High glucose concentrations increased the osmotic pressure of the media and coincided with higher dissolved oxygen levels and increased production of significantly smaller Blastospores compared with Blastospores produced in media with lower concentrations of glucose. The desiccation tolerance of Blastospores dried to less than 2.6 % moisture was not affected by the glucose concentration of the medium but was isolate dependent. Blastospores of isolate ESALQ1432 produced in media containing 140 g glucose L^−1 showed greater virulence toward whitefly nymphs ( Bemisia tabaci ) as compared with Blastospores produced in media containing 40 g glucose L^−1. These results suggest a synergistic effect between glucose concentration and oxygen availability on changing morphology and enhancing the yield and efficacy of Blastospores of B. bassiana , thereby facilitating the development of a cost-effective production method for this blastospore-based bioinsecticide.
Christopher A Dunlap - One of the best experts on this subject based on the ideXlab platform.
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transcriptional responses of beauveria bassiana Blastospores cultured under varying glucose concentrations
Frontiers in Cellular and Infection Microbiology, 2021Co-Authors: Gabriel Moura Mascarin, Italo Delalibera, Natasha Sant Anna Iwanicki, Jose Luis Ramirez, Christopher A DunlapAbstract:Culturing the entomopathogenic fungus, Beauveria bassiana, under high glucose concentrations coupled with high aeration results in a fungal developmental shift from hyphal growth to mostly Blastospores (yeast-like cells). The underlying molecular mechanisms involved in this shift remain elusive. A systematic transcriptome analysis of the differential gene expression was preformed to uncover the fungal transcriptomic response to osmotic and oxidative stresses associated with the resulting high blastospore yield. Differential gene expression was compared under moderate (10% w/v) and high (20% w/v) glucose concentrations daily for three days. The RNAseq-based transcriptomic results depicted a higher proportion of downregulated genes when the fungus was grown under 20% glucose than 10%. Additional experiments explored a broader glucose range (4, 8, 12, 16, 20% w/v) with phenotype assessment and qRT-PCR transcript abundance measurements of selected genes. Antioxidant, calcium transport, conidiation, and osmosensor-related genes were highly upregulated in higher glucose titers (16-20%) compared to growth in lower glucose (4-6%) concentrations. The class 1 hydrophobin gene (Hyd1) was highly expressed throughout the culturing. Hyd1 is known to be involved in spore coat rodlet layer assembly, and indicates that Blastospores or another cell type containing hydrophobin 1 is expressed in the haemocoel during the infection process. Furthermore, we found implications of the HOG signaling pathway with upregulation of homologous genes Ssk2 and Hog1 for all fermentation time points under hyperosmotic medium (20% glucose). These findings expand our knowledge of the molecular mechanisms behind blastospore development and may help facilitate large-scale industrial production of B. bassiana Blastospores for pest control applications.
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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 monophlebida
Journal of Economic Entomology, 2019Co-Authors: Atef M M Sayed, Christopher A DunlapAbstract:: 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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Nitrogen sources affect productivity, desiccation tolerance and storage stability of Beauveria bassiana Blastospores
Journal of applied microbiology, 2018Co-Authors: Gabriel Moura Mascarin, Mark A Jackson, Nilce Naomi Kobori, Christopher A Dunlap, Italo DelaliberaAbstract:AIMS Nitrogen is a critical element in industrial fermentation media. This study investigated the influence of various nitrogen sources on blastospore production, desiccation tolerance and storage stability using two strains of the cosmopolitan insect-pathogenic fungus Beauveria bassiana. METHODS AND RESULTS Complex organic sources of nitrogen such as soy flour, autolysed yeast and cottonseed flour induced great numbers of Blastospores after 2-3 days of fermentation, which also survived drying and remained viable (32-56% survival) after 9 months storage at 4°C, although variations were found between strains. Nitrogen availability in the form of free amino acids directly influenced blastospore production and resistance to desiccation. Increasing glucose and nitrogen concentrations up to 120 and 30 g l-1 , respectively, did not improve blastospore production but enhanced desiccation tolerance. Cell viability after drying and upon fast-rehydration was increased when ≥25 g acid-hydrolysed casein per litre was supplemented in the liquid culture medium. CONCLUSIONS These findings indicate that low-cost complex nitrogen compounds are suitable to enhance yeast-like growth by B. bassiana with good desiccation tolerance and therefore support its further scale-up production as a mycoinsecticide. SIGNIFICANCE AND IMPACT OF THE STUDY Nitrogen is the most expensive nutrient in liquid media composition, but this study underscores the feasibility of using low-cost nitrogen compounds composed mainly of agro-industrial by-products for rapid production of desiccation-tolerant B. bassiana Blastospores by liquid culture fermentation.
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Mosquito infection by diverse fungal strains.
2018Co-Authors: José L. Ramirez, Christopher A Dunlap, Ephantus J. Muturi, Ana B. F. Barletta, Alejandro P. RooneyAbstract:(A) Survival curves of fungal-challenged mosquitoes. Graph represents 3 independent experiments and data was analyzed with Log-rank Test (GraphPad Prism 7) (B) Entomopathogenic fungi infection stages: conidia (top), hemocytes and Blastospores (middle), and hyphal growth on mosquito cadavers (bottom). Black arrows indicate hemocytes while red arrows indicate Blastospores. No Blastospores were found in T. roseum-challenged mosquitoes.
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oviposition behavior and survival of tamarixia radiata hymenoptera eulophidae an ectoparasitoid of the asian citrus psyllid diaphorina citri hemiptera liviidae on hosts exposed to an entomopathogenic fungus isaria fumosorosea hypocreales cordycipitac
Journal of Economic Entomology, 2016Co-Authors: Andrew Chow, Joseph M Patt, Mark A Jackson, Christopher A Dunlap, Daniel Flores, Mamoudou SetamouAbstract:Antagonistic interactions between the nymphal parasitoid, Tamarixia radiata Waterston (Hymenoptera: Eulophidae), and the ARSEF 3581 strain of the entomopathogenic fungus, Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae), could disrupt biological control of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Three interactions were evaluated under laboratory conditions at 25 °C: 1) parasitoid survival if parasitized hosts were exposed to ARSEF 3581 Blastospores before or after host mummification; 2) parasitoid survival if mummies containing larva or pupa were exposed to ARSEF 3581 hyphae; 3) parasitoid oviposition on infected hosts with visible or without visible hyphae. Topical application of blastospore formulation onto the dorsal surfaces of live nymphs parasitized with second-instar wasp larva (3 d after parasitism) reduced host mummification by 50% and parasitoid emergence by 85%. However, parasitoid emergence was not affected by topical application of blastospore formulation onto mummies that contained fourth-instar wasp larva (6 d after parasitism). Parasitoid emergence was reduced by 80% if mummies containing fourth-instar wasp larva were covered with blastospore formulation colonized by fungal hyphae. In comparison, parasitoid emergence was not affected if mummies containing wasp pupa (9 d after parasitism) were covered with formulation colonized by fungal hyphae. Female parasitoids oviposited on infected hosts without visible hyphae but not on infected hosts with visible hyphae. Our findings suggest that I. fumosorosea could detrimentally affect T. radiata , if both natural enemies are simultaneously deployed for biological control of D. citri . However, temporal separation of the fungus and parasitoid could reduce antagonism and enhance control of D. citri .
Gabriel Moura Mascarin - One of the best experts on this subject based on the ideXlab platform.
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development of novel spray dried and air dried formulations of metarhizium robertsii Blastospores and their virulence against dalbulus maidis
Applied Microbiology and Biotechnology, 2021Co-Authors: Natasha Sant Anna Iwanicki, Gabriel Moura Mascarin, Sara Giro Moreno, Jørgen Eilenberg, Italo DelaliberaAbstract:The present research addressed spray-drying and air-drying techniques applied to Metarhizium robertsii Blastospores to develop wettable powder (WP) formulations. We investigated the effect of co-formulants on blastospore viability during drying and assessed the wettability and stability of formulations in water. The effect of oxygen-moisture absorbers was studied on the shelf life of these formulations stored at 26 °C and 4 °C for up to 90 days. Additionally, we determined the virulence of the best spray-dried and air-dried formulations against the corn leafhopper Dalbulus maidis. While sucrose and skim milk played an essential role as osmoprotectants in preserving air-dried Blastospores, maltodextrin, skim milk, and bentonite were crucial to attain high cell survival during spray drying. The lowest wettability time was achieved with spray-dried formulations containing less Ca-lignin, while charcoal powder amount was positively associated with formulation stability. The addition of oxygen-moisture absorbers inside sealed packages increased from threefold to fourfold the half-life times of air-dried and spray-dried formulations at both storage temperatures. However, the half-life times of all blastospore-based formulations were shorter than 3 months regardless of temperature and packaging system. Spray-dried and air-dried WP formulations were as virulent as fresh blastopores against D. maydis adults sprayed with 5 × 107 Blastospores mL−1 that induced 87.8% and 70.6% mortality, respectively. These findings bring innovative advancement for M. robertsii blastospore formulation through spray-drying and underpin the importance of adding protective matrices coupled to oxygen-moisture absorbers to extend cell viability during either cold or non-refrigerated storage. • Cost-effective wettable powder formulations of M. robertsii Blastospores were developed. • Bioefficacy of formulations against the corn leafhopper was comparable to fresh Blastospores. • Cold storage and dual oxygen-moisture absorber are critical for extended shelf life.
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transcriptional responses of beauveria bassiana Blastospores cultured under varying glucose concentrations
Frontiers in Cellular and Infection Microbiology, 2021Co-Authors: Gabriel Moura Mascarin, Italo Delalibera, Natasha Sant Anna Iwanicki, Jose Luis Ramirez, Christopher A DunlapAbstract:Culturing the entomopathogenic fungus, Beauveria bassiana, under high glucose concentrations coupled with high aeration results in a fungal developmental shift from hyphal growth to mostly Blastospores (yeast-like cells). The underlying molecular mechanisms involved in this shift remain elusive. A systematic transcriptome analysis of the differential gene expression was preformed to uncover the fungal transcriptomic response to osmotic and oxidative stresses associated with the resulting high blastospore yield. Differential gene expression was compared under moderate (10% w/v) and high (20% w/v) glucose concentrations daily for three days. The RNAseq-based transcriptomic results depicted a higher proportion of downregulated genes when the fungus was grown under 20% glucose than 10%. Additional experiments explored a broader glucose range (4, 8, 12, 16, 20% w/v) with phenotype assessment and qRT-PCR transcript abundance measurements of selected genes. Antioxidant, calcium transport, conidiation, and osmosensor-related genes were highly upregulated in higher glucose titers (16-20%) compared to growth in lower glucose (4-6%) concentrations. The class 1 hydrophobin gene (Hyd1) was highly expressed throughout the culturing. Hyd1 is known to be involved in spore coat rodlet layer assembly, and indicates that Blastospores or another cell type containing hydrophobin 1 is expressed in the haemocoel during the infection process. Furthermore, we found implications of the HOG signaling pathway with upregulation of homologous genes Ssk2 and Hog1 for all fermentation time points under hyperosmotic medium (20% glucose). These findings expand our knowledge of the molecular mechanisms behind blastospore development and may help facilitate large-scale industrial production of B. bassiana Blastospores for pest control applications.
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Growth kinetic and nitrogen source optimization for liquid culture fermentation of Metarhizium robertsii Blastospores and bioefficacy against the corn leafhopper Dalbulus maidis
World Journal of Microbiology and Biotechnology, 2020Co-Authors: Natasha Sant Anna Iwanicki, Gabriel Moura Mascarin, Sara Giro Moreno, Jørgen Eilenberg, Ítalo Delalibera JúniorAbstract:The cosmopolitan entomopathogenic and root endophytic fungus Metarhizium robertsii has a versatile lifestyle and during liquid fermentation undergoes a dimorphic transformation from hyphae to conidia or microsclerotia, or from hyphae to Blastospores. In all cases, these processes are mediated by environmental and nutritional cues. Blastospores could be used in spray applications to control arthropod pests above ground and may serve as an attractive alternative to the traditional solid-grown aerial conidial spores of Metarhizium spp. found in commercial products. Nitrogen is a vital nutrient in cell metabolism and growth; however, it is the expensive component in liquid cultures of entomopathogenic fungi. Our goals in this study were to optimize nitrogen sources and titers for maximum production of M. robertsii Blastospores cultured in shake flasks at highly aerated conditions and to further determine their virulence against the corn leafhopper Dalbulus maidis , an important vector of serious pathogens in maize crops worldwide. Our fermentation studies revealed that the low-cost corn steep liquor (CSL) was the most suitable nitrogen source to improve blastospore growth in M. robertsii. The growth kinetic assays determined the optimal titer of 80 g L^−1 and a yield up to 4.7 × 10^8 cells mL^−1 within 5 days of cultivation (3 days preculture and 2 days culture), at a total cost of US$0.30 L^−1. Moreover, the blastospore growth kinetic was strongly dependent on glucose and nitrogen consumptions accompanied by a slight drop in the culture pH. Insect bioassays evidenced a high virulence of these Blastospores, either as dried or fresh cells, to D. maidis adults fed on maize plants. Our findings provide insights into the nutritional requirements for optimal and cost-efficient production of M. robertsii Blastospores and elucidate the potential of Blastospores as an ecofriendly tool against the corn leafhopper.
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comparative virulence of Blastospores and conidia of beauveria bassiana and cordyceps fumosorosea against soybean pests
2019Co-Authors: B Correa, Gabriel Moura Mascarin, Vanessa Da Silveira Duarte, D M Silva, Italo DelaliberaAbstract:Entomopathogenic fungi are biocontrol agents capable to infect many insect pests and can produce different infection propagules in artificial media. The soybean crop suffers with attack of many pests and an ideal option would be the use of a single fungal species for the control of a broad host range of this crop. This study aimed to compare the virulence of conidia and Blastospores (fresh or air dried) of Beauveria bassiana (Bals.) Vuill. and Cordyceps fumosorosea (Wize) Kepler (Cordycipitaceae) against Bemisia tabaci (Gennadius) biotype B (Aleyrodidae), Chrysodeixis includens (Walker) and Spodoptera frugiperda (JE Smith) (Noctuidae). Two isolates of each fungal species were selected and their conidia and Blastospores were obtained by solid and liquid fermentation process, respectively. Blastospores were dried using an air drying method. Bioassays were performed with 2nd and 3rd instar nymphs of B. tabaci and 3rd instar larvae of C. includens and S. frugiperda. Suspensions of Blastospores and conidia in a concentration of 5 × 107 propagules mL-1 were sprayed on the insects, and the control received only distilled water + Tween (0.02%). The mortality was recorded during 10 days. For B. tabaci, the air dried Blastospores of ESALQ1296 (C. fumosorosea) and ESALQ543 (B. bassiana) caused the highest mortalities (83.97% and 66.47%, respectively) and exhibited the smallest median survival times (ST50 = 4 and 6 days, respectively). S. frugiperda larvae treated with air dried Blastospores of ESALQ3422 and ESALQ1296 (C. fumosorosea) presented the highest mortalities (87.50% and 91.25%, respectively) with ST50 of 4 and 3 days. For C. includens, fresh Blastospores of ESALQ1296 was the most lethal propagule, killing 79.17% of larvae and attaining ST50 of 4 days. Thus, Blastospores of the two fungal species hold great promise as active propagule for the control of these important soybean pests. Entomopathogenic fungi are biocontrol agents capable to infect many insect pests and can produce different infection propagules in artificial media. The soybean crop suffers with attack of many pests and an ideal option would be the use of a single fungal species for the control of a broad host range of this crop. This study aimed to compare the virulence of conidia and Blastospores (fresh or air dried) of Beauveria bassiana (Bals.) Vuill. and Cordyceps fumosorosea (Wize) Kepler (Cordycipitaceae) against Bemisia tabaci (Gennadius) biotype B (Aleyrodidae), Chrysodeixis includens (Walker) and Spodoptera frugiperda (JE Smith) (Noctuidae). Two isolates of each fungal species were selected and their conidia and Blastospores were obtained by solid and liquid fermentation process, respectively. Blastospores were dried using an air drying method. Bioassays were performed with 2nd and 3rd instar nymphs of B. tabaci and 3rd instar larvae of C. includens and S. frugiperda. Suspensions of Blastospores and conidia in a concentration of 5 × 107 propagules mL-1 were sprayed on the insects, and the control received only distilled water + Tween (0.02%). The mortality was recorded during 10 days. For B. tabaci, the air dried Blastospores of ESALQ1296 (C. fumosorosea) and ESALQ543 (B. bassiana) caused the highest mortalities (83.97% and 66.47%, respectively) and exhibited the smallest median survival times (ST50 = 4 and 6 days, respectively). S. frugiperda larvae treated with air dried Blastospores of ESALQ3422 and ESALQ1296 (C. fumosorosea) presented the highest mortalities (87.50% and 91.25%, respectively) with ST50 of 4 and 3 days. For C. includens, fresh Blastospores of ESALQ1296 was the most lethal propagule, killing 79.17% of larvae and attaining ST50 of 4 days. Thus, Blastospores of the two fungal species hold great promise as active propagule for the control of these important soybean pests.
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Modified Adamek's medium renders high yields of Metarhizium robertsii Blastospores that are desiccation tolerant and infective to cattle-tick larvae.
Fungal biology, 2018Co-Authors: Natasha Sant Anna Iwanicki, Gabriel Moura Mascarin, Bruna De Oliveira Ferreira, Italo Delalibera JúniorAbstract:Abstract Blastospores are yeast-like cells produced by entomopathogenic fungi that are infective to arthropods. The economical feasible production of Blastospores of the insect killing fungus Metarhizium spp. must be optimized to increase yields. Moreover, stabilization process is imperative for blastospore formulation as a final product. In this sense, our goal was to increase blastospore production of two Metarhizium isolates (ESALQ1426 and ESALQ4676) in submerged liquid cultures. A modified Adamek's medium was supplemented with increased glucose concentrations and the fermentation time was accelerated by using a blastospore pre-culture as inoculum. Virulence of air-dried stable Blastospores was compared with conidia toward larvae of the cattle tick, Rhipicephalus microplus. Our results revealed that blastospore production of Metarhizium is isolate- and species-dependent. Glucose-enriched cultures (140 g glucose/L) inoculated with pre-cultures improved yields with optimal growth conditions attained for Metarhizium robertsii ESALQ1426 that rendered as high as 5.9 × 108 Blastospores/mL within 2 d. Resultant air-dried Blastospores of ESALQ1426 were firstly proved to infect and quickly kill cattle tick larvae with comparable efficiency to conidia. Altogether, we argue that both osmotic pressure, induced by high glucose titers, and isolate selection are critical to produce high yields of Blastospores that hold promise to control cattle-tick larvae.
Italo Delalibera - One of the best experts on this subject based on the ideXlab platform.
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development of novel spray dried and air dried formulations of metarhizium robertsii Blastospores and their virulence against dalbulus maidis
Applied Microbiology and Biotechnology, 2021Co-Authors: Natasha Sant Anna Iwanicki, Gabriel Moura Mascarin, Sara Giro Moreno, Jørgen Eilenberg, Italo DelaliberaAbstract:The present research addressed spray-drying and air-drying techniques applied to Metarhizium robertsii Blastospores to develop wettable powder (WP) formulations. We investigated the effect of co-formulants on blastospore viability during drying and assessed the wettability and stability of formulations in water. The effect of oxygen-moisture absorbers was studied on the shelf life of these formulations stored at 26 °C and 4 °C for up to 90 days. Additionally, we determined the virulence of the best spray-dried and air-dried formulations against the corn leafhopper Dalbulus maidis. While sucrose and skim milk played an essential role as osmoprotectants in preserving air-dried Blastospores, maltodextrin, skim milk, and bentonite were crucial to attain high cell survival during spray drying. The lowest wettability time was achieved with spray-dried formulations containing less Ca-lignin, while charcoal powder amount was positively associated with formulation stability. The addition of oxygen-moisture absorbers inside sealed packages increased from threefold to fourfold the half-life times of air-dried and spray-dried formulations at both storage temperatures. However, the half-life times of all blastospore-based formulations were shorter than 3 months regardless of temperature and packaging system. Spray-dried and air-dried WP formulations were as virulent as fresh blastopores against D. maydis adults sprayed with 5 × 107 Blastospores mL−1 that induced 87.8% and 70.6% mortality, respectively. These findings bring innovative advancement for M. robertsii blastospore formulation through spray-drying and underpin the importance of adding protective matrices coupled to oxygen-moisture absorbers to extend cell viability during either cold or non-refrigerated storage. • Cost-effective wettable powder formulations of M. robertsii Blastospores were developed. • Bioefficacy of formulations against the corn leafhopper was comparable to fresh Blastospores. • Cold storage and dual oxygen-moisture absorber are critical for extended shelf life.
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transcriptional responses of beauveria bassiana Blastospores cultured under varying glucose concentrations
Frontiers in Cellular and Infection Microbiology, 2021Co-Authors: Gabriel Moura Mascarin, Italo Delalibera, Natasha Sant Anna Iwanicki, Jose Luis Ramirez, Christopher A DunlapAbstract:Culturing the entomopathogenic fungus, Beauveria bassiana, under high glucose concentrations coupled with high aeration results in a fungal developmental shift from hyphal growth to mostly Blastospores (yeast-like cells). The underlying molecular mechanisms involved in this shift remain elusive. A systematic transcriptome analysis of the differential gene expression was preformed to uncover the fungal transcriptomic response to osmotic and oxidative stresses associated with the resulting high blastospore yield. Differential gene expression was compared under moderate (10% w/v) and high (20% w/v) glucose concentrations daily for three days. The RNAseq-based transcriptomic results depicted a higher proportion of downregulated genes when the fungus was grown under 20% glucose than 10%. Additional experiments explored a broader glucose range (4, 8, 12, 16, 20% w/v) with phenotype assessment and qRT-PCR transcript abundance measurements of selected genes. Antioxidant, calcium transport, conidiation, and osmosensor-related genes were highly upregulated in higher glucose titers (16-20%) compared to growth in lower glucose (4-6%) concentrations. The class 1 hydrophobin gene (Hyd1) was highly expressed throughout the culturing. Hyd1 is known to be involved in spore coat rodlet layer assembly, and indicates that Blastospores or another cell type containing hydrophobin 1 is expressed in the haemocoel during the infection process. Furthermore, we found implications of the HOG signaling pathway with upregulation of homologous genes Ssk2 and Hog1 for all fermentation time points under hyperosmotic medium (20% glucose). These findings expand our knowledge of the molecular mechanisms behind blastospore development and may help facilitate large-scale industrial production of B. bassiana Blastospores for pest control applications.
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comparative virulence of Blastospores and conidia of beauveria bassiana and cordyceps fumosorosea against soybean pests
2019Co-Authors: B Correa, Gabriel Moura Mascarin, Vanessa Da Silveira Duarte, D M Silva, Italo DelaliberaAbstract:Entomopathogenic fungi are biocontrol agents capable to infect many insect pests and can produce different infection propagules in artificial media. The soybean crop suffers with attack of many pests and an ideal option would be the use of a single fungal species for the control of a broad host range of this crop. This study aimed to compare the virulence of conidia and Blastospores (fresh or air dried) of Beauveria bassiana (Bals.) Vuill. and Cordyceps fumosorosea (Wize) Kepler (Cordycipitaceae) against Bemisia tabaci (Gennadius) biotype B (Aleyrodidae), Chrysodeixis includens (Walker) and Spodoptera frugiperda (JE Smith) (Noctuidae). Two isolates of each fungal species were selected and their conidia and Blastospores were obtained by solid and liquid fermentation process, respectively. Blastospores were dried using an air drying method. Bioassays were performed with 2nd and 3rd instar nymphs of B. tabaci and 3rd instar larvae of C. includens and S. frugiperda. Suspensions of Blastospores and conidia in a concentration of 5 × 107 propagules mL-1 were sprayed on the insects, and the control received only distilled water + Tween (0.02%). The mortality was recorded during 10 days. For B. tabaci, the air dried Blastospores of ESALQ1296 (C. fumosorosea) and ESALQ543 (B. bassiana) caused the highest mortalities (83.97% and 66.47%, respectively) and exhibited the smallest median survival times (ST50 = 4 and 6 days, respectively). S. frugiperda larvae treated with air dried Blastospores of ESALQ3422 and ESALQ1296 (C. fumosorosea) presented the highest mortalities (87.50% and 91.25%, respectively) with ST50 of 4 and 3 days. For C. includens, fresh Blastospores of ESALQ1296 was the most lethal propagule, killing 79.17% of larvae and attaining ST50 of 4 days. Thus, Blastospores of the two fungal species hold great promise as active propagule for the control of these important soybean pests. Entomopathogenic fungi are biocontrol agents capable to infect many insect pests and can produce different infection propagules in artificial media. The soybean crop suffers with attack of many pests and an ideal option would be the use of a single fungal species for the control of a broad host range of this crop. This study aimed to compare the virulence of conidia and Blastospores (fresh or air dried) of Beauveria bassiana (Bals.) Vuill. and Cordyceps fumosorosea (Wize) Kepler (Cordycipitaceae) against Bemisia tabaci (Gennadius) biotype B (Aleyrodidae), Chrysodeixis includens (Walker) and Spodoptera frugiperda (JE Smith) (Noctuidae). Two isolates of each fungal species were selected and their conidia and Blastospores were obtained by solid and liquid fermentation process, respectively. Blastospores were dried using an air drying method. Bioassays were performed with 2nd and 3rd instar nymphs of B. tabaci and 3rd instar larvae of C. includens and S. frugiperda. Suspensions of Blastospores and conidia in a concentration of 5 × 107 propagules mL-1 were sprayed on the insects, and the control received only distilled water + Tween (0.02%). The mortality was recorded during 10 days. For B. tabaci, the air dried Blastospores of ESALQ1296 (C. fumosorosea) and ESALQ543 (B. bassiana) caused the highest mortalities (83.97% and 66.47%, respectively) and exhibited the smallest median survival times (ST50 = 4 and 6 days, respectively). S. frugiperda larvae treated with air dried Blastospores of ESALQ3422 and ESALQ1296 (C. fumosorosea) presented the highest mortalities (87.50% and 91.25%, respectively) with ST50 of 4 and 3 days. For C. includens, fresh Blastospores of ESALQ1296 was the most lethal propagule, killing 79.17% of larvae and attaining ST50 of 4 days. Thus, Blastospores of the two fungal species hold great promise as active propagule for the control of these important soybean pests.
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Nitrogen sources affect productivity, desiccation tolerance and storage stability of Beauveria bassiana Blastospores
Journal of applied microbiology, 2018Co-Authors: Gabriel Moura Mascarin, Mark A Jackson, Nilce Naomi Kobori, Christopher A Dunlap, Italo DelaliberaAbstract:AIMS Nitrogen is a critical element in industrial fermentation media. This study investigated the influence of various nitrogen sources on blastospore production, desiccation tolerance and storage stability using two strains of the cosmopolitan insect-pathogenic fungus Beauveria bassiana. METHODS AND RESULTS Complex organic sources of nitrogen such as soy flour, autolysed yeast and cottonseed flour induced great numbers of Blastospores after 2-3 days of fermentation, which also survived drying and remained viable (32-56% survival) after 9 months storage at 4°C, although variations were found between strains. Nitrogen availability in the form of free amino acids directly influenced blastospore production and resistance to desiccation. Increasing glucose and nitrogen concentrations up to 120 and 30 g l-1 , respectively, did not improve blastospore production but enhanced desiccation tolerance. Cell viability after drying and upon fast-rehydration was increased when ≥25 g acid-hydrolysed casein per litre was supplemented in the liquid culture medium. CONCLUSIONS These findings indicate that low-cost complex nitrogen compounds are suitable to enhance yeast-like growth by B. bassiana with good desiccation tolerance and therefore support its further scale-up production as a mycoinsecticide. SIGNIFICANCE AND IMPACT OF THE STUDY Nitrogen is the most expensive nutrient in liquid media composition, but this study underscores the feasibility of using low-cost nitrogen compounds composed mainly of agro-industrial by-products for rapid production of desiccation-tolerant B. bassiana Blastospores by liquid culture fermentation.
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improved shelf life of dried beauveria bassiana Blastospores using convective drying and active packaging processes
Applied Microbiology and Biotechnology, 2016Co-Authors: Robert W Behle, Mark A Jackson, Nilce Naomi Kobori, Gabriel Moura Mascarin, Italo DelaliberaAbstract:The yeast form (blastospore) of the dimorphic insect-pathogenic fungus Beauveria bassiana can be rapidly produced using liquid fermentation methods but is generally unable to survive rapid dehydration processes or storage under non-refrigerated conditions. In this study, we evaluated the influence of two convective drying methods, various modified atmosphere packaging systems, and storage temperatures on the desiccation tolerance, storage stability, and virulence of Blastospores of B. bassiana ESALQ 1432. All blastospore formulations were dried to <5 % water content equivalent to aw < 0.3. The viability of B. bassiana Blastospores after air drying and spray drying was greater than 80 %. Vacuum-packaged Blastospores remained viable longer when stored at 4 °C compared with 28 °C with virtually no loss in viability over 9 months regardless the drying method. When both oxygen and moisture scavengers were added to sealed packages of dried blastospore formulations stored at 28 °C, viability was significantly prolonged for both air- and spray-dried Blastospores. The addition of ascorbic acid during spray drying did not improve desiccation tolerance but enhanced cell stability (∼twofold higher half-life) when stored at 28 °C. After storage for 4 months at 28 °C, air-dried Blastospores produced a lower LC80 and resulted in higher mortality to whitefly nymphs (Bemisia tabaci) when compared with spray-dried Blastospores. These studies identified key storage conditions (low aw and oxygen availability) that improved blastospore storage stability at 28 °C and will facilitate the commercial development of Blastospores-based bioinsecticides.
Tariq M. Butt - One of the best experts on this subject based on the ideXlab platform.
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metarhizium anisopliae Blastospores are highly virulent to adult aedes aegypti an important arbovirus vector
Parasites & Vectors, 2021Co-Authors: Adriano Rodrigues De Paula, Tariq M. Butt, Leila Eid Imad Da Silva, Anderson Ribeiro, Gerson Adriano Silva, Carlos P Silva, Richard SamuelsAbstract:Background The use of entomopathogenic fungi (EPF) for the control of adult mosquitoes is a promising alternative to synthetic insecticides. Previous studies have only evaluated conidiospores against adult mosquitoes. However, Blastospores, which are highly virulent against mosquito larvae and pupae, could also be effective against adults. Methods Metarhizium anisopliae (ESALQ 818 and LEF 2000) Blastospores and conidia were first tested against adult Aedes aegypti by spraying insects with spore suspensions. Blastospores were then tested using an indirect contact bioassay, exposing mosquitoes to fungus-impregnated cloths. Virulence when using Blastospores suspended in 20% sunflower oil was also investigated. Results Female mosquitoes sprayed with Blastospores or conidia at a concentration of 108 propagules ml-1 were highly susceptible to both types of spores, resulting in 100% mortality within 7 days. However, significant differences in virulence of the isolates and propagules became apparent at 107 spores ml-1, with ESALQ 818 Blastospores being more virulent than LEF 2000 Blastospores. ESALQ 818 Blastospores were highly virulent when mosquitoes were exposed to black cotton cloths impregnated with Blastospores shortly after preparing the suspensions, but virulence declined rapidly 12 h post-application. The addition of vegetable oil to Blastospores helped maintain virulence for up to 48 h. Conclusion The results showed that Blastospores were more virulent to adult female Ae. aegypti than conidia when sprayed onto the insects or applied to black cloths. Vegetable oil helped maintain blastospore virulence. The results show that Blastospores have potential for use in integrated vector management, although new formulations and drying techniques need to be investigated.
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combined use of the entomopathogenic fungus metarhizium brunneum and the mosquito predator toxorhynchites brevipalpis for control of mosquito larvae is this a risky biocontrol strategy
Journal of Invertebrate Pathology, 2018Co-Authors: Abeer M. Alkhaibari, Thierry Maffeis, James C. Bull, Tariq M. ButtAbstract:Abstract Mosquitoes transmit several diseases, which are of global significance (malaria, dengue, yellow fever, Zika). The geographic range of mosquitoes is increasing due to climate change, tourism and trade. Both conidial and blastospore formulations of the entomopathogenic fungus, Metarhizium brunneum ARSEF 4556, are being investigated as mosquito larvicides. However, concerns have been raised over possible non-target impacts to arthropod mosquito predators such as larvae of Toxorhynchites brevipalpis which feed on larvae of mosquito vector species. Laboratory-based, small container bioassays showed, that T. bevipalpis larvae are susceptible to relatively high concentrations (i.e. ≥107 spores ml−1) of inoculum with Blastospores being significantly more virulent than conidia. At lower concentrations (e.g.
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Highly specific host-pathogen interactions influence Metarhizium brunneum blastospore virulence against Culex quinquefasciatus larvae
2018Co-Authors: Abeer M. Alkhaibari, Thierry Maffeis, James C. Bull, Richard I. Samuels, Alex M. Lord, Fabio L. Olivares, Tariq M. ButtAbstract:Entomopathogenic fungi are potential biological control agents of mosquitoes. Our group observed that not all mosquitoes were equally susceptible to fungal infection and observed significant differences in virulence of different spore types. Conidiospores and Blastospores were tested against Culex quinquefasciatus larvae. Blastospores are normally considered more virulent than conidia as they form germ tubes and penetrate the host integument more rapidly than conidia. However, when tested against Cx. quinquefasciatus, Blastospores were less virulent than conidia. This host-fungus interaction was studied by optical, electron and atomic force microscopy (AFM). Furthermore, host immune responses and specific gene expression were investigated. Metarhizium brunneum (formerly M. anisopliae) ARSEF 4556 Blastospores did not readily adhere to Culex larval integument and the main route of infection was through the gut. Adhesion forces between Blastospores and Culex cuticle were significantly lower than for other insects. Larvae challenged with Blastospores showed enhanced immune responses, with increased levels of phenoloxidase, glutathione-S-transferase, esterase, superoxide dismutase and lipid peroxidase activity. Interestingly, M. brunneum pathogenicity/stress-related genes were all down-regulated in Blastospores exposed to Culex. Conversely, when conidia were exposed to Culex, the pathogenicity genes involved in adhesion or cuticle degradation were up-regulated. Delayed host mortality following blastospore infection of Culex was probably due to lower adhesion rates of Blastospores to the cuticle and enhanced host immune responses deployed to counter infection. The results here show that subtle differences in host-pathogen interactions can be responsible for significant changes in virulence when comparing mosquito species, having important consequences for biological control strategies and the understanding of pathogenicity processes.
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Metarhizium brunneum Blastospore Pathogenesis in Aedes aegypti Larvae: Attack on Several Fronts Accelerates Mortality
PLoS pathogens, 2016Co-Authors: Abeer M. Alkhaibari, Aline T. Carolino, Sare I. Yavasoglu, Thierry Maffeis, James C. Bull, Thalles Cardoso Mattoso, Richard Ian Samuels, Tariq M. ButtAbstract:Aedes aegypti is the vector of a wide range of diseases (e.g. yellow fever, dengue, Chikungunya and Zika) which impact on over half the world’s population. Entomopathogenic fungi such as Metarhizium anisopliae and Beauveria bassiana have been found to be highly efficacious in killing mosquito larvae but only now are the underlying mechanisms for pathogenesis being elucidated. Recently it was shown that conidia of M. anisopliae caused stress induced mortality in Ae. aegypti larvae, a different mode of pathogenicity to that normally seen in terrestrial hosts. Blastospores constitute a different form of inoculum produced by this fungus when cultured in liquid media and although Blastospores are generally considered to be more virulent than conidia no evidence has been presented to explain why. In our study, using a range of biochemical, molecular and microscopy methods, the infection process of Metarhizium brunneum (formerly M. anisopliae) ARSEF 4556 Blastospores was investigated. It appears that the Blastospores, unlike conidia, readily adhere to and penetrate mosquito larval cuticle. The Blastospores are readily ingested by the larvae but unlike the conidia are able infect the insect through the gut and rapidly invade the haemocoel. The fact that pathogenicity related genes were upregulated in Blastospores exposed to larvae prior to invasion, suggests the fungus was detecting host derived cues. Similarly, immune and defence genes were upregulated in the host prior to infection suggesting mosquitoes were also able to detect pathogen-derived cues. The hydrophilic Blastospores produce copious mucilage, which probably facilitates adhesion to the host but do not appear to depend on production of Pr1, a cuticle degrading subtilisin protease, for penetration since protease inhibitors did not significantly alter blastospore virulence. The fact the Blastospores have multiple routes of entry (cuticle and gut) may explain why this form of the inoculum killed Ae. aegypti larvae in a relatively short time (12-24hrs), significantly quicker than when larvae were exposed to conidia. This study shows that selecting the appropriate form of inoculum is important for efficacious control of disease vectors such as Ae. aegypti.
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Transmission electron microscopy of Aedes aegypti larvae infected with Metarhizium brunneum Blastospores 24 hr post-inoculation.
2016Co-Authors: Abeer M. Alkhaibari, Aline T. Carolino, Sare I. Yavasoglu, Thierry Maffeis, Thalles C. Mattoso, James C. Bull, Richard I. Samuels, Tariq M. ButtAbstract:(A) Blastospore (BS) firmly adhering to surface of the cuticle (CU). The blastospore has dense cytoplasm, a relatively thin wall and a coating of mucilage (MU) which extends beyond the fungus. The mucilage consists of heterogeneous electron opaque material. (B) Penetration of the larval cuticle. Vacuoles (V) containing electron dense material evident in the penetration hyphae. Cuticle readily distorted by penetration hypha. (C) Blastospores in gut lumen penetrating the peritrophic membrane (PM). (D) One blastospore has penetrated the midgut epithelium and has entered the haemocoel (H).