Effect of VvLaeA on the growth and development of Beauveria bassiana / 生物工程学报

It is unclear how VvLaeA functions in regulating the growth and development of Volvariella volvacea (Bull. ex. Fr.) Sing.. Firstly, bioinformatics analysis of VvLaeA was carried out in this study. Subsequently, the Vvgpd promoter and the open reading frame (ORF) fragment of VvlaeA were amplified and fused by polymerase chain reaction (PCR). The fusion fragment was cloned into the pK2 (bar) plasmid. The recombinant construct pK2(bar)-OEVvlaeA was transfected into Beauveria bassiana by Agrobacterium tumefaciens-mediated transformation. Finally, the growth and development of the transformants were examined. The results showed that VvLaeA shared a low homology with similar proteins in other fungi. Compared with the wild type, the colony diameter of the transformant was significantly increased. However, the pigment deposition, conidial yields and germination rates were significantly decreased. The overexpression strains were more sensitive to stresses than that of the wild type. Further studies showed the conidial cell wall properties of the transformants were altered, and the expressions of genes related to the conidial development were significantly down-regulated. Collectively, VvLaeA increased the growth rate of B. bassiana strains and negatively regulated the pigmentation and conidial development, which shed a light for the functional identification of straw mushroom genes.

Growth Pattern of Beauveria bassiana in Different Eco-friendly Media

Beauveria bassiana belongs to the class Deuteromycetes which is one of the important disease-causing biocontrol agents in insects. B. bassiana, formerly known as Botrytis bassiana (Balsamo), is a widely distributed soil inhabiting fungus. B. bassiana is also known to be best biocontrol agent against larval stage of the silkworm. B. bassiana is categorized as a white muscardine fungus due to the white color of sporulating colonies. It is a type of biopesticide which is based on entomopathogenic fungi which are often considerable scope as plant protection agents against several pathogens and insects including whiteflies, aphids, thrips, grasshoppers, and certain types of beetles. The present study deals with the use of different media such as coconut media, jaggery media, nutrient media, potato dextrose media, Sabouraud dextrose media, and molasses media

Alternative substrates for conidiogenesis of the entomopathogenic fungus Beauveria bassiana (Bals) Vuillemin (Deuteromycotina: Hyphomycetes) / Substratos alternativos para conidiogênese do fungo entomopatogênico Beauveria bassiana (Bals) Vuillemin (Deuteromycotina: Hyphomycetes)

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.

Resumo Beauveria bassiana é um fungo promissor no controle biológico de insetos-praga. As crescentes despesas na produção de conídios levantam a necessidade de averiguar a eficiência de alguns substratos de baixo custo. O objetivo deste trabalho foi analisar o potencial de utilização de diferentes substratos brutos para a conidiogênese de B. bassiana. O crescimento e esporulação foram realizados utilizando 30 g do substrato e 0,3 µL da suspensão de conídios (1 x 106 conídios/mL). Após 10 dias de incubação (umidade 70 ± 10% e temperatura T = 29 ± 1° C), o arroz (2,00 x 106 conídios/g de substrato), algaroba (2,36 x 106 conídios/g), malte A (1,22 x 106 conídios/g) e B (1,75 x 106 conídios/g), apresentaram maior produção de conídios. Os conídios produzidos mostraram atividade inseticida sobre o cupim do coqueiro acima de 80% de mortalidade. Estes novos substratos brutos podem representar uma alternativa viável para produção de fungos entomopatogênicos para uso no controle biológico de vários insetos praga.

Pathogenicity of Metarhizium anisopliae and Beauveria bassiana fungi to Tetranychus ludeni (Acari: Tetranychidae) / Patogenicidade de fungos Metarhizium anisopliae e Beauveria bassiana ao Tetranychus ludeni (Acari: Tetranychidae)

The use of acaricides is the main control method for Tetranychus ludeni (Acari: Tetranychidae) in horticultural crops. This mite has been recorded causing damage to sweet potato (Ipomoea batatas L.). The use of pathogenic fungi is an alternative to chemical control. The objective was to evaluate the pathogenicity of the fungi Metarhizium anisopliae (Meetch) Sorok, and Beauveria bassiana (Bals.) Vuill. to phytophagous mite T. ludeni in sweet potato plants. Conidial suspensions of M. anisopliae and B. bassiana, at concentrations of 106 and 107 con.mL-1 were applied to sweet potato leaves. After 24 hours, five females of T. ludeni newly emerged were released on the leaves. The bioassay was arranged in a completely randomized design with factorial arrangement 2 × 2 (two species of fungi and two concentrations) plus the control (distilled water), with 10 repetitions per treatment. The evaluation consisted of observing of three biological parameters of the mite: mortality, oviposition, and repellency, after 24, 48, 72, and 96 hours of contact with the fungi. The isolates of M. anisopliae cause high mortality rates of T. ludeni in laboratory. Beauveria bassiana has the potential to suppress future generations of mite, reducing its oviposition rate. Repellency behavior was not observed.(AU)

O uso de acaricidas é o principal método de controle de Tetranychus ludeni (Acari: Tetranychidae) em cultivos hortícolas. Esse ácaro foi registrado causando danos em batata-doce (Ipomoea batatas (L.). A utilização de fungos patogênicos é uma alternativa ao controle químico. O objetivo foi avaliar a patogenicidade dos fungos Metarhizium anisopliae (Meetch) Sorok. e Beauveria bassiana (Bals.) Vuill. ao ácaro fitófago T. ludeni em batata-doce. Suspensões conidiais de M. anisopliae e B. bassiana, nas concentrações de 106 e 107 con.mL-1, foram aplicadas sobre folhas de batata-doce. Após 24 horas, cinco fêmeas recém-emergidas foram liberadas sobre as folhas. O bioensaio foi inteiramente randomizado, com arranjo fatorial 2 × 2 (duas espécies de fungos e duas concentrações) e controle (água destilada), com 10 replicações por tratamento. A avaliação consistiu na observação de três parâmetros biológicos do ácaro: mortalidade, oviposição e repelência, após 24, 48, 72 e 96 horas de contato com os fungos. Os isolados de M. anisopliae causam altas taxas de mortalidade de T. ludeni em laboratório. Beauveria bassiana tem potencial para suprimir futuras gerações do ácaro, reduzindo a taxa de oviposição. Comportamento de repelência nos ácaros não foi observado.(AU)

Secondary Metabolites from a Fungus Beauveria felina SX-6-22 Sponge-Associated / 中国药学杂志

OBJECTIVE: To study the secondary metabolites of sponge-associated fungus Beauveria feline SX-6-22. METHODS: The compounds were isolated and purified by silica gel, ODS reversed-phase column, preparative HPLC techniques. And their structures were identified by the physicochemical properties and NMR, MS data analysis. X-ray crystal diffraction was used to confirm the absolute configuration of compound1. RESULTS: Nine secondary metabolites were isolated from the extract of the solid fermentation culture of strain SX-6-22, including four new compounds beauverins A-D (1-4) and five known compounds 1, 9-dimethyl-3, 7-dibenzofurandiol (5), diorcinol(6), cordyol C(7), mixture of violaceol (8) and violaceol Ⅱ(9). Compounds 5, 7, 8 and 9 showed strong antioxidant activity with IC50 (9.62±0.12), (11.11±0.02), and (8.44±0.08) μg•mL-1 by DPPH assay. CONCLUSION: Four new compounds and three antioxidant known compounds are isolated from sponge-associated fungus SX-6-22.

Selectivity of different biological products to the egg parasitoid Telenomus remus (Hymenoptera: Platygastridae)

ABSTRACT The selectivity of five entomopathogens and a chemical insecticide (positive control) to pupae and adults of the egg parasitoid Telenomus remus (Nixon) was evaluated in the laboratory under controlled environmental conditions according to protocols established by the International Organization for Biological Control. Baculovirus anticarsia (Baculovirus AEE®), Bacillus thuringiensis var. kurstaki (Thuricide®), Bacillus thuringiensis var. aizawai (Agree®), Beauveria bassiana (Boveril®), Metarhizium anisopliae (Metarril®) and Trichoderma harzianum (Trichodermil®) are harmless to T. remus pupae, and adults. Thus, our results suggest that the insect control strategies applied here are compatible since entomopathogens were classified as harmless to T. remus in most examined cases and therefore facilitate a joint application to control different pests. Bacillus thuringiensis var. kurstaki (Dipel®), despite being classified as slightly harmful in some of the evaluations, can still be considered compatible for use together with T. remus, especially when compared with chemical insecticides such as chlorpyrifos that might be considered harmful to the parasitoid survival.

Alternative phytosanitary products against to white muscardine in Bombyx mori L. (Lepidoptera: Bombycidae) / Produtos fitossanitários alternativos contra a calcinose em Bombyx mori L. (Lepidoptera: Bombycidae)

This work aimed to evaluate the effects of the products Biogermex®, Agro-mos®, Soil-Set® and Planta Clean® on the development of white muscardine in Bombyx mori. Products have been tested at two stages for effects on biology of caterpillars and on silk production (1), and then they were evaluated to know their potential in the prevention/control of white muscardine (2). Products were sprayed on mulberry leaves (preventive treatment) and also on the integument of silkworms (curative treatment). At the first stage, the products were applied on four consecutive days, in one of the daily feeds. Planta Clean® - curative treatment - and Soil-Set® - preventive treatment - caused mortality in 63.3% and 30% of silk worms, respectively. The fungus Beauveria bassiana was inoculated at the concentration 5 × 107 conidia/mL on the leaves and insects. The products were applied three hours after application on the fungus, in a single application, and also for four days in the other groups. A group of silkworms sprayed only with the fungus served as control. Biogermex® - curative treatment applied once and for four times - was the most effective, reducing mortality by 25 and 26.7%, respectively, as compared with the control group. None of the evaluated products acts preventively against white muscardine.

Este trabalho objetivou avaliar os efeitos de produtos Biogermex®, Agro-mos®, Soil-Set® e Planta Clean® no desenvolvimento da calcinose branca em Bombyx mori. Os produtos foram testados em duas etapas: efeitos sobre a biologia e produção de seda pela lagarta (1) e, em seguida, em função do seu potencial na prevenção/no controle da calcinose branca (2). Os produtos foram pulverizados sobre as folhas de amoreira (tratamento preventivo) e sobre o tegumento das lagartas (tratamento curativo). Na primeira etapa, os produtos foram aplicados durante quatro dias consecutivos, em uma das alimentações do dia. Planta Clean® - tratamento curativo - e Soil-Set® - tratamento preventivo - causaram mortalidade em 63,3 e 30% das lagartas, respectivamente. O fungo Beauveria bassiana foi inoculado na concentração 5 × 107 conídios/mL sobre folhas e insetos. Os produtos foram aplicados três horas após o fungo, em uma aplicação, e também por quatro dias em outro grupo. Um grupo de lagartas pulverizadas apenas com fungo serviu como controle. Biogermex® - tratamento curativo aplicado uma e quatro vezes - foi o mais eficiente, reduzindo a mortalidade em 25 e 26,7% respectivamente, em relação ao grupo controle. Nenhum dos produtos avaliados atuou de forma preventiva contra muscardina branca.

Alternative phytosanitary products against to white muscardine in Bombyx mori L. (Lepidoptera: Bombycidae) / Produtos fitossanitários alternativos contra a calcinose em Bombyx mori L. (Lepidoptera: Bombycidae)

This work aimed to evaluate the effects of the products Biogermex®, Agro-mos®, Soil-Set® and Planta Clean® on the development of white muscardine in Bombyx mori. Products have been tested at two stages for effects on biology of caterpillars and on silk production (1), and then they were evaluated to know their potential in the prevention/control of white muscardine (2). Products were sprayed on mulberry leaves (preventive treatment) and also on the integument of silkworms (curative treatment). At the first stage, the products were applied on four consecutive days, in one of the daily feeds. Planta Clean® - curative treatment - and Soil-Set® - preventive treatment - caused mortality in 63.3% and 30% of silk worms, respectively. The fungus Beauveria bassiana was inoculated at the concentration 5 × 107 conidia/mL on the leaves and insects. The products were applied three hours after application on the fungus, in a single application, and also for four days in the other groups. A group of silkworms sprayed only with the fungus served as control. Biogermex® - curative treatment applied once and for four times - was the most effective, reducing mortality by 25 and 26.7%, respectively, as compared with the control group. None of the evaluated products acts preventively against white muscardine.(AU)

Este trabalho objetivou avaliar os efeitos de produtos Biogermex®, Agro-mos®, Soil-Set® e Planta Clean® no desenvolvimento da calcinose branca em Bombyx mori. Os produtos foram testados em duas etapas: efeitos sobre a biologia e produção de seda pela lagarta (1) e, em seguida, em função do seu potencial na prevenção/no controle da calcinose branca (2). Os produtos foram pulverizados sobre as folhas de amoreira (tratamento preventivo) e sobre o tegumento das lagartas (tratamento curativo). Na primeira etapa, os produtos foram aplicados durante quatro dias consecutivos, em uma das alimentações do dia. Planta Clean® - tratamento curativo - e Soil-Set® - tratamento preventivo - causaram mortalidade em 63,3 e 30% das lagartas, respectivamente. O fungo Beauveria bassiana foi inoculado na concentração 5 × 107 conídios/mL sobre folhas e insetos. Os produtos foram aplicados três horas após o fungo, em uma aplicação, e também por quatro dias em outro grupo. Um grupo de lagartas pulverizadas apenas com fungo serviu como controle. Biogermex® - tratamento curativo aplicado uma e quatro vezes - foi o mais eficiente, reduzindo a mortalidade em 25 e 26,7% respectivamente, em relação ao grupo controle. Nenhum dos produtos avaliados atuou de forma preventiva contra muscardina branca.(AU)

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

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 L 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.

Resumo Beauveria bassiana é um fungo promissor no controle biológico de insetos-praga. As crescentes despesas na produção de conídios levantam a necessidade de averiguar a eficiência de alguns substratos de baixo custo. O objetivo deste trabalho foi analisar o potencial de utilização de diferentes substratos brutos para a conidiogênese de B. bassiana. O crescimento e esporulação foram realizados utilizando 30 g do substrato e 0,3 µL da suspensão de conídios (1 x 106 conídios/mL). Após 10 dias de incubação (umidade 70 ± 10% e temperatura T = 29 ± 1° C), o arroz (2,00 x 106 conídios/g de substrato), algaroba (2,36 x 106 conídios/g), malte A (1,22 x 106 conídios/g) e B (1,75 x 106 conídios/g), apresentaram maior produção de conídios. Os conídios produzidos mostraram atividade inseticida sobre o cupim do coqueiro acima de 80% de mortalidade. Estes novos substratos brutos podem representar uma alternativa viável para produção de fungos entomopatogênicos para uso no controle biológico de vários insetos praga.

Virulence evaluation of entomopathogenic fungi to subterranean termites, Globitermes sulphureus (INSECTA: ISOPTERA)

Aims: Subterranean termites, Globitermes sulphureus is one of the significant pests for agricultural crops such as coconut and oil palm, and occasionally attacks building structure in Malaysia. Efforts to control subterranean termite infestations depended heavily on liquid termiticide applications. Natural pathogen of termites such as entomopathogenic fungi (EPF) is a promising alternative to chemical control. The objective of this study was to determine the most virulent EPF such as Metarhizium anisopliae, Beauveria bassiana and Paecilomyces sp. against the subterranean termites, G. sulphureus for the development of bio-insecticide for future use of termite control. Methodology and results: Subterranean termites were collected from mound-building termites found in Universiti Malaysia Terengganu (UMT). Cultivating, harvesting and counting of conidia of EPF were carried out to prepare the desired concentrations for screening test and bioassays, which were 1×103 , 1x105 , 1×107 and control. The pathogenicity testing was observed daily within 1 week under laboratory conditions. Screening showed that M. anisopliae was found to be the most virulent compared to B. bassiana and Paecilomyces sp., achieving 100% mortality within 3-4 days. M. anisopliae was then further tested on termites and it was found that concentration of 1×107 showed the lowest LT50 value, while LC50 of M. anisopliae in 1 day was 2.0151×106 . Conclusion, significance and impact of study: It could be concluded that M. anisopliae is the most virulent EPF against termites and the most effective concentration was ±107 followed by strains of B. bassiana and Paecilomyces sp. However, there is limited field evaluation of EPF against termites in Malaysia. Evaluation on the efficiency of M. anisopliae in the field should be conducted so that its efficacy could be proven and marketed.

Sensibilidade de isolados de fungos entomopatogênicos às radiações solar, ultravioleta e à temperatura / Sensibility of isolates of entomopathogenic fungi to solar radiation, ultraviolet rays and temperature

Este trabalho teve por objetivo avaliar a sensibilidade de isolados dos fungos Metarhizium anisopliae (Metsch.) Sorok. e Beauveria bassiana (Bals). Vuill. ao efeito das radiações solar e ultravioleta e da temperatura. Conídios dos isolados foram expostos, por vários períodos, aos raios de um simulador solar em diversas irradiâncias e a uma lâmpada de raios ultravioleta germicida. Os conídios do isolado de M. anisopliae foram também expostos às temperaturas de 19,5; 24,2 e 31,0ºC, e os do isolado de B. bassiana a 19,4; 20,8 e 28,3ºC, e 18,7; 23,8 e 30,9ºC. Avaliou-se a germinação de conídios pelo teste de viabilidade. Os isolados dos fungos se mostraram bastantes sensíveis aos raios do simulador solar e aos raios ultravioleta. A germinação de ambos sofreu significativa redução a partir de 30 minutos de exposição à radiação do simulador solar. O efeito mais severo foi evidenciado pelo isolado de B. bassiana, com grande redução da germinação dos conídios em todas as irradiâncias testadas. A sensibilidade à radiação ultravioleta também foi grande, pois ocorreu acentuada redução da germinação dos conídios do isolado de M. anisopliae (38,2%) e de B. bassiana (65%) já aos 30 segundos de exposição. A temperatura afetou a viabilidade de ambos os fungos. Temperaturas entre 23,8 e 31ºC favoreceram a germinação dos conídios, enquanto temperaturas próximas de 20ºC dificultaram a germinação.(AU)

This study aimed to access the sensibility of isolates of the fungus Metarhizium anisopliae (Metsch.) Sorok. and Beauveria bassiana (Bals.) Vuill. to the effect of solar and ultraviolet radiation and temperature. Conidia were exposed for various periods to the rays from a solar simulator at various irradiances, and to light germicidal ultraviolet rays. Conidia of the isolate of M. anisopliae were also exposed to temperatures of 19.5, 24.2 and 31.0ºC and the isolate of B. bassiana to 19.4, 20.8 and 28.3ºC, and also to 18.7, 23.8 and 30.9ºC. The germination of conidia was evaluated by the viability test. The fungal isolates showed to be very sensitive to the solar simulator and ultraviolet rays. Germination of both was significantly decreased starting from 30 minutes of exposure to the rays of the solar simulator. The most severe effect was evidenced by the isolate of B. bassiana with great reduction in conidia germination in all the tested irradiances. Sensitivity to ultraviolet radiation was also great, showing a marked reduction in the germination of M. anisopliae (38.2%) and B. bassiana (65%) conidia after 30 seconds of exposure. The temperature affected the viability of both fungi. Temperatures ranging of 23.8 to 31ºC favor the germination of conidia while temperatures around 20ºC constrained germination.(AU)

Controle e prevenção da calcinose branca em Bombyx mori L. (Lepidoptera: Bombycidae) / Control and prevention of white muscardine in Bombyx mori L. (Lepidoptera: Bombycidae)

Um dos principais problemas enfrentados pelos sericicultores em todo o mundo são entomopatógenos que causam grandes perdas na produção. Destaca-se a doença calcinose branca, causada pelo fungo Beauveria bassiana (Bals.) Vuill. (Ascomycota: Cordycipitaceae). Doenças fúngicas são facilmente disseminadas, já que os conídios são transportados pelo ar. Além disso, as condições de temperatura e umidade nos barracões são favoráveis ao surgimento e à manutenção do fungo, aumentando sua incidência. Práticas de higiene como a desinfecção do barracão e de utensílios são recomendadas, no entanto a contaminação das lagartas ainda é frequente. Dessa forma, esse artigo reuniu trabalhos voltados para a pesquisa de produtos antimicrobianos alternativos para o uso em sericicultura.(AU)

Entomopathogens are the most important problem from sericulture all over the world, and cause heavy loss to silkworm crops. Calcinosis is a common disease of silkworm, caused by the pathogenic fungus Beauveria bassiana (Bals.) Vuill. (Ascomycota: Cordycipitaceae). Fungal diseases of silkworm are easily spread by spores which are carried through the air. Also, temperature and humidity inside the silkworm rearing rooms are favorable to disease development. Practice hygiene measures during silkworm rearing such as disinfection of rearing houses and appliances are recommended. However, contamination is frequent. This paper presents related research on promising antimicrobiotic products for their use in sericulture industry.(AU)

Biological Parameters of Euschistus heros (F.) (Heteroptera: Pentatomidae) and its Susceptibility to Entomopathogenic Fungi When Fed on Different Diets

ABSTRACT: The effects of six diets on biological parameters of Euschistus heros (F.) (Heteroptera: Pentatomidae) and its susceptibility to entomopathogenic fungi Beauveria bassiana (Bb) and Metarhizium anisopliae (Ma) were studied. The diets included a standard diet (bean pods+soybeans, peanuts and sunflower) and diets in which the bean pods were combined with only one type of grain, either soybean, peanut, sunflower, pea or sesame seeds. The best performance was that of insects fed on standard diet, which had the shortest development period and 49.5% of egg-to-adult viability. The insects fed the pea diet exhibited less than 30% viability and 11% of adults had wing deformations. The finite rate of increase values for the treatment groups were: standard: 1.091; soybean: 1.077; peanut: 1.071; sunflower: 1.076; pea: 1.058; and sesame: 1.065. The susceptibility to Ma (55%) was greater than Bb (40%) only for insects fed on the sesame diet. Considering the effects of diet on susceptibility to both fungal species comparatively among the diet-treatment groups, the stink bugs fed the restrictive diets were more susceptible compared with those fed the standard diet. We concluded that diet composition affects the biological parameters of E. heros and differentially affects their susceptibility to Bb and Ma fungi.

Antimicrobial activity of Stomoxys calcitransagainst Beauveria bassiana sensu lato isolates / Atividade antimicrobiana de Stomoxys calcitranscontra isolados de Beauveria bassiana sensu lato

This study had the aims of evaluating the antimicrobial characteristics of Stomoxys calcitrans (Diptera: Muscidae) larvae against the fungal isolates CG138, CG228 and ESALQ986 of Beauveria bassiana sensu lato (Balsamo-Crivelli) Vuillemin, 1912 (Hypocreales: Cordycipitaceae). S. calcitrans eggs, larvae and pupae were exposed to these same isolates. Statistical analysis showed that the immature stages of S. calcitrans were not susceptible to the fungal isolates used, regardless of the exposure method. Diffusion test on solid culture medium reveled that macerated S. calcitrans larvae exposed to isolate CG138 reduced CG138 fungal development. The analysis of the chromatographic profiles indicated that the macerate or mucus of larvae of the control group and the groups exposed to the isolate CG138 presented different profiles. Reduced development of the isolate CG138 on the larvae cuticle was observed by means of scanning electron microscopy.

Este estudo teve como objetivos avaliar as características antimicrobianas de larvas de Stomoxys calcitrans (Diptera: Muscidae) contra os isolados CG138, CG228 e ESALQ986 de Beauveria bassiana sensu lato (Balsamo-Crivelli) Vuillemin, 1912 (Hypocreales: Cordycipitaceae). Ovos, larvas e pupas de S. calcitrans foram expostos a estes mesmos isolados. Após análise estatística, foi verificado que os estágios imaturos de S. calcitrans não foram susceptíveis aos isolados utilizados, independentemente do método de exposição utilizado. O teste de difusão em meio sólido mostrou que quando o isolado CG138 foi exposto a macerado de larvas houve redução do desenvolvimento fúngico. A análise dos perfis cromatográficos mostrou que o macerado ou muco de larvas do grupo controle e dos grupos expostos ao isolado CG138 apresentaram diferenças nos perfis. Um desenvolvimento reduzido do isolado CG138 na cutícula de larvas foi observado pela microscopia eletrônica de varredura.

Ocurrencia natural de hongos entomopatógenos en suelos cultivados con yerba mate (Ilex paraguariensis St. Hil.) en Misiones, Argentina / Natural ocurrence of entomopathogenic fungi in soils cultivated with Paraguay tea (Ilex paraguariensis St. Hil.) in Misiones, Argentina

Este trabajo tuvo por objetivo aislar, identificar y caracterizar morfológicamente hongos entomopatógenos presentes en suelos cultivados con yerba mate (Ilex paraguariensis St. Hil.). Se realizó una prospección de hongos entomopatógenos nativos a partir de 40 muestras de suelos cultivados con yerba mate ubicados en la provincia de Misiones, República Argentina, desde mayo de 2008 hasta junio de 2010. Las muestras de suelo se obtuvieron en cercanías de plantas de yerba mate, se aplicó la técnica de dilución seriada en medios de cultivos selectivos. Después de obtenidos los cultivos puros, los hongos fueron caracterizados macroscópica y microscópicamente, y se los identificó mediante el uso de claves taxonómicas específicas. Se aislaron 29 cepas fúngicas pertenecientes a las especies Beauveria bassiana (n = 17), Metarhizium anisopliae (n = 2) y Purpureocillium lilacinum (n = 10)

This study aimed to morphologically isolate, identify and characterize entomopathogenic fungi present in soils cultivated with Paraguay tea (Ilex paraguariensis). A survey of native entomopathogenic fungi was conducted from 40 soil samples grown with Paraguay tea in the province of Misiones, Argentina, from May 2008 to June 2010. The soil dilution plate methodology on selective culture media was used to isolate microorganisms. Taxonomic identification was performed using macroscopic and microscopic characters and specific keys. Twenty nine strains, belonging to the species Beauveria bassiana (n = 17), Metarhizium anisopliae (n = 2) and Purpureocillium lilacinum (n = 10) were isolated and identified

Effect of surfactants and temperature on germination and vegetative growth of Beauveria bassiana

Three non-ionic surfactants: Tween20, Tween80 and Breakthru® were screened for their effects on spore germination and mycelial growth rates and for their influence on three isolates of Beauveria bassiana spore germination at various temperatures. Tween20 and Tween80 were compatible with all the B. bassiana isolates in the germination studies, but inhibited germination at higher surfactant concentrations, irrespective of the conidial concentrations. Breakthru® had an inhibitory effect on germination even at the lowest concentration of 0.1% on all the B. bassiana isolates. The effects of the surfactants on spore germination did not correspond with their effects on colony growth. Conidial viability within the same formulation declined significantly with increases in temperature, irrespective of the surfactant. The optimal temperature for conidial germination of B. bassiana isolates was approximately 25 °C with an upper limit at 30 °C. Isolate 7320 was identified as the least affected by the different surfactants. This isolate was able to germinate rapidly in a broad temperature range of 25–30 °C after 24 h, this characteristic being an essential factor in controlling house fly populations in poultry houses.

Beauveria Bassiana - A Potential Entomopathogen Against Rice Hispa, Dicladispa Armigera.

As such in search of alternative to chemical insecticides against insect pest of rice resulted in identifying white muscardine fungus, Beauveria bassiana an entomopathogen out of several entomogenous fungi prevalent in rice ecosystem as the potential mycoinsecticides. The fungus has 78-87% virulence against rice hispa with LC 50 value of 90.16. Under field situations it is required that the effectiveness of the bioagents is enhanced by combining them with compatible pesticides. A sublethal dose of a pesticide would make the insect physiologically weak which makes it much more susceptible to the attack of the entomogenous organisms. In view of this, compatibility test was conducted with 14 different commonly applied insecticides at two different doses i.e., recommended and half of the recommended dose. In small scale field trial chloropyriphos at half of the recommended dose along with B. bassiana was the best treatment in controlling the pest along with increased yield of the crop consecutively for two years. Similarly, in multilocational field demonstration trial conducted in hispa endemic areas of Assam viz., Sibsagar and Jorhat covering six different localities B. bassiana (@ 10 million spore/ml dilution) and half of the recommended dose of chlorpyriphos proved superiority then the commonly applied insecticides in decreasing the pest population with increased yield of crop.

Liquid production of entomopathogenic fungi and ultraviolet radiation and temperature effects on produced propagules / Produção líquida de fungos entomopatogênicos e efeitos da radiação ultravioleta e da temperatura sobre os propágulos produzidos

The purpose of this paper was to evaluate the liquid culture media for the production of Metarhizium anisopliae (IBCB 425) and Beauveria bassiana (IBCB 66), as well as the tolerance of these seedlings to the ultraviolet action and to the temperature. Twelve treatments composed of combinations between carbon and nitrogen concentrations were assessed. In order to determine the effect of ultraviolet radiation, plates with blastos-pores were exposed to it for 25 and 50 seconds. To determine the temperature efect, blastospores from culture media were exposed to 20, 25, 30 and 35°. For the virulence experiments, caterpillars of Diatraea saccharalis were sprayed with 2 mL of fungal suspension with the aid of a Potter tower. Te best media for M. anisopliae are 16.00 g (carbon) + 7.00 g (nitrogen) and 14.40 g (carbon) + 7.00 g (nitrogen), whereas for B. bassiana: 20.00 g (carbon) + 6.30 g (nitrogen) and 20.00 g (carbon) + 7.00 g (nitrogen). Te longer the exposure to ultraviolet radiation, the smaller the number of colonies. At 35°, there is a significant decrease in the formation of colonies. Te produced seedlings of fungi are pathogenic to D. saccharalis.(AU)

O objetivo deste trabalho foi avaliar os meios de cultura líquidos para a produção de Metarhizium anisopliae (IBCB 425) e Beauveria bassiana (IBCB 66), bem como a tolerância desses propágulos à ação dos raios ultravioleta e à temperatura. Foram avaliados 12 tratamentos compostos pelas combinações entre carbono e nitrogênio. Para determinar o efeito da radiação ultravioleta, placas com blastósporos foram expostas à radiação por 25 e 50 segundos. Para conhecer o efeito da temperatura, os blastósporos de meios de cultura foram expostos a temperaturas de 20, 25, 30 e 35°. Para os experimentos de virulência, as lagartas Diatraea saccharalis foram pulverizadas com 2mL de suspensão fúngica, com o auxílio de uma torre de Potter. Os melhores meios para M. anisopliae são 16,00 g (carbono) + 7,00 g (nitrogênio) e 14,40 g (carbono) + 7,00 g (nitrogênio), e para B. bassiana, 20,00 g (carbono) + 6,30 g (nitrogênio) e 20,00 g (carbono) + 7,00 g (nitrogênio). Quanto mais tempo de exposição à radiação ultravioleta, menor o número de colônias. Aos 35°, há uma diminuição signifcativa na formação de colônias. Os propágulos produzidos pelos fungos são patogênicos a D. saccharalis.(AU)

Immobilization of Beauveria bassiana Lipase on Silica Gel by Physical Adsorption

Extracellular lipase from Beauveria bassiana strain CG481 was immobilized by using thirteen different immobilization protocols. Silica gel was chosen as the most suitable adsorbent with 94.8% of activity yield. The adsorption on silica gel did not change the optimum pH (8.5) and temperature (45ºC) values of the free lipase (FL) for lipolytic activity, and it showed higher activities in extreme conditions (pH 9.0 to 10.5, 60ºC). The lipase immobilized on silica gel (ILS) showed enhanced stability at pH 7.0 after 120 h incubation (69.0%) when compared to FL (33.3%). The thermal stability was also enhanced by immobilization at 60ºC in aqueous (64.6%) and organic medium (95.1%), while FL showed only 40.6% of residual activity in aqueous medium and exhibited no activity for esterification reaction in n-heptane. The treatment of ILS with 0.8 M NaCl prevented lipase desorption while Triton X-100 (0.1%) resulted the enzyme leakage. The ILS was reused for four times for esterification reaction with 80.8% of initial activity.

Production of Beauveria bassiana Air Conidia by Means of Optimization of Biphasic System Technology

Air conidia production of Beauveria bassiana, strain CA-603 was studied based on modified diphasic system. The biomass yield obtained in the first phase based on submerged cultivation of fungus was processed using methodology providing different contact with air space. Our study indicated that productivity of the second stage of diphasic system is had inversely proportional dependence on depth of liquid fungal biomass. Increase of biomass depth is significantly decreased production of air conidia. Two methodology of biomass processing extending contact biomass with air space including distribution of fungal material on surface of hygroscopic paper and starch packaging peanuts were investigated. The novel substrates provided optimal contact between the submerged fungal biomass and the air, and overall, conidial production was directly proportional to the total area of air-to-fungal surface. Technologies based on the starch peanuts and hygroscopic paper were the most productive in comparison to the common technology where the submerged culture was transferred to flat containers. The advantages and disadvantages of these different production methods are discussed.