Biochemistry and Molecular Biology of Entomopathogenic Fungi

Khachatourians, George G.

doi:10.1007/978-3-662-10373-9_17

Cited by 54 publications

(56 citation statements)

References 204 publications

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“…The potential application of fungal pathogens as control agents against insect pests is also well documented (Roberts and Hajek, 1992;Clarkson and Charnley, 1996;Khachatourians, 1996;Shah and Pell, 2003;Faria and Wraight, 2007). Unlike other insectpathogenic microorganisms, which must be ingested to initiate disease (e.g.…”

Section: Introductionmentioning

confidence: 99%

The antimicrobial activity of the alcohols fromMusca domestica

Gołębiowski

Dawgul

Kamysz

et al. 2012

Journal of Experimental Biology

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SUMMARYInformation on the stimulatory and inhibitory effects of cuticular alcohols on growth and virulence of insecticidal fungi is unavailable. Therefore, we set out to describe the content of cuticular and internal alcohols in the body of housefly larvae, pupae, males and females. The total cuticular alcohols in larvae, males and females of Musca domestica were detected in comparable amounts (4.59, 3.95 and 4.03gg -1 insect body, respectively), but occurred in smaller quantities in pupae (2.16gg -1). The major free alcohol in M. domestica larvae was C 12:0 (70.4%). Internal alcohols of M. domestica larvae were not found. Among cuticular pupae alcohols, C 12:0 (31.0%) was the most abundant. In the internal lipids of pupae, only five alcohols were identified in trace amounts. The most abundant alcohol in males was C 24:0 (57.5%). The percentage content of cuticular C 24:0 in males and females (57.5 and 36.5%, respectively) was significantly higher than that of cuticular lipids in larvae and pupae (0.9 and 5.6%, respectively). , respectively). For isolated alcohols, antimicrobial activity against 10 reference strains of bacteria and fungi was determined. Individual alcohols showed approximately equal activity against fungal strains. C 14:0 was effective against gram-positive bacteria, whereas gram-negative bacteria were resistant to all tested alcohols. Mixtures of alcohols found in cuticular lipids of larvae, pupae, males and females of M. domestica generally presented higher antimicrobial activity than individual alcohols. In contrast, crude extracts containing both cuticular and internal lipids showed no antifungal activity against the entomopathogenic fungus Conidiobolus coronatus, which efficiently kills adult house flies. Only two alcohols were present in the internal lipids of males in trace amounts

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Section: Introductionmentioning

confidence: 99%

The antimicrobial activity of the alcohols fromMusca domestica

Gołębiowski

Dawgul

Kamysz

et al. 2012

Journal of Experimental Biology

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“…Entomopathogenic fungi (EF) are the main biological agents used in integrated pest management systems. To date, more than 750 species of entomopathogenic fungi belonging to almost 100 genera have been identified, most of which are classified among the Zigomicota (entomoptera), Deuteromicota (hyphomycetes) and Ascomicota (Roberts, 1989;Hegedus and Khachatourians, 1995;Khachatourians, 1996). However, only 10 of them have been or are currently being used in commercial or experimental insect control formulations (Lacey et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

“…A review of the literature in recent decades shows that a considerable number of low molecular weight secondary metabolites isolated from insect pathogens have proved to have insecticidal activity (Gilliespie and Claydon, 1989). Many secondary metabolites produced by entomopathogenic fungi are common to several of them and have been detected in most cases by their in vitro production, which is significantly affected by the conditions and composition of the culture medium (Khachatourians, 1996). Nomuraea rileyi (Farlow) Samson has been reported as a pathogen of more than 30 species of lepidopteran larvae, especially when they are in humid weather conditions (Devi et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Insecticidal activities of diketopiperazines of Nomuraea rileyi entomopathogenic fungus

Marcinkevicius¹,

Salvatore²,

Bardón³

et al. 2017

IJEAB

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Abstract-Entomopathogenic fungi are fungal organisms extensively used in various parts of the world as biopesticides against insect pests that cause important economic damage. Various secondary metabolites produced by these fungi have many potential biological activities. The present study was undertaken to evaluate the insecticidal activity of extracts and pure compounds from Nomuraea rileyi (Farlow) Samson entomopathogenic fungi against Spodoptera frugiperda Smith (Lepidoptera), Ceratitis capitata Wiedemann (Diptera) and Tribolium castaneum Herbst (Coleoptera), three insect pests that generate serious economic losses in the northwest of Argentina. Diketopiperazines were extracted from the culture free supernatant of the media with ethyl acetate. Antifeedant properties were detected in all extracts under dietary choice conditions (300 ug/ g of diet). The maximum antifeedant activity was noted in cycles (Pro-Val) (86.02) and cycle (Pro-Phe) (73.47), while the rest of the extracts and metabolites exhibited varying degrees of moderate or less toxic effects. The maximum oviposition deterrence against C. capitata (55.86%) was recorded with cycle (Pro-Phe) at a 50 µm/cm 2 dose. Culture medium extracts supplemented with insect remains and all pure compounds showed repellent action against T. castaneum. The main repellency was observed in phenylacetic acid and cycle (Pro-Val) with RI values of 42 and 41% respectively. The present study would suggest the possible utilization of entomopathogenic fungal metabolites as an effective agent for controlling insect pests that cause important economic losses.

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“…Estes fungos apresentam vantagens, em relação a outros agentes microbianos do controle biológico, porque não necessitam ser ingeridos para causar doença nos insetos (ALVES, 1998). A infecção ocorre por adesão dos conídios fúngicos, e subsequente penetração da cutícula protetora dos insetos devido à produção de enzimas extracelulares e pressão mecânica exercida pelas estruturas de reprodução dos conídios (KHACHATOURIANS, 1996). Proteases e quitinases têm sido aceitas como os principais fatores determinantes da virulência dos fungos entomopatogênicos (St. LEGER et al, 1986b), pois hidrolisam os principais polímeros constituintes da cutícula, proteínas e quitina, organizados em camadas denominadas exo e endocutícula.…”

Section: Introductionunclassified

Avaliação de parâmetros cinéticos de quitinases produzidas por Beauveria bassiana (Bals.) Vuill.

et al. 2008

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ResumoBeauveria bassiana é um fungo entomopatogênico utilizado no controle biológico de insetos-praga que infestam produtos agrícolas. O mecanismo de infecção envolve a produção de enzimas extracelulares, como proteases e quitinases que degradam a cutícula dos insetos. O objetivo deste trabalho foi avaliar parâmetros cinéticos de pH, temperatura, concentração iônica e tempo de reação sobre a atividade de quitinases. O fungo B. bassiana CG432 foi repicado em broca do café Hypothenemus hampei (Ferrari) e utilizado para preparar o inóculo contendo 10 8 conídios ativados/mL. Estes conídios foram inoculados 1% (v/v) em meio de cultura líquido constituído por D-glicose (10g), extrato de levedura (5g), NaNO 3 (1,58g) , Na 2 HPO 4 .7H 2 O (1,05g), KCl (1g), MgSO 4 .7H 2 O (0,6g) e KH 2 PO 4 (0,36g) por litro. O cultivo foi conduzido a 28°C e 180rpm durante 5 dias. O fluido extracelular do cultivo foi obtido por filtração e centrifugação a 8.000g, e as quitinases foram isoladas e concentradas por ultrafiltração entre membranas de 10 e 100kDa sob pressão de nitrogênio. A atividade das quitinases foi determinada pela quantificação da N-acetilglicosamina liberada pela hidrólise da quitina coloidal durante 60 minutos de incubação a temperaturas de 40 a 60ºC, concentrações iônicas dos tampões acetato de sódio pH 4,0 a 6,0; fosfato de sódio pH 6,0 a 8,0; e glicina-NaOH pH 8,0 a 10,0, a 50, 100 e 200 mM. A atividade das quitinases foi máxima a 45ºC, em pH 5,5, mas também foi elevada em pH 6,0 e 8,5 em concentração iônica de 50mM. A atividade de quitinases aumentou durante uma hora de incubação demonstrando estabilidade das enzimas nas condições ótimas da reação. Palavras-chave: Fungos entomopatogênicos; Biocontrole; Hypothenemus hampei. AbstractEntomopathogenic fungus Beauveria bassiana is currently used as a biocontrol agent for agricultural pests. The infection process involves extracellular enzymes such as proteases and chitinases that degrade the cuticle of the insects. The objective of this work was to evaluate kinetic parameters of pH, temperature, ionic concentration and time of reaction on chitinases activity. The fungus B. bassiana CG432 was cultivated on coffee berry borer Hypothenemus hampei (Ferrari) and the conidia grown on insect were used to prepare the inoculum containing 10 8 conídia/mL. These conidia were inoculated at 1% (v/v) in

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Biochemistry and Molecular Biology of Entomopathogenic Fungi

Cited by 54 publications

References 204 publications

The antimicrobial activity of the alcohols fromMusca domestica

The antimicrobial activity of the alcohols fromMusca domestica

Insecticidal activities of diketopiperazines of Nomuraea rileyi entomopathogenic fungus

Avaliação de parâmetros cinéticos de quitinases produzidas por Beauveria bassiana (Bals.) Vuill.

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