Entomopathogenic fungi, such as Metarhizium anisopliae, are able to control various insect pests. These fungi attack the integument of the host using an enzymatic complex. Among the enzymes found in this complex, chit...Entomopathogenic fungi, such as Metarhizium anisopliae, are able to control various insect pests. These fungi attack the integument of the host using an enzymatic complex. Among the enzymes found in this complex, chitinase is an important component. However, the relation between the chitinase production and the virulence from different M. anisopliae strains has not been analyzed. In this manuscript it is presented the chitinase production by four M. anisopliae strains with different potential of virulence in Solid-State Fermentation using silkworm chrysalis as substrate. The higher chitinase level was obtained with the strain IBCB 360 (7.14 U/g of substrate) with potential virulence of 68% on Diatrea saccharalis. The enzyme production was optimized for all strains using a factorial planning (CCRD) considering the cultivation time and medium humidity as independent variables. The maximal production of chitinase was obtained at a range from 8 to 12-days old cultures and from 45% to 62% of moisture according to the surface response plot, with high R2 value. The enzyme production by the strain IBCB 167 was increased two-folds under optimized conditions, while for the strains IBCB 360 and 425 the chitinase production was increased four-folds and nine-folds for the strain IBCB 384.展开更多
Developing appropriate control measures for the Mahogany shoot borer,Hypsipyla robusta Moore has become increasingly important due to the severe damaging effect of the pest on the establishment of the saplings of Swie...Developing appropriate control measures for the Mahogany shoot borer,Hypsipyla robusta Moore has become increasingly important due to the severe damaging effect of the pest on the establishment of the saplings of Swietenia mahagoni Jacq(Sapindales:Meliaceae).Existing management methods are largely limited to silvicultural practices and spraying of chemical insecticides.To identify a potential fungal biocontrol agent,we compared the virulence of six native and two standard ARSEF isolates of Metarhizium anisopliae Metsch.against this pest.The average survival time and conidial yield of IWST-Ma7 was higher(6.2 to 7.3 days and 4.9 to 4.7 × 10 5 conidia/ml) than the standards.Significant difference in sporulation on the cadavers between isolates,doses and incubation periods were substantiated for the selection of potential strain.The mycotoxic effects of crude soluble protein extract when incorporated in the artificial diet,the ARSEF 2596 and ARSEF 3603 showed LD 50 value of 3.7% and 5.6%.However,IWST-Ma7 was highly lethal with significant lowest LD 50 value of 2.6%.The enzyme activity of IWST-Ma7 was highest for chitinase,CDA,protease and lipase viz.,1.90 U/mg,1.80 U/mg,0.98 U/mg and 0.80 U/mg respectively.However the enzyme activity of chitinase and Chitin deacetylase assay for all the isolates was significantly higher than protease and lipase activity.The ITS regions(5.8S rDNA and 28S rDNA) of seven isolates of M.anisopliae were amplified using the ITS1 and ITS4 primers which was a unique fragment of approximately 550 bp.Based on ITS regions,phylogenetic tree have been constructed and the isolates have been grouped in to 5 clades.The virulence and mycotoxic effects of different isolates could rationally be used to employ them for the management of the mahogany borer.展开更多
Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was used to examine the genetic variability among Metarhizium anisopliae isolates tested to the cossid moth, Coryphodema tristis. All the isolates ...Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was used to examine the genetic variability among Metarhizium anisopliae isolates tested to the cossid moth, Coryphodema tristis. All the isolates tightly clustered into one or the other of two groups that diverged at 12%. Results suggested that certain genotypes of the fungus, that grouped together, were able to infect moth larvae while others did not. A fragment of 760 bp, which presents high homology with a host-adaptation related protein coding gene, distinguished between aggressive and non-aggressive isolates. Neither mycelial growth nor sporulation rate or presence of known virulence genes was correlated with mortality values. Some isolates, including the most aggressive isolate ARSEF2518, were compatible with deltamethrin. Deltamethrin treatment killed all the larvae after seven days whereas fungal and mixed treatments respectively reached the same mortality after 28 and 21 days.展开更多
Metarhizium anisopliae as an essential entomopathogenic fungus has been known to produce destruxins(a kind of cyclo-peptidic mycotoxins) and blastospores in submerged culture. Blastospores and destruxins are candidate...Metarhizium anisopliae as an essential entomopathogenic fungus has been known to produce destruxins(a kind of cyclo-peptidic mycotoxins) and blastospores in submerged culture. Blastospores and destruxins are candidates for insecticides, but the relations of both productions and the impact factors are unclear yet. In this study, we investigated the effects of inoculums, rotation, dissolved oxygen(DO) on the productions of blastospores and destruxins A and B(DA and DB) in submerged culture of M. anisopliae strain Ma Q01. The results indicated that DO levels were regulated by inoculum amounts and rotation speeds, meanwhile, the productions of DA, DB and blastospores were also closely influenced by those factors. Totally, when DO value was more than 40%, the higher productions of destruxins and blastospores were achieved, by contrast, lower than 40% of DO values resulted in lower productions. The regression analysis suggested that the productions of DA, DB and blastospores were positively correlated with the DO levels. Meanwhile, the positive correlations between the productions of DA or DB and blastospores were also found. Briefly, when the rotation is 150 r min–1 and the inoculum is 1.0×10~6 spore m L^(–1), the DA, DB and blastospores achieved the best production of 61.81 mg m L^(–1), 24.74 mg m L^(–1) and 5.73×10~6 spore m L^(–1), respectively. In addition, the pathogenicities of blastospores and conidia against Plutella xylostella were bioassayed. The higher mortalities of P. xylostella were totally recorded in blastospore treatments than in conidia treatments, especially in lower dosages and earlier periods. Our research will give some new insights to production of destruxins and blastospores by using M. anisopliae.展开更多
Plant diseases generate challenging problems in commercial, agriculture and pose real economic threats to both conventional and organic farming systems. The red palm weevil (Rhynchophorus ferrugineus) (RPW) is one of ...Plant diseases generate challenging problems in commercial, agriculture and pose real economic threats to both conventional and organic farming systems. The red palm weevil (Rhynchophorus ferrugineus) (RPW) is one of the most destructive pests of palms in the world. Nowadays, control methods revolve around treatments based on chemicals, biotechnological systems using semi-chemicals or the development of the sterile insect technique (hardly sustainable at this time) and biological control. Biological control as the use of natural microorganisms, extracted products from microorganisms or genetically improved to resist or eliminate of pathogens. Our aim was to evaluate the entomopathogenicity of indigenous Beauveria bassiana and Metarhizium anisopliae obtained in Gaza strip against larvae and adults of R. ferrugineus in order to identify indigenous strains potentially suitable for Red Palm Weevil biological control. B. bassiana & M. anisopliae were isolated from larvae and adult dead of RPW from different position of Gaza strip. Morphological analysis of the isolated fungi and molecular identification was determined using PCR technique. Also, the efficiency of the isolated fungi were evaluated under lab conditions and optimized as a biological agent. On the anther hand, the ability of treated RPW male to infect females is examined and calculated using Abbott's formula. Our results showed that the B. bassiana and M. anisopliae exhibited a good biological control agent against larvae and adults of RPW. The pathogenicity of the two most virulent isolates and the toxicity assay on larvae showed a highest mortality percentage nearly to 100% by 6 days after spraying the larvae with 3.4 × 108 spores/ml of B. bassiana. The mortality percentage reaches to 90% after spraying the larvae with 3.6 × 108 spores/ml of M. anisopliae. The mortality for the adults treated with pesticide arrives to 50% and the control group 10% at the same time. The results revealed that the infection of the adult males by Entomopathogenic fungi (EPF) can be disseminated into the healthy population, after RPW treatment with B. bassiana and M. anisopliae. Our research concludes that B. bassiana and M. anisopliae locally isolated can be used as biological very effective.展开更多
MetarhizosidesA-G(1-7),seven new polysubstituted phenyl glucosides,were isolated from the extracts of solid rice medium of a marine-derived fungus Metarrhizium anisopliae.Compounds 1-7 all contain a polysubstituted ph...MetarhizosidesA-G(1-7),seven new polysubstituted phenyl glucosides,were isolated from the extracts of solid rice medium of a marine-derived fungus Metarrhizium anisopliae.Compounds 1-7 all contain a polysubstituted phenyl group and the sugar unit is identified as 4'-O-methyl-β-D-glucopyranose.Their structures were elucidated by NMR spectroscopy and chemical method.These compounds were evaluated for anti-inflammatory activity by using LPS-stimulated murine macrophage RAW 264.7 cells and the cytotoxicities against four human cancer cell lines.展开更多
Rice flour,puparium of yellow mealworm,peanut shell and sunflower seed shell are made into the culture medium,and the optimal solid-phase fermentation formula for M. flavoviride is figured out. In the solid-phase ferm...Rice flour,puparium of yellow mealworm,peanut shell and sunflower seed shell are made into the culture medium,and the optimal solid-phase fermentation formula for M. flavoviride is figured out. In the solid-phase fermentation,Design-Expert is applied to analyze the significance of all components on the sporulation,and response surface method used to optimize the fermentation medium of M. flavoviride. The results show that puparium of yellow mealworm is the most significant component for the sporulation; and the optimal medium formula for the fermentation of M. flavoviride: 0. 25-g rice flour,0. 14-g yellow mealworm puparium,1. 00-g peanut shell,and 0. 25-g sunflower seedshell. In this optimal medium,the sporulation achieves 100. 013 × 108 spores / m L fungal liquid,31. 7% higher than that of the initial design. Application of the optimal formula will reduce the production cost,obtain higher yield of spores,produce no pollution,and offer technical support for the future large-scale production.展开更多
基金supported by Fundacao de Apoio a Pesquisa do Estado de Sao Paulo(FAPESP)and Coor-denadoria de Apoio ao Ensino Superior(CAPES).
文摘Entomopathogenic fungi, such as Metarhizium anisopliae, are able to control various insect pests. These fungi attack the integument of the host using an enzymatic complex. Among the enzymes found in this complex, chitinase is an important component. However, the relation between the chitinase production and the virulence from different M. anisopliae strains has not been analyzed. In this manuscript it is presented the chitinase production by four M. anisopliae strains with different potential of virulence in Solid-State Fermentation using silkworm chrysalis as substrate. The higher chitinase level was obtained with the strain IBCB 360 (7.14 U/g of substrate) with potential virulence of 68% on Diatrea saccharalis. The enzyme production was optimized for all strains using a factorial planning (CCRD) considering the cultivation time and medium humidity as independent variables. The maximal production of chitinase was obtained at a range from 8 to 12-days old cultures and from 45% to 62% of moisture according to the surface response plot, with high R2 value. The enzyme production by the strain IBCB 167 was increased two-folds under optimized conditions, while for the strains IBCB 360 and 425 the chitinase production was increased four-folds and nine-folds for the strain IBCB 384.
文摘Developing appropriate control measures for the Mahogany shoot borer,Hypsipyla robusta Moore has become increasingly important due to the severe damaging effect of the pest on the establishment of the saplings of Swietenia mahagoni Jacq(Sapindales:Meliaceae).Existing management methods are largely limited to silvicultural practices and spraying of chemical insecticides.To identify a potential fungal biocontrol agent,we compared the virulence of six native and two standard ARSEF isolates of Metarhizium anisopliae Metsch.against this pest.The average survival time and conidial yield of IWST-Ma7 was higher(6.2 to 7.3 days and 4.9 to 4.7 × 10 5 conidia/ml) than the standards.Significant difference in sporulation on the cadavers between isolates,doses and incubation periods were substantiated for the selection of potential strain.The mycotoxic effects of crude soluble protein extract when incorporated in the artificial diet,the ARSEF 2596 and ARSEF 3603 showed LD 50 value of 3.7% and 5.6%.However,IWST-Ma7 was highly lethal with significant lowest LD 50 value of 2.6%.The enzyme activity of IWST-Ma7 was highest for chitinase,CDA,protease and lipase viz.,1.90 U/mg,1.80 U/mg,0.98 U/mg and 0.80 U/mg respectively.However the enzyme activity of chitinase and Chitin deacetylase assay for all the isolates was significantly higher than protease and lipase activity.The ITS regions(5.8S rDNA and 28S rDNA) of seven isolates of M.anisopliae were amplified using the ITS1 and ITS4 primers which was a unique fragment of approximately 550 bp.Based on ITS regions,phylogenetic tree have been constructed and the isolates have been grouped in to 5 clades.The virulence and mycotoxic effects of different isolates could rationally be used to employ them for the management of the mahogany borer.
文摘Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was used to examine the genetic variability among Metarhizium anisopliae isolates tested to the cossid moth, Coryphodema tristis. All the isolates tightly clustered into one or the other of two groups that diverged at 12%. Results suggested that certain genotypes of the fungus, that grouped together, were able to infect moth larvae while others did not. A fragment of 760 bp, which presents high homology with a host-adaptation related protein coding gene, distinguished between aggressive and non-aggressive isolates. Neither mycelial growth nor sporulation rate or presence of known virulence genes was correlated with mortality values. Some isolates, including the most aggressive isolate ARSEF2518, were compatible with deltamethrin. Deltamethrin treatment killed all the larvae after seven days whereas fungal and mixed treatments respectively reached the same mortality after 28 and 21 days.
基金supported by the Special Fund for Forest Scientific Research in the Public Welfare (201304408)the Open Fund of Key Laboratory of Forest Diseases and Insect Pests in Guangdong Province, China
文摘Metarhizium anisopliae as an essential entomopathogenic fungus has been known to produce destruxins(a kind of cyclo-peptidic mycotoxins) and blastospores in submerged culture. Blastospores and destruxins are candidates for insecticides, but the relations of both productions and the impact factors are unclear yet. In this study, we investigated the effects of inoculums, rotation, dissolved oxygen(DO) on the productions of blastospores and destruxins A and B(DA and DB) in submerged culture of M. anisopliae strain Ma Q01. The results indicated that DO levels were regulated by inoculum amounts and rotation speeds, meanwhile, the productions of DA, DB and blastospores were also closely influenced by those factors. Totally, when DO value was more than 40%, the higher productions of destruxins and blastospores were achieved, by contrast, lower than 40% of DO values resulted in lower productions. The regression analysis suggested that the productions of DA, DB and blastospores were positively correlated with the DO levels. Meanwhile, the positive correlations between the productions of DA or DB and blastospores were also found. Briefly, when the rotation is 150 r min–1 and the inoculum is 1.0×10~6 spore m L^(–1), the DA, DB and blastospores achieved the best production of 61.81 mg m L^(–1), 24.74 mg m L^(–1) and 5.73×10~6 spore m L^(–1), respectively. In addition, the pathogenicities of blastospores and conidia against Plutella xylostella were bioassayed. The higher mortalities of P. xylostella were totally recorded in blastospore treatments than in conidia treatments, especially in lower dosages and earlier periods. Our research will give some new insights to production of destruxins and blastospores by using M. anisopliae.
文摘Plant diseases generate challenging problems in commercial, agriculture and pose real economic threats to both conventional and organic farming systems. The red palm weevil (Rhynchophorus ferrugineus) (RPW) is one of the most destructive pests of palms in the world. Nowadays, control methods revolve around treatments based on chemicals, biotechnological systems using semi-chemicals or the development of the sterile insect technique (hardly sustainable at this time) and biological control. Biological control as the use of natural microorganisms, extracted products from microorganisms or genetically improved to resist or eliminate of pathogens. Our aim was to evaluate the entomopathogenicity of indigenous Beauveria bassiana and Metarhizium anisopliae obtained in Gaza strip against larvae and adults of R. ferrugineus in order to identify indigenous strains potentially suitable for Red Palm Weevil biological control. B. bassiana & M. anisopliae were isolated from larvae and adult dead of RPW from different position of Gaza strip. Morphological analysis of the isolated fungi and molecular identification was determined using PCR technique. Also, the efficiency of the isolated fungi were evaluated under lab conditions and optimized as a biological agent. On the anther hand, the ability of treated RPW male to infect females is examined and calculated using Abbott's formula. Our results showed that the B. bassiana and M. anisopliae exhibited a good biological control agent against larvae and adults of RPW. The pathogenicity of the two most virulent isolates and the toxicity assay on larvae showed a highest mortality percentage nearly to 100% by 6 days after spraying the larvae with 3.4 × 108 spores/ml of B. bassiana. The mortality percentage reaches to 90% after spraying the larvae with 3.6 × 108 spores/ml of M. anisopliae. The mortality for the adults treated with pesticide arrives to 50% and the control group 10% at the same time. The results revealed that the infection of the adult males by Entomopathogenic fungi (EPF) can be disseminated into the healthy population, after RPW treatment with B. bassiana and M. anisopliae. Our research concludes that B. bassiana and M. anisopliae locally isolated can be used as biological very effective.
基金This work was financially supported by the Program for Changjiang Scholars of Ministry of Education of the People's Republic of China(No.T2016088)the National Natural Science Foundation for Distinguished Young Scholars(No.81725021)+2 种基金the National Natural Science Foundation of China(No.31900288)the Program from the(hina Postdoctoral Science Foundation(No.2019M652660)the Integrated Innovative Team for Major Human Diseases Program of Tongji Medical College(HUST,China).
文摘MetarhizosidesA-G(1-7),seven new polysubstituted phenyl glucosides,were isolated from the extracts of solid rice medium of a marine-derived fungus Metarrhizium anisopliae.Compounds 1-7 all contain a polysubstituted phenyl group and the sugar unit is identified as 4'-O-methyl-β-D-glucopyranose.Their structures were elucidated by NMR spectroscopy and chemical method.These compounds were evaluated for anti-inflammatory activity by using LPS-stimulated murine macrophage RAW 264.7 cells and the cytotoxicities against four human cancer cell lines.
基金Sponsored by Anhui Province Natural Science Foundation(1408085QC52)Science and Technology Key Projects of China Tobacco Corporation(IPM-201411)
文摘Rice flour,puparium of yellow mealworm,peanut shell and sunflower seed shell are made into the culture medium,and the optimal solid-phase fermentation formula for M. flavoviride is figured out. In the solid-phase fermentation,Design-Expert is applied to analyze the significance of all components on the sporulation,and response surface method used to optimize the fermentation medium of M. flavoviride. The results show that puparium of yellow mealworm is the most significant component for the sporulation; and the optimal medium formula for the fermentation of M. flavoviride: 0. 25-g rice flour,0. 14-g yellow mealworm puparium,1. 00-g peanut shell,and 0. 25-g sunflower seedshell. In this optimal medium,the sporulation achieves 100. 013 × 108 spores / m L fungal liquid,31. 7% higher than that of the initial design. Application of the optimal formula will reduce the production cost,obtain higher yield of spores,produce no pollution,and offer technical support for the future large-scale production.
