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Impact of water relations on the production, ecological fitness and stability of the biocontrol fungus Metarhizium anisopliae

By Ioannis K. Ypsilos

Abstract

The aim of this work was the production of high numbers of propagules of the entomopathogenic fungus Metarhizium anisopliae with high germination capacity under low water availability, good storage stability and enhanced pathogenicity. To this end modifications of cultural conditions were employed. Water-stress in solid substrate fermentation reduced the conidial production but resulted in enhancement of germination capacity. Conidial production and germination was also considerably influenced by the type of solid substrate (bulgar wheat, millet grain). Intracellular accumulation of endogenous reserves of selected polyols, which have been linked with enhancement of germination under conditions of restricted water availability, was altered by such substrate modifications. Imposed water-stress in liquid culture resulted in increased blastospore production in the 0.998 to 0.96 water activity (a. ) range when ionic solutes (NaCl, KCI) were used for medium modification but when PEG 200 was used, this range was narrower (0.998-0.98 aw). Water-stress resulted in the production of modified blastospores with increased levels of the low molecular weight polyol erythritol. Higher amounts of endogenous polyols were retained intracellularly when modified blastospores were harvested in isotonic solutions compared to those subjected to hypo-osmotic shock by washing with water. Intracellular polyol patterns of blastospores were also affected by nitrogen source, pH and aW-modifying solute as well as by interaction between these factors. Optimum conditions for increased erythritol accumulation occurred when ionic solutes (NaCl, KCl) were used for aW modification and in the pH range between 6.8-8. Total endogenous protein was also enhanced under the same conditions. Germination of blastospores produced under these conditions was between 62-89% under conditions of water-stress (0.96 a, ). In contrast, blastospores with lower amounts of erythritol and total protein content had decreased germination (8- 67%). Osmoprotection of such modified blastospores resulted in increased storage stability as wet pastes and as freeze-dried preparations. Fluidised bed dried blastospores had either decreased viability (<25%) or good viability (>40%) but high conent of moisture (>30%). Destruxin A production was not affected by osmoprotection whereas protease activity was enhanced by isotonic washing with PEG 200 solution but not by. ionic (NaCl) or carbohydrate (glucose) solutions. Modified blastospores were not more infective to aphids than unmodified ones under 100% R. H. regimes

Publisher: Cranfield University
Year: 2004
OAI identifier: oai:dspace.lib.cranfield.ac.uk:1826/4678
Provided by: Cranfield CERES

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Citations

  1. (1997). A rapid HPLC protocol for detection of polyols and trehalose. doi
  2. (1984). A simple method for mass culturing entomopathogenic Hyphomycete fungi. doi
  3. (2000). Accumulation of compatible solutes in Penicillium frequentants grown at reduced water activity and biocontrol of Monilinia laxa. doi
  4. (1982). Accumulation of intracellular solutes by two filamentous fungi in response to growth at low steady state osmotic potential. doi
  5. (2001). Acid phosphatases of Metarhizium anisopliae during infection of the tobacco hornworm Manduca sexta. doi
  6. (1983). Activation of pro-phenoloxidase by bacterial cell walls or ß-1,3 glucans in plasma of the silkworm, Bombyx mori. doi
  7. (2001). Adult survival, maturation, and reproduction of the desert locust Schistocerca gregaria infected with the fungus Metarhizium anisopliae var acridum. doi
  8. (1998). Ambient pH is a major determinant in the expression of cuticle-degrading enzymes and hydrophobin by Metarhizium anisopliae.
  9. (1999). Antifeedant properties of destruxins and their potential use with the entomogenous fungus Metarhizium anisopliae for improved control of crucifer pests. doi
  10. (1997). Antimycotic activity of lysozyme and its contribution to antifungal humoral defence reactions in Galleria mellonella.
  11. (1988). Atlas of Entomopathogenic Fungi. doi
  12. (1991). Attachment of mycopathogens to cuticle; the initial event of mycoses in arthropod hosts. In: doi
  13. (1991). b. Influence of cultural conditions on the virulence of conidia and blastospores of Beauveria bassiana to the green leafhopper, Nephotettix virescens. doi
  14. (1993). Biochemical engineering aspects of solid-state fermentation. doi
  15. (2001). Both solar UVA and UVB radiation impair conidial culturability and delay germination in the entomopathogenic fungus Metarhizium anisopliae. doi
  16. (1986). C-13-NMR studies on the influence of pH and nitrogen source on polyol pool formation in Aspergillus nidulans. doi
  17. (1990). Carbon concentration and carbon-to-nitrogen ratio influence submerged-culture conidiation by the potential bioherbicide Colletotrichum truncatum NRRL-13737.
  18. (1991). Changes in translatable mRNA species associated with nutrient deprivation and protease synthesis in Metarhizium anisopliae. doi
  19. (2003). Characetrization and stability of proteases from Penicillium sp. produced by solid-state fermentation. doi
  20. (1989). Characteristics relating to the pathogenicity of Metarhizium anispoliae toward Nilaparvata lugens. doi
  21. (1970). Chlamydospore development in the absence of protein synthesis in Fusarium solani. doi
  22. (2001). Commercial use of fungi as plant disease biological control agents: Status and prospects. doi
  23. (1995). Comparison of aerial and submerged spore properties for Trichoderma harzianum. doi
  24. (1990). Compatible solutes - the mycological dimension and their role as physiological buffering agents. doi
  25. (1978). Compatible solutes and extreme water stress in eukaryotic microorganisms. doi
  26. (2003). Concurrence of losing a chromosome and the ability to produce destruxins in a mutant of Metarhizium anisopliae. doi
  27. (1991). Conidial biomass and desiccation tolerance of Trichoderma harzianum produced at different medium water potentials. doi
  28. (2000). Conidial germination in Aspergillus nidulans requires RAS signalling and protein synthesis.
  29. (1996). Culture age, temperature, and pH affect the polyol and trehalose contents of fungal propagules.
  30. (1986). Cuticle-degrading enzymes of entomopathogenic fungi: Cuticle degradation in vitro by enzymes from entomopathogens. doi
  31. (1986). Cuticle-degrading enzymes of entomopathogenic fungi: Mechanisms of interaction between pathogen enzymes and insect cuticle. doi
  32. (1986). Cuticle-degrading enzymes of entomopathogenic fungi: regulation of production of chitinolytic enzymes. doi
  33. (1986). Cuticle-degrading enzymes of entomopathogenic fungi: synthesis in culture on cuticle. doi
  34. (2002). Detection and characterisation of prl virulent gene deficiencies in the insect pathogenic fungus Metarhizium anisopliae. doi
  35. (2001). Determination of destruxins, cyclic peptide toxins, produced by different strains of Metarhizium anisopliae and their mutants induced by ethyl methane sulfonate and ultraviolet using HPLC method. doi
  36. (1998). Development of a spray-drying technique for submerged spores of entomopathogenic fungi. doi
  37. (1996). Development of media and automated liquid fermentation methods to produce desiccation-tolerant propagules of Trichoderma harzianum. doi
  38. (1987). Development of the entomopathogenic fungus Beauveria bassiana in liquid cultures. doi
  39. (2001). Drying and formulation of blastospores of Paecilomyces fumosoroseus produced in two different liquid media.
  40. (1990). Dye-labelled substrates for the assay and detection of chitinase and lysozyme activity. doi
  41. (1998). Effect of additives on the production, viability and virulence of blastospores of Metarhizium anisopliae. doi
  42. (1994). Effect of carbohydrate type and concentration on polyhydroxy alcohol and trehalose content of conidia of three entomopathogenic fungi. doi
  43. (2001). Effect of liquid culture media on morphology, growth, propagule production, and pathogenic activity of the Hyphomycete, Metarhizium flavoviride.
  44. (1994). Effect of osmotic potential on the germination of conidia and colony growth of Verticillium lecanii. doi
  45. (1982). Effect of osmotic shock on some intracellular solutes in two filamentous fungi. doi
  46. (2000). Effect of protective agents, rehydration media and initial cell concentration on viability of Pantoca agglomerans strain CPA-2 subjected to freeze-drying. doi
  47. (1986). Effect of water activity on conidial germination and mycelial growth of Beauveria bassiana, Metarhizium anisopliae, Paecilomyces spp. and Verticillium
  48. (2002). Effects of culture age, washing and storage conditions on desiccation tolerance of Colletotrichum truncatum conidia. doi
  49. (1994). Effects of KCl concentration on accumulation of acyclic sugar alcohols and trehalose in conidia of three entomopathogenic fungi. doi
  50. (1996). Effects of moisture content and temperature on storage of Metarhizium flavoviride conidia. doi
  51. (1998). Effects of simulated solar radiation on conidial germination of Metarhizium anisopliae in different formulations. doi
  52. (1986). Effects of water activity and culture age on the glycerol accumulation patterns of five fungi. doi
  53. (1987). Effects of water activity on growth and sporulation of Paecilomyces farinosus in liquid and solid media. doi
  54. (1989). Effects of water activity on morphology, growth and blastospore production of Metarhizium anisopliae, Beauveria bassiana and Paecilomyces farinosus in batch and fed-batch culture. doi
  55. (1991). Endogenous reserves and survival of blastospores of Beauveria bassiana harvested from carbon- and nitrogen-limited batch cultures. doi
  56. (1988). Evaluation of the stain viablue for the rapid estimation of viable yeast cells. doi
  57. (1993). Evasion of host defense by in vivoproduced protoplast-like cells of the insect mycopathogen Beauveria bassiana.
  58. (1999). Fluctuating temperature and the longevity of conidia of Metarhizium flavoviride in storage. doi
  59. (1999). Formulating microbial biocontrol agents. doi
  60. (1997). Formulation: is it an excuse for poor application? In:
  61. (2000). Fungal biopesticide production by solid-state fermentation: growth and sporulation of Coniothyrium minitans. doi
  62. (1997). Fungi in extreme environments. In:
  63. (1999). Germination of conidia of Paecilomyces fumosoroseus on the cuticle of the siverleaf whitefly, Bemisia argentifolii.
  64. (1982). Growth and accumulation of solutes by Phytopthora cinnamomi and other lower fungi in response to changes in external solute potential. doi
  65. Growth and formation of true conidia by Metarhizium flavoviride in a simple liquid medium. doi
  66. (1983). Growth and sporulation of Beauveria bassiana and Metarhizium anisopliae in a basal medium containing various carbohydrate sources. doi
  67. (1978). Growth and sporulation of Beauveria bassiana and Metarhizium anisopliae on media containing various amino acids. doi
  68. (1975). Growth and sporulation of Metarhizium anisopliae and Beauvcria bassiana on media containing various peptone sources. doi
  69. (2000). Hydrophobins, the fungal coat unravelled. doi
  70. (1996). Improved biocontrol of peach twig blight by physiological manipulation of Epicoccum nfgrum.
  71. (1994). Improved biological control by changing polyols/trehalose in conidia of entomopathogens. In:
  72. (2001). Improving water stress tolerance of the biocontrol yeast Candida sake grown in molasses-based media by physiological manipulation. doi
  73. (1997). Induction of submerged conidiation of the biocontrol agent Penicillium oxalicum. doi
  74. (1997). Infection of Schistocerca gregaria (Orthoptera: Acrididae) hoppers by Metarhizium flavoviride (Deuteromycotina: Hyphomycetes) conidia in an oil formulation applied under desert conditions. doi
  75. (1994). Infectivity of propagules of Paecilomyces fumosoroseus during in vitro development to Spodoptera frugipedra. doi
  76. (1989). Influence of accelerated germination of conidia on the pathogenicity of Metdrhizium anisopliae for Manduca sexta. doi
  77. (1994). Influence of culture age on rate of conidiospore germination in four deuteromycetous entomogenous fungi. doi
  78. (1999). Influence of culture conditions on production and freeze-drying tolerance of Paecilomyces fumosoroseus blastospores. doi
  79. (1991). Influence of nutrition during conidiation of Colletotrichum truncatum on conidial germination and efficacy in inciting disease in Sesbania exaltata. doi
  80. (1992). Influence of thermal ecology on the mycosis of a rangeland grasshopper. doi
  81. (1997). Inhibition of Beauveria bassiana proteases and fungal development by inducible protease inhibitors in the haemolymph of Galleria mellonella larvae. doi
  82. (1989). Inhibitory effects of cyclodepsipeptides, destruxins, from the fungus Metarhizium anisopliae on cellular immunity in insects. doi
  83. (1990). Initiation of germination of the entomopathogenic fungus, Metarhizium anisopliae. doi
  84. (1991). Integument as a barrier to microbial infections.
  85. (2000). Inter- and intra-specific variation in destruxin production by insect pathogenic Metarhizium spp., and its significance to pathogenesis. doi
  86. (1994). Interactions between fungal pathogens and insect hosts. doi
  87. (1994). Isoforms of the cuticledegrading Prl proteinase and production of a metalloproteinase by Metarhizium anisopliae. doi
  88. (1984). Levels of chitinolytic activity during development of three entomopathogenic fungi. Comparative Biochemistry and Physiology, doi
  89. (1998). Limits to the negative logarithmic relationship between moisture content and longevity in conidia of Metarhizium f avoviride. doi
  90. (1997). Liquid culture production of desiccation tolerant blastospores of the bioinsecticidal fungus Paecilomycesfumosoroseus. Mycological research, doi
  91. (1993). Long-term preservation of yeast cultures by liquiddrying. doi
  92. (1995). Long-term storage of Metarhizium flavoviride conidia in oil formulations for the control of locusts and grasshoppers. doi
  93. (1995). Manipulation of intracellular glycerol and erythritol enhances germination of conidia at low water availability. doi
  94. (1992). Mass production, formulation and field application of entomopathogenic fungi.
  95. (1997). Mechanisms of Deuteromycete fungal infections in grasshoppers and locusts: an overview. doi
  96. (2003). Media and fermentation processes for the rapid production of high concentrations of stable blastospores of the bioinsecticidal fungus Paecilomycesfumosoroseus. doi
  97. (1997). Membrane stabilisation in the dry state. Comparative Biochemistry and Physiology, doi
  98. (1996). Metarhizium spore surface antigens are correlated with pathogenicity. doi
  99. (1992). Micro-plate colourimetric assay for endo-acting cellulose, xylanase, chitinase, 1-3-, 6-glucanase and amylase extracted from forest soil horizons. doi
  100. (1984). Microbial growth at reduced water activities: some physicochemical properties of compatible solutes. doi
  101. (1992). Molecular cloning and regulatory analysis of the cuticle-degrading protease structural gene for the entomopathogenic fungus Metarhizium anisopliae. doi
  102. (1999). Mycopesticide production by fermentation: potential and challenges. doi
  103. (1988). Non-specific factors involved in the attachment of entomopathogenic deuteromycetes to host insect cuticle.
  104. (1976). Nucleic acids and fungal spore germination. In:
  105. (1994). Pathogenicity of the entomogenous fungi Metarhizium anisopliae and Beauveria bassiana against crucifer pests and the honey bee. doi
  106. (1988). Penicillin production by solid state fermentation. doi
  107. (2001). Physiological approaches to improving the ecological fitness of fungal biocontrol agents. In: doi
  108. (1982). Polyol accumulation by two filamentous fungi grown at different concentrations of NaCl. doi
  109. (1991). Polyol metabolism and osmotic adjustment in the mycelial ascomycete Neocosmospora vasinfecta doi
  110. (1970). Potassium transport in Neurospora. Evidence for a multisite carrier at high pH. doi
  111. (1984). Preservation of membranes in anhydrobiotic organisms: the role of trehalose. doi
  112. (1997). Product stability: from experimental preparation to commercial reality. In:
  113. (1987). Production and properties of Beauveria bassiana conidia cultivated in submerged culture. doi
  114. (1989). Production in vitro of appressoria by the entomopathogenic fungus Metarhizium anisopliae. doi
  115. (1992). Production of blastospores by three strains of Metarhizium anisopliae (Metch. ) sorokin in submerged culture. doi
  116. (1991). Production of conidial biomass of Trichoderma harzianum for biological control. doi
  117. (1999). Production of the fungal biocontrol agent Epicoccum nigrum by solid substrate fermentation: effect of water activity on accumulation of compatible solutes.
  118. (2001). Production of the fungal biocontrol agent Ulocladium atrum by submerged fermentation: accumulation of endogenous reserves and shelf-life studies. doi
  119. (1994). Production, formulation and application of the entomopathogenie fungus Beauveria bassiana for insect control: current status. doi
  120. (2001). Production, stabilisation and formulation of fungal biocontrol agents. In: doi
  121. (1988). Regulation of production of proteolytic enzymes by the entomopathogenic fungus Metarhizium anisopliae. doi
  122. (1989). Role of RNA and protein synthesis in stimulated germination of zoospores of the pathogenic fungus Phytopthora palmivora. doi
  123. (2001). Safety of fungal biocontrol agents. In: doi
  124. (1996). Safety of microorganisms intended for pest and disease control: a framework for scientific evaluation. doi
  125. (1991). Separation and characterization of grasshopper hemolymph phenoloxidases by sodium dodecyl sulfatepolyacrylamide gel electrophoresis. doi
  126. (1976). Some required events in conidial germination of Neurospora crassa. doi
  127. (1980). Spoilage of material of reduced water activity by xerophilic fungi.
  128. (1987). Stabilization of dry phospholipid bilayers and proteins by sugars.
  129. (1986). Stabilization of membranes in anhydrobiotic organisms. In: Membranes, Metabolism and Dry Organisms, doi
  130. (1984). Structure of insect culticle. In:
  131. (1996). Studies on the dynamics of the production of destruxins by Melarhizium anisopliae; direct highperformance liquid chromatographic and fast atom bombardment mass spectrometric analysis correlated with biological activity tests. doi
  132. (1963). Submerged cultivation of the fungus Metarhizium anisopliae (Metsch.
  133. (2000). Surface hydrophobicity, viability and efficacy in biological control of Penicillium oxalicum spores produced in aerial and submerged culture. doi
  134. (2000). Susceptibility of the legume flower thrips to Metarhizium anisopliae on different varieties of cowpea. doi
  135. (1992). The composition and attributes of Colletotrichum truncatum spores are altered by the nutritional environment.
  136. (2002). The destruxins: synthesis, biosynthesis, biotransformation, and biological activity. doi
  137. (1993). The enhanced infectivity of Metarhizium flavoviride in oil formulations to desert locusts at low humidities. doi
  138. (1995). The germination behaviour of Metarhizium anisopliae on the surface of aphid and flea beetle cuticles. doi
  139. (2003). The impact of nutrition on spore yields for various fungal entomopathogens in liquid culture.
  140. (1988). The mechanism of cryoprotection of proteins by solutes. doi
  141. (1995). The Physiology of Fungal Nutrition. Cambridge: doi
  142. (1993). The potential of mycoinsecticides.
  143. (1988). The role of destruxins in the pathogenicity of three strains of Metarhizium anisopliae for the tobacco hornworm Manduca sexta. doi
  144. (1988). The role of extracellular chymo-elastase in the virulence of Metarhizium anisopliae for Manduca sexta. doi
  145. (2000). Total lipids and fatty acids of strains of Metarhizium anisopliae. doi
  146. (2001). Toxic metbolites of fungal biological control agents. In: doi
  147. (1961). Toxic substances to insects, produced by Aspergillus ochraceus and Oospora destructor. doi
  148. (1985). Traits associated with virulence to the aphid Macrosiphoniella samborni in eighteen isolates of Verticillium lecanii. doi
  149. (2002). Trehalose-hydrolysing enzymes of Metarhizium anisopliae and their role in pathogenesis of the tobacco hornworm, Manduca sexta. doi
  150. (1977). Turgor pressure sensing in plant cell membranes. doi
  151. (2001). Use of Hyphomycetes fungi for managing insect pests. In: doi
  152. (1996). Variability of strains of Melarhizium anisopliae var. anisopliae (Metsch. ) sorokin in terms of protein content and spore germination.
  153. (1998). Variation in the electrophoretic karyotype of Brazilian strains of Metarhizium anisopliae. doi
  154. (1994). Viability and virulence of blastospores of Metarhizium anisopliae (Metch. ) Sorokin after storage in various liquids at different temperatures. doi
  155. (1997). Viability of stored conidia of Metarhi: ium flavoviride Gams and Rozsypal, produced under differing culture regimes and stored with clays. doi
  156. (1991). Volumetric properties of polyols (ethylene glycol, glycerol, mesoerythritol, xylitol and mannitol) in relation to their membrane permeability; group additivity and estimation of the maximum radius of their molecules. doi
  157. (1981). Water and microbial stress. In: doi
  158. (1999). Water and temperature relations of growth of the entomogenous fungi Beauveria bassiana, Metarhizium anisopliae, and Paecilomyces farinosus. doi
  159. (2003). Water availability affects the growth, accumulation of compatible solutes and the viability of the biocontrol agent Epicoccum nigrum.
  160. (1957). Water relations of food spoilage microorganisms. doi
  161. (1972). Water relations of sugar-tolerant yeasts: the role of intracellular polyols. doi

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