Project description:Metabolites from a collection of selected fungal isolates have been screened for insecticidal activity against the aphid Acyrthosiphon pisum. Crude organic extracts of culture filtrates from six fungal isolates (Paecilomyces lilacinus, Pochonia chlamydosporia, Penicillium griseofulvum, Beauveria bassiana, Metarhizium anisopliae and Talaromyces pinophilus) caused mortality of aphids within 72 h after treatment. In this work, bioassay-guided fractionation has been used to characterize the main bioactive metabolites accumulated in fungal extracts. Leucinostatins A, B and D represent the bioactive compounds produced by P. lilacinus. From P. griseofulvum and B. bassiana extracts, griseofulvin and beauvericin have been isolated, respectively; 3-O-Methylfunicone and a mixture of destruxins have been found in the active fractions of T. pinophilum and M. anisopliae, respectively. A novel azaphilone compound, we named chlamyphilone, with significant insecticidal activity, has been isolated from the culture filtrate of P. chlamydosporia. Its structure has been determined using extensive spectroscopic methods and chemical derivatization.
Project description:To determine secreted proteins that involved in adaptation of nutrient sources and response to nutrient stresses, we analyzed transcriptomes of Pochonia chlamydosporia strain 170 under three different nutrient conditions, CD (nutrient rich medium) that was predicted to repress parasitism, MM (nutrient-poor liquid minimal medium) that was predicted de-repress genes associated with parasitism, and MM-eggs(minimal medium with root-knot nematode eggs) that was prepared to induce parasitism.
Project description:The objective of this study was to purify, characterize, and phylogenetically and structurally analyze the dextranase produced by the fungus Pochonia chlamydosporia. Dextranase produced by the fungus P. chlamydosporia was purified to homogeneity in two steps, with a yield of 152%, purification factor of 6.84 and specific activity of 358.63 U/mg. Its molecular weight was estimated by SDS-PAGE at 64 kDa. The enzyme presented higher activity at 50 °C and pH 5.0, using 100 mM citrate-phosphate buffer, was inhibited by Ag1+, Hg2+, Cu2+, Mg2+, and presented KM of 23.60 µM. Mature dextranase is composed of 585 amino acids residues, with a predicted molecular weight of 64.38 kDa and pI 5.96. This dextranase showed a strong phylogenetic similarity when compared to Trichoderma harzianum dextranase. Its structure consists of two domains: the first composed by 15 ? strands, and the second composed by a right-handed parallel ?-helix.
