title: Label-Free Differential Proteomics and Quantification of Exoenzymes from Isolates of the Entomopathogenic Fungus Beauveria bassiana.
abstract: Beauveria bassianais an entomopathogenic fungus that grows both in vivo and in vitro. In vivo it can colonize live insect hosts, and tissue digestion occurs by secreted hydrolytic exoenzymes. It can also colonize dead insect tissue provided this is free from competing microorganisms. Depending on whether the host is alive or dead the expression (quality/quantity) of the exoenzymes may vary. We have grown several isolates ofB. bassianain shaking flasks for 120 h at 25 °C in order to evaluate the maximal exoenzyme production using two diet regimes. As sole carbon, nitrogen, and phosphate sources we used 1% shrimp chitin and either 0.5%w/vof dead intact American cockroach (Periplaneta americana) or their isolated cuticles. This is the first report of a differential proteomics ofB. bassianaexoenzymes performed by label-free nano-LC MS/MS. Total proteolytic enzyme activity was mainly due to Pr1A or Pr1B depending on the isolate and the diet regime. The most differentially secreted enzymes were: the cuticle-degrading subtilisin Pr1A, GH13 alpha-glycosidase, glucan endo-1,3-beta-glucosidase, subtilisin-like proteinase Spm1, lipase 1, beta-1,3 exoglucanase, and endo-1,3-beta-glucosidase. Among theB. bassianaisolates analyzed, Bb 678 and Bb BG were the most active in Pr1A secretion.
authors.affiliation: Department of Molecular Biology, Aarhus University, Flakkebjerg, Forsøgsvej 1, 4200 Slagelse, Denmark. giuseppe.dionisio@mbg.au.dk.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Dionisio
authors.affiliation: Department of Agroecology-Entomology and Plant Pathology, Aarhus University, Flakkebjerg, Forsøgsvej 1, 4200 Slagelse, Denmark. per.kryger@agro.au.dk.
authors.forename: Per
authors.initials: P
authors.lastname: Kryger
authors.affiliation: Department of Agroecology-Entomology and Plant Pathology, Aarhus University, Flakkebjerg, Forsøgsvej 1, 4200 Slagelse, Denmark. tove.steenberg@agro.au.dk.
authors.forename: Tove
authors.initials: T
authors.lastname: Steenberg
keywords: Beauveria bassiana; Progenesis QI for proteomics; chitinases; cockroach; cuticle-degrading serine proteinase; differential proteomics; exoenzymes; subtilisin protease