title: Measuring Chitinase and Protease Activity in Cultures of Fungal Entomopathogens.
abstract: Entomopathogenic fungi produce a variety of destructive enzymes and metabolites to overcome the unique defense mechanisms of insects. In a first step, fungal chitinases and proteinases need to break down the insect's cuticle. Both enzyme classes support the infection process by weakening the chitin barrier and by producing nutritional cleavage products for the fungus. In a second step, the pathogen can now mechanically penetrate the weakened cuticle and reach the insect's hemolymph where it starts proliferating. The critical enzymes chitinase and proteinase are also excreted into the supernatants of fungal cultures and can be used as indicators of virulence. Chromogenic assays adapted for 96-well microtiter plates that measure these enzymes provide a sensitive, fast, and easy screening method for evaluating the potential biocontrol activity of fungal isolates and may be considered as an alternative to laborious and time-consuming bioassays. Furthermore, monitoring fungal enzyme production in dependence of time, nutrient sources, or other factors can facilitate in establishing optimal growth and harvesting conditions for selected isolates with the aim of achieving maximum biocontrol activity.
authors: Bio-Protection Research Centre, Lincoln University, PO Box 85084, Lincoln, 7647, New Zealand. farmingmicrobes@gmail.com.|Biotelliga Limited, 4 Austen Place, Pukekohe, 2120, New Zealand. farmingmicrobes@gmail.com.
authors: Peter
authors: P
authors: Cheong
authors: Bio-Protection Research Centre, Lincoln University, PO Box 85084, Lincoln, 7647, New Zealand.
authors: Travis R
authors: TR
authors: Glare
authors: Bio-Protection Research Centre, Lincoln University, PO Box 85084, Lincoln, 7647, New Zealand.
authors: Michael
authors: M
authors: Rostás
authors: AgResearch, Lincoln Research Centre, Private Bag 4749, Christchurch, 8140, New Zealand.
authors: Stephen R
authors: SR
authors: Haines
mesh_terms: D000818:Animals; D002688:Chitinases / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D004789:Enzyme Activation; D057075:Enzyme Assays; D005658:Fungi / Q000201:enzymology*; D007313:Insecta / Q000382:microbiology
chemical_list: D002688:Chitinases; D010450:Endopeptidases
keywords: 96-Well plates; Chitinase; Chromogenic assay; Easy; Fast; Insect defense; Proteases; Sensitive