Optimization of 6-pentyl-alpha-pyrone, lytic enzymes, and spores production byTrichoderma harzianum in solid state culture

International audienceCommonly the pests causing problems on food crops are treated with chemical pesticides, but the wrong and excessive application are causing severe damages to human health, to ecology by non-target organisms eliminated and the creation of pests resistant to pesticide. In recent years biopesticides have placed as a viable alternative to control pests and as a possible substitute for the traditional chemical used. Trichoderma is a filamentous fungus considered a biocontrol agent. It has been a very important model for study because of its mechanisms of action; nutrients and space competence, antibiotics production and lytic enzymes production. The production systems using solid substrates have shown excellent yields for the production of filamentous fungal spores. Solid state culture (SSC) allows the valorization of agroindustrial wastes having an impact on the worldwide ecology. This production system has the potential to produce value-added products such as antibiotics, pigments, aromas like 6-pentyl-alpha-pyrones (6-PP) and enzymes like cellulases, chitinases, amylases, etc.. In this investigation, a 6-PP, lytic enzymes and spores producing strain of two Trichoderma sp., were subjected to optimization of media and cultivation parameters for metabolites production.. Corresponding authors : Magalie BRUNO Phone/Fax: (33) 04 91 28 81 86 SSC was conducted in 250ml flasks containing 10g of mixed substrates were sterilized at 121 °C for 30 min. After cooling the medium was inoculated with a concentrated spore suspension of 2x107 spores/g dry matter (DM). Initial pH and moisture contents were 5.6 and 55 %, respectively. Cultures were carried out at 30 °C Results and interpretation of Hadamard design Results and interpretation of Hadamard design The Hadamard design showed that for T,harzianum G7 and T,harzianum G18 the optimized culture medium are different. As a result a medium of the following formula was predicted to be near the optimum, for producing metabolites in the culture filtrate of Trichoderma harzianum G7: Vine shoots, potatoes flour, jatropha, olive pomace, and olive oil (recuperation of 1mg/g substrate of 6-PP)