Production of Coconut Aroma in Solid-State Cultivation: Screening and Identification of Trichoderma Strains for 6-Pentyl-Alpha-Pyrone and Conidia Production

Abstract

The polyketide, 6-pentyl-alpha-pyrone (6-PP), has a characteristic coconut aroma and is produced by many Trichoderma species. In this study, we screened formerly isolated Trichoderma strains for 6-PP production grown using solid-state fermentation (SSF). Sugarcane bagasse supplemented with a nutrient solution was used as the support material for the culture. We detected outstandingly strong 6-PP production in the case of two Trichoderma strains in this experiment. The strains were identified based on internal transcribed spacer (ITS) sequence analysis as Trichoderma asperellum (G7 and G18). We also investigated the production of 6-PP in the case of the best Trichoderma strain selected (T. asperellum G7) from two types of cultivation (SSF and liquid cultivation (LC)). The same liquid medium was used to impregnate sugarcane bagasse. Results led to a 6-PP production 80 times higher (85.11 μg·g·DM−1) in SSF than that found in LC (10.00 μg·L−1) after eight days of cultivation. For this, the SSF is the best option to produce 6-PP compared to liquid cultures.