Heterologous expression in Aspergillus nidulans of a Trichoderma longibrachiatum endoglucanase of enological relevance

An Aspergillus nidulans transformant expressing the Trichoderma longibrachi atum endoglucanase 1 gene (egl1) has been constructed. The extracellular pr oduction of EGL1 in different culture media has been studied, and a medium has been found in which EGL1 is the predominant extracellular protein produ ced. The enzymatic properties of the heterologously produced EGL1 are very similar to those of the native enzyme. Grape maceration in the presence of culture filtrate enriched in EGL1 resulted in increased release of aroma pr ecursors, particularly in the case of aromatic grapes. Cryoscanning electro n microscopy of the flesh of grapes treated with EGL1-enriched culture filt rate revealed degradation of the cell wall matrix.