Hypocrea atroviridis (Trichoderma atroviride) is used as organic plant protectant as it attacks and destroys pathogenic fungi. In this work its extracellular proteome was analysed while glucose or cell walls of Rhizoctonia solani, Botrytis cinerea and Pythium ultimum were used as carbon sources. The proteins secreted during the different growth conditions were separated through 2D gel electrophoresis. The main difference between the proteomes was the fact that H. atroviridis secreted far less proteins when grown on glucose than during the use of more complex carbon sources. Also the major component of the cell walls - chitin or cellulose - influenced the composition of the proteomes.
Selected spots from the different gels were subjected to tryptic digest and the resulting peptides were analysed through mass spectrometry, using a MALDI-TOF instrument. With the aid of MS/MS it was tried to identify the extracellular proteins.
The fragment ion spectra were used as well for database search as for manual interpretation. The applied databases included the public facilities MSDB, NCBInr and SWISS-PROT as well as expressed sequence tag (EST) databases of closely related organisms.
The protein which constituted the major component of the extracellular proteome secreted during growth on glucose was identified as plant defence response elicitor. It was called epl1 and further investigation showed its presence under all different growth conditions. Additionally various lytic enzymes which were secreted during growth on the different cell walls were identified.