Extracellular proteome of Aspergillus terreus grown on different carbon sources

Abstract

Extracellular proteins of filamentous fungi are important for biomedical and biotechnological applications. Aspergillus terreus not only comprises an important class of organisms that have significant commercial relevance to the biotechnology industry, but also is an emerging fungal pathogen. However, no information is available on the extracellular proteome of A. terreus. Thus, we analyzed the extracellular proteomes of A. terreus under different culture conditions using sucrose, glucose, or starch as a main carbon source. A total of 82 protein spots including 39 unique proteins was successfully identified by 2-DE and nano-LC-MS/MS. Of these, 12 proteins were detected in the presence of at least two different carbon sources, whereas 16 proteins were unique to sucrose-, 3 to glucose-, and 8 to starch-grown A. terreus. Most of the proteins with known functions are hydrolytic enzymes, such as hydrolases, glycosylases and proteases, some of which include potential allergens. Both oryzin and a predicted protein (ATEG_07481) were the most abundant in all three media. Particularly, oryzin was highly secreted in high concentration sucrose medium. These proteomic data will be useful for studying protein secretion in further detail, and finding fusion partners for the extracellular production of homologous or heterologous proteins in A. terreus.