title: A novel carbon source-dependent genetic transformation system for the versatile cell factory Hypocrea jecorina (anamorph Trichoderma reesei).
abstract: Genetic transformation is an indispensable tool for basic fungal research, as well as a useful technique for directed improvement of industrial strains. Here we describe a simple and reproducible transformation system for the filamentous fungus Hypocrea jecorina. The system is based on hxk1 (encoding hexokinase) as selectable marker, a hexokinase-negative strain and D-mannitol, which is used as selective carbon source and osmotic stabilizer. Following transformation with the hxk1 gene, the obtained transformants were able to grow on D-mannitol as sole carbon source. Transformation efficiency achieved using D-mannitol as carbon source and osmotic stabilizer was roughly five times higher than that using D-sorbitol. The utility of this system was further demonstrated by transformation of H. jecorina with the egfp (encoding the enhanced green fluorescent protein) gene. Fluorescence microscopy revealed EGFP fluorescence in positive transformants. Our results demonstrated the feasibility of exploiting a carbon source metabolic pathway for the development of promising fungal transformation systems, which provides a new molecular toolbox for genetic modifications of the cell factory H. jecorina.
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, Jinan Shandong, China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Guangtao
authors.forename: Bernhard
authors.initials: B
authors.lastname: Seiboth
authors.forename: Cao
authors.initials: C
authors.lastname: Wen
authors.forename: Zhong
authors.initials: Z
authors.lastname: Yaohua
authors.forename: Li
authors.initials: L
authors.lastname: Xian
authors.forename: Tianhong
authors.initials: T
authors.lastname: Wang
mesh_terms: D002244:Carbon / Q000378:metabolism*; D018014:Gene Transfer Techniques; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006593:Hexokinase / Q000378:metabolism; D035901:Hypocrea / Q000235:genetics* / Q000378:metabolism*; D008353:Mannitol / Q000378:metabolism; D012641:Selection, Genetic; D014170:Transformation, Genetic
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D008353:Mannitol; D002244:Carbon; D006593:Hexokinase