Abstract: A exogenous gene expression system was established in P. chrysogenum strain by using acetamidase(amds) gene as selection markers. The Cytoplasm-PEG transformation system was constructed including preparations and reuses of P. chrysogenum Cytoplasm and expression of exogenous gene. The two plasmids pVHbM and pVHbⅠ for expression of VHb in filamentous fungi were constructed. We were able to introduce VHb gene into P. chrysogenum by co-transformation of plasmid pVHbM or/and pVHbI with the Selection pUcamds markers. Some of transformants integrated the VHb gene. The expression level of VHb protein was related with the position and copies for integrating VHb gene into chromosome of filamentous fungi, different transformants had different efficiency. Valence of penicillin enhanced by a factor of 39% in shake-flask experiments for penicillium chrysogenun YH876 variants.

Key words: Vitreosicilla hemoglobin gene, Expression, Chrysogenum