Abstract: Glutamine synthetase (GS) is a central enzyme of nitrogen metabolism in fungi. A single nitrogen of minimal medium was designed to investigate the type and concentration of nitrogen source and the regulation of GS activity in culture the mycelia of Pleurotus eryngii. The transcription of PE-GS was measured by Real Time RT-PCR and the data of enzymatic activity of GS and the biomass of Pleurotus eryngii were analyzed. Fluorescence quantitative PCR showed that both urea and NH+4 could inhibit GS gene expression level and GS enzyme activity. NO-3 could improve GS gene expression level and GS enzyme activity, but the ability to produce mycelium biomass with NO-3 nitrogen source was poor in Pleurotus eryngii.

Key words: Pleurotus eryngii, glutamine synthetase, nitrogen source