2.4. Solid state culture and submerged culture
In solid state culture, one unit of cutter square (5 mm × 5 mm, prepared by a self-designed cutter) of the activated P. eryngii mycelium was inoculated into MHP agar plate (containing 1.5% MHP and 2.0% agar, with pH adjusted to 5.80 using 1 N HCl) at 25 8C for 7 days. In submerged culture, 100 mL of seed culture medium was inoculated with one unit (5 mm ×5 mm) square of activated P. eryngii mycelium and cultivated at 25 8C, 100 rpm for 7 days; 10%(v/v) of the seed culture was inoculated into the main medium containing 2.0% glucose, 0.1% yeast extract, 0.5% peptone, 0.1% KH2PO4, and 0.1% MgSO4 7H2O,with pH adjusted to 5.80 using 1 N HCl, where glucose was separately autoclaved. The cultivations were carried out in a rotary shaker set to 100 rpm, at 25 8C for 7 days. In the case of the study of carbon and nitrogen sources in submerged culture, various carbon (2%, w/v) and nitrogen sources (0.6%, w/v) were replaced respectively in the main medium.