Proteolytic Activity of Edible Spruce Morchella esculenta

This study focused on the determination of non-specific proteolytic activity of edible spruce Morchella esculenta in water extract, phosphate-buffered saline (PBS) solution (pH = 7.5) extract and a suspension prepared from 200 mg DW (dry weight) of edible spruce in PBS solution (pH 7.5). A clear casein solution was used as a substrate. The absorbances were measured in quartz cuvettes at the wavelength of 280 nm against a blank with zero concentration of trypsin. Non-specific proteolytic activity was expressed as trypsin equivalents per kilogram of mushroom dry weight (mg.kg⁻¹ DW). All of the extracts demonstrated non-specific enzymatic activity. The highest activity was observed in the PBS suspension and the lowest enzymatic activity was measured in the water extract of the Morchella esculenta fungi. The non-specific proteolytic activity decreased in the following order: PBS suspension extract (pH 7.5; 22.9 mg.kg⁻¹ DW), followed by PBS extract (pH 7.5; 13.6 mg.kg⁻¹ DW) and finally the water extract (10.94 mg.kg⁻¹ DW).