ABSTRACTImmersion of solid substrate fully colonized by the mycelium ofLentinula edodesin chilled water at 5 C for 24 h and treatment of mycelium grown in synthetic medium at 5 C for 24 h resulted in significantly earlier initiation and increase in dry weight of sporophores. Following the cold shock treatment, there was an increase in the degree of unsaturation of the polar lipids of the mycelium caused by the variation in the proportion of C18:2and C16:0. There was also an increase in the polar to nonpolar lipid ratio. Levels of phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and diphosphatidylglycerol in the mycelium were significantly (P<0.05) altered. A significant (P<0.05) increase in the uptake of glucose and aspartic acid was also observed as a result of the treatment.