Attempt of the Cryopreservation of Shiitake (Lentinula edodes) Mycelia at a Temperature Zone around -18°C using a Domestic Freezer

Abstract

The preservation of four shiitake (Lentinula edodes) mushroom strains using mycelium-agar disks with several kinds of cryoprotectants (i.e. 10-40% (w/w) glucose aqueous solutions,10-40% (w/w) sucrose ones, 1-4% (w/w) sodium chloride ones and pure water) at a temperature zone around -18°C of a domestic freezer was investigated. The survival rate of the four strains (ANCT -05072, -05152, -09005, -12001) was 100% only in 40% (w/w) glucose aqueous solutions for 35 days. In 40% (w/w) sucrose ones, the rate of the three strains except ANCT-05072 was 100% for 100 days or more than 100 days. The rate of ANCT-09005 in the sucrose one was 100% until 180 days. Unlike saccharide aqueous solutions, a negative correlation in the survival rate and in the concentration of sodium chloride was observed. Except 1-2% (w/w) of sodium chloride aqueous solutions of ANCT-09005, the survival rate 100% maintenance periods of all others were 7 days or less than 7 days. Similarly, the rate 100% maintenance periods of the all strains using pure water were 7 days or less than 7 days. The survival rate in the cryopreservation using a domestic freezer is affected by a strain, but the concentrated saccharide sugar solutions were suitable for cryoprotectants of shiitake strains.