Nitrogen content of SHIITAKE mushroom [Lentinus edodes (Berk.) Sing.] cultivated on sawdust medium and dependence on that in the medium

Abstract

Shiitake mushroom [0Lentinus edodes (Berk.) Sing.] was cultivated on sawdust medium to which had been added okara,the insoluble residue of homogenized soybean (the waste product of tofu manufacture), rice bran and corn bran at concentrations of 5, 10, 15, 25 and 35%, respectively. Total nitrogen in the medium and fruit bodies cultivated on the sawdust medium was determined. Fruit bodies were analyzed for total amino acids, amide-N, free amino acids, nucleic acids and chitin. Nitrogen content of fruit bodies cultivated on sawdust medium was closely related to that in the medium. Nitrogen content of the sawdust medium was related to amino acid, nucleic acid and chitin contents. No significant relation between lentinic acid in fruit bodies and nitrogen content in the medium was observed. The amount of lentinic acid in fruit bodies cultivated on sawdust medium containing rice bran and corn bran was about 2 times that cultivated on okara-added medium. Nitrogen content of fruit bodies is thus shown to be affected by nitrogen sources present in the medium. High levels of nitrogen in sawdust medium should decrease carbohydrates in fruit bodies cultivated on the medium, thus making the fruit too soft for eating.