Use of stillage grain from a rice-spirit distillery in the solid state fermentation of Ganoderma lucidum

The feasibility of reusing stillage grain as a substrate for the cultivation of Ganoderma lucidum in solid-state fermentation is evaluated. Cultures were carried out in test tubes or propylene bags and G. lucidum was cultivated on stillage grain supplemented with wheat bran, ground rice or sawdust at different ratios. The effect of mixed ratios on the production of mycelia and fruit body was investigated. The compositions of fruiting body were also analyzed and compared. The additions of NH4H2PO4 and CaCO3 favored mycelial growth in the test-tube cultures. Due to its high content of carbohydrate and nitrogen, stillage grain was considered as a nutritive substrate for mycelial growth. However, too much addition of stillage grain might result in the diminution of compost voidage and had an adverse effect on mycelial growth in propylene-bag cultures. The results obtained from propylene-bag cultures reveal that the substrate type altered not only the shape of fruiting bodies but also their constituents. Sawdust supplemented with stillage grain at a ratio 4:1 at a water content of 60% was optimal for the production of fruiting body. High ratios of stillage grain might lead to an increase of total dry weight of fruit body, but also caused the formation of antler branches and smaller fruiting body, which contained higher amounts of reducing sugars and lower amounts of polysaccharide than those of the control. (C) 2002 Elsevier Ltd. All rights reserved.