Lentinula edodes (Shiitake mushroom) secretes various enzymes, including laccase (Lcc), which is a lignin degrading enzymes with environmental bioremediation advantages. In this study, we investigated enzyme activity in the waste water ("Jomen-sui") from L. edodes sawdust Jomen-culture, removal of endocrine disrupting chemicals (EDCs) by Jomen-sui, changes of Lcc activity in Jomen-sui, and the concentration methods of Jomen-sui. Lcc, cellulase, xylanase, and acid proteinase activities were detected in Jomen-sui of L. edodes sawdust Jomen-culture at 22 days after induction of fruiting. After incubation of 500ng/ml bisphenol A and 4-t-octylphenol with this Jomen-sui, the EDCs were decreased to 17.9% and 23.5%, respectively. Lcc activity in the Jomen-sui was increased until about 3 to 4 weeks after fruiting induction, and then decreased immediately. Jomen-sui could be concentrated about 100- to 200-fold by ultrafiltration method, and then powdered by a freeze-drier without inactivation of Lcc. Lcc activity in the concentrated Jomen-sui was maintained for 100 days at 4℃. Thus, Jomen-sui is applicable for bioremediation as it can remove EDCs, be concentrated, and be preserved for a long time without Lcc inactivation.

View full abstract

To establish an improved method for producing Shiitake mushrooms with high yield and quality in the sawdust-based cultivation, the temperature and moisture conditions for controlling the amount and position of primordium formation and fruit body flushing were examined. The number of primordia formed and fruit bodies flushed was successfully decreased by incubating a high-temperature treatment (27℃) for 7 days; however, control of the flushing position was difficult. Combined treatment of high temperature and water filling controlled the number of primordia and fruit bodies on the upper position. Thus, our novel method fruit body flushing from the upper position (FFUP) of a mycelial block, appears to be more beneficial than conventional methods.

View full abstract

The effect of dried soba-shochu distiller waste as a nutritional additive for supplementation in sawdust media on yield and nutritional quality of shiitake was investigated. The number and yield of shiitake increased about 20% and 17%, respectively, when shochu distiller waste was used concomitantly with rice bran. An increased yield of about 12% was also detected under commercial scale shiitake production. Shiitake harvested in sawdust media supplemented with shochu distiller waste contained high levels of amino acids, especially glutamic acid accounting for the umami taste, and glycine and alanine accounting for the sweet taste. These results show that dried soba-shochu distiller waste can be efficiently used as a nutritional additive for shiitake cultivation.

View full abstract

Micro-algae of Chlorella species are useful as a functional food. During the manufacturing process, a large quantity of nutrient-rich industrial waste, Chlorella extract residue (CER), is discharged. Here, the use of CER was investigated as a nutrient source in the production of edible mushrooms. Four edible mushrooms were cultivated in media containing CER; the culture media consisted of 5:1 to 5:3 ratios of Japanese cedar sawdust: CER. The 5:1 CER media resulted in superior mycelial growth compared to the other media. Furthermore, the 5:1 CER media showed trends towards increased fruiting body yield and reduced cultivation duration compared to the control media. Compared to the control media, the appearance of the mushrooms was almost identical, and the composition of the general components and minerals in the fruiting bodies were similar. However, the 5:1 media produced fruiting bodies with significantly higher vitamin and amino acid composition than that of the control media. Thus, the use of CER in mushroom culture may contribute to the utilization of industrial food waste, as well as serve to enhance the nutritional value of their fruiting bodies.

View full abstract