旧报纸等作为培养基栽培各种菌类城市最重要的研究课题之一是垃圾问题。以东京为例，去年一年的的垃圾量约５００万ｔ，现在还在不断地增加。例如，１９８５年到１９８７年三年间的增加量是京都市一年的垃圾量，超过６２．７万ｔ，其中以纸类最多，占东京都市整个垃圾量的... One of the most important research topics in the cultivation of various fungi cities, such as old newspapers, is the garbage problem. Take Tokyo as an example. Last year, the amount of rubbish was about 5 million tons, which is still increasing. For example, the increase in the three years from 1985 to 1987 was the amount of refuse collected in Kyoto for one year, exceeding 627,000 tons, of which the largest amount of paper accounted for the entire amount of refuse in Tokyo municipality.