Jun-ichi Yaguchi*, Kaoru Chigusa*, Yoshihisa Minegishi**, and Toshihisa Tamura**

*Nishihara Environmental Sanitation Research Co.Ltd., Division of Bio-research
**Japan Microbe Chemical Co.Ltd.

+ Correspondence should be addressed to Jun-ichi Yaguchi:
Nishihara Environmental Sanitation Research Co.Ltd., Division of Bio-research
(3-6-18, Shibaura, Minato-ku, Tokyo, 108, Japan)

Abstract

Proliferated yeasts were recovered from the wastewater treatment process of the food industry and yeast cell contents were extracted with various procedures. Of these extraction methods, autolysis and heat treatment under acid or alkaline condition were evaluated to be rather effective. Alkaline hydrolysis ranging from 100 to 120*C[Celsius degeree] at pH over 12 resulted in more than 80% of the extraction yield. The three yeast extracts prepared were applied to the medium component for microorganism growth and mushroom cultivation. Since they equally supported the growth of lactic acid bacteria which invariably had complex nutritional requirements in comparison to the commercial ones, three yeast extracts were confirmed to stand comparison with them. Furthermore, the promoting effects of the yeasts and the yeast extract through autolysis on mycerial growth and fruiting of mushrooms was also proved.

Key words: yeasts, autolysis, yeast extract, lactic acid bacteria, mushroom