Fruit-processing wastes including apple pomace, cranberry pomace and strawberry pomace were used as substrates for polygalacturonase (PG) production by Lentinus edodes through solid-state fermentation. Strawberry pomace was the best substrate for highest pc yield, followed by apple pomace. while cranberry pomace was not a suitable substrate for PG production in this study. The highest PG activity was obtained after 40 days of culture and the yields from strawberry pomace, apple pomace and cranberry pomace were 29.4 U, 20.1 U and 14.0 U per gram of pomace, respectively. PG activity was increased by the addition of polygalacturonic acid in the apple pomace and cranberry pomace media, but was not affected in strawberry pomace medium. The PG produced by L. edodes from strawberry pomace exhibited a maximal activity at 50 degrees C and at pH 5. The enzyme was fairly stable up to 50 degrees C and between pH 3.0 and 6.5. The acid tolerant property of the enzyme made it suitable for applications in most fruit and vegetable processing industries. This value-added bioconversion strategy may be applicable for the utilization of other food processing wastes. (C) 2000 Elsevier Science Ltd. All rights reserved.