Use of biogas fluid-soaked water hyacinth for cultivating Pleurotus geesteranus

Experiments were carried out to test the viability of growing Pleurotus geesteranus on media containing varying amounts of crushed water hyacinth slices, which were soaked in pig farm biogas fluid and dried. The water hyacinth material was utilized to substitute sawdust in the media for mushroom cultivation. Mushroom fruiting bodies harvested were evaluated for yield, amino acid and heavy metal contents. Among the eight treatment groups, the greatest yield and highest amino acid content in the mushrooms were obtained when the proportions of water hyacinth and sawdust in the medium were equal. The concentrations of heavy metals, Hg, Pb and Cd, in most of the present mushroom samples did not exceed the maximum allowed levels according to the limits set forth by the food hygienic and safety regulations for edible mushrooms in China. The proposed waste utilization of water hyacinth could conceivably benefit the environment in various aspects including conservation of forest by reducing the demand on natural woods for mushroom production. (C) 2009 Elsevier Ltd. All rights reserved