Abstract: | A process has been developed that allows a direct conversion of lignocellulosic materials into fungal biomass. The thermotolerant white-rot fungus Sporotichum pulverulentium has been used in continuous laboratory fermentations as well as in a 25 m3 batch fermentation. Fungal cell mass for feeding trials was produced and the economics of the process were estimated. The investigation shows that the process works satisfactorily on the small continuous scale as well as in the large batch culture. The process also seems easy to scale up. The economic evaluations show the conversion of solid lignocellulosic materials to protein feed is not feasible by our process unless the material to be fermented has a certain negative value. A mixed wastewater, such as the white water system in paper and fiber board mills, containing both water soluble mono- and oligosaccharides and solid lignocellulosic material, can, however, be fermented in an economically feasible way due to the combined effect of protein production and water purification. Data on the nutritional value of the product are presented in an accompanying paper. |