Abstract: In order to reduce the serious environmental pollution from fiberboard production by wet process,utilization of fiberboard wastewater for production of fodder yeast was studied.The research results showed that two roll press in the alkaline pulp production or modified horizontal belt filter could be used as extraction equipment,and revealed that the optimum conversion conditions were:sulfuric acid concentration 0.2%,temperature 160℃,retention time 10 min,A screened strain Candida tropicalis AS 2.565 was used for yeast fermentation.The basic fermentation parameters were:sugar concentration 1.0%,temperature 28～33℃,pH 4.0～4.5.Fermentation results showed that yeast yield was 40%～50%,reached the general level of industry production,and the protein content of yeast was 50%, higher than the qualitative index of superior grade fodder yeast standard of Chinese Light Industry Ministry.The removals of BOD₅ and COD_cr detected were 80% and 70% respectively,approximating to the international level of the same research.

Key words: fiberboard, wastewater, fodder yeast