Research on the decolorization of melanoidin by microorganisms. Part IV. Continuous decolorization of molasses waste water with mycelia of Coriolus versicolor Ps4a.

Abstract

Continuous decolorization of molasses waste water by mycelia of Coriolus versicolor Ps4a was studied using waste water from a baker's yeast factory, treated by means of methane fermentation and with activated sludge. Optimum decolorization with bare pellet-type mycelia in shaking flasks needed the addition of glucose (0.5%) and peptone (0.05%) and aerobic conditions (1ppm of dissolved oxygen). Continuous decolorization in a bubbling column reactor showed a decolorization yield of approximately 75% in only 20 hr at a dilution rate (D) of 0.03hr-1 under the optimum conditions. In order to continue the decolorization for a longer time, mycelia immobilized within Ca-alginate gel were tested in a bubbling column reactor under the optimum conditions. The immobilized mycelia showed an almost constant decolorization yield (65.7%) during continuous decolorization for 16 days at D=0.22hr-1.