The use of a mixed culture of Geotrichum candidum,Candida krusei and Hansenula anomala for microbial protein production from whiskey distillery spent wash

Summary The use of a mixed culture of Geotrichum candidum, Hansenula anomala and Candida krusei for microbial protein production and treatment of whiskey distillery spent wash was investigated in both batch and continuous culture. Although capable of assimilating the same substrate constituents in pure culture the organisms used different constituents for growth in mixed continuous culture, allowing a stable mixed population to be established. The relative proportions of the three organisms in the population was dependent on the dilution rate.The mixed culture did not give superior yields or productivities, but did give proportionally greater COD reduction and would be expected to bemore stable and resistant to contamination.At a dilution rate of 0.10 h^–1 the mixed culture gave a biomass yield of 4.8 g l^–1, containing 55% crude protein, with a COD reduction of 31.5%, while in mixed batch culture a biomass yield of 12.5 g l^–1, containing 48% crude protein, was obtained with a COD reduction of 54.9%.