Comparison of precipitation and flotation methods for the enrichment of Rhodotorula glutinis

In order to compare methods of enrichment of Rhodotorula glutinis from a fermentation broth,this paper examines the effect of fermentation broth components on flocculation using polyacrylamide. The optimal flocculant type and dosage were identified for the methods of precipitation and flotation,and a comparison of the economic cost of the separation methods was carried out. The results showed that the fermentation broth components had an influence on flocculation. The best flocculants for the two methods were a mixture of polymeric ferric sulfate(SPFS) and polyacrylamide. The optimal final concentrations in the compound flocculant for the precipitation method were 500 mg/ L and 40 mg/ L,respectively,giving a cell removal ratio of up to 95%. The optimal final concentrations in the compound flocculant for the flotation method were 500 mg/ L and 60 mg/ L,and the flotation ratio was 90%.