Screening of Yeast Suitable for Seriflux Treatment in Chinese Rice Wine

Abstract:

Seriflux is the by-product of the Chinese rice wine production，which has rich in nutrient with low pH. Direct wastewater treatment process of seriflux caused great economic burden because of the high COD and failed to utilize nutrient. For recycling the seriflux，108 yeast strains were isolated from the enviroment. According to the biomass and pigment production of the red yeast cultured in pH 3.5 medium，5 red yeasts with better characteristics were selected. Further study on cell population，pigment content and COD degradation rate of the yeast inoculated in seriflux，strain R-70 was screened as the suitable yeast. According to the morphological and physiological characteristics，combined with 26S rDNA sequence analysis result，R-70 was identified as Sporidiobolus pararoseus. Fermentation experiments of R-70 in seriflux showed that pH and the amount of ammonia nitrogen increased with during the culture process. The number of yeasts cells reached the maximum 7.8×107/mL at 36 h，and the pigment content reached a higher value 5.26 mg/L at 44 h. Meanwhile the COD decreased to the minimum at 44 h，the removal rate of COD was up to 91.12%. Sporidiobolus pararoseus R-70 is suitable for seriflux recycling with good performance.