Abstract:
“Yellow water”, as a by-product of Bai jiu, contains abundant nutrients and has great utilization value. The “yellow water” was diluted in different proportions to make diluted “yellow water” medium (“yellow water” was the only nutrient source, without any exogenous nutrients added). In the “yellow water” medium with different dilution ratios, statically fermentation with
Gluconobacter was carried out to produce BC, and physicochemical indexes such as BC output and BC yield were determined in the fermentation broth during static culture fermentation at 30 ℃ for 14 d.The results showed that the optimal dilution ratio of “yellow water” was 2:8. Under this condition, the BC output reached the highest value (2.42 g/L), which was 53.2% higher than that of HS medium (1.58 g/L). The BC yield was 93.77%, increased by 813.05% compared with HS medium. Further the changes in BC production and physicochemical indexes of
Gluconobacter during the fermentation process were detected, the reducing sugar consumption rate and remaining reducing sugar content of the 2:8 dilution ratio yellow water medium after fermentation were 64.84% and 1.36 g/L, respectively, lower than the control group of the same period. Among the mediums with different sterilization methods, the BC output in the filter sterilization medium was 3.19 g/L, and the BC yield was 107.56%. Compared with the high-pressure humid heat sterilization, they also increased significantly. Therefore, using “yellow water” as the sole source of nutrients not only improves BC output and reduces BC production costs, but also provides a new way to utilize yellow water and product BC.