Cuixia Chen,Shaopeng Ding,Dezheng Wang,Zhimin Li,Qin Ye
In this study, the production of succinic acid from cassava starch and raw cassava instead of glucose by Escherichia coli NZN111 was investigated. During the two-stage fermentation, simultaneous saccharification and fermentation (SSF) was applied in the anaerobic stage. The results showed that both the productivity and specific productivity in the process conducted at 40 °C were higher than those in the cultivation conducted at 37 °C. The yield of succinic acid based on the amount of added starch reached the highest level 0.86 g/g and cassava starch was almost totally hydrolyzed in the SSF process. With the improved cell density, 127.13 g/L of succinic acid was obtained. When the liquefied crude cassava powder was used directly in SSF, 106.17 g/L of succinic acid was formed. The result showed that crude cassava powder could be another cheap raw material for succinic acid formation.
Tao Xu,Weisu Huang,Jiajia Liang,Yongheng Zhong,Qi Chen,Fan Jie,Baiyi Lu
The different health effects between starch and whole flour from tubers are rarely studied. Here, we investigated the effects of cassava flour (CF), cassava starch (CS), potato flour (PF), and potato starch (PS) on gut health and gut microbiota of normal rats. Feed analysis showed that CF and PF diet provided significantly more slowly digestible and resistant starch, less rapidly digestible starch. Compared with rats fed with PS and CS diets, rats fed with PF and CF diets gained less body weight and have tighter intestinal barrier. Butyric acid contents were increased by tuber flours. CF and PF selectively promoted the relative abundance of Akkermansia and Eubacterium ruminantium in cecal and colonic content. In conclusion, tuber flour has intestinal protection, body weight control, and gut microbiota improving ability compared with starch. The different composition of starch might be the basis for these effects.