Liu Wei,Na Haining,Hu Changhui,Zhou Fang,Zhang Zhenyu,Guo Zhuo,Li Mian,Zhu Jin
With the aim to exhibit the advantages of catalytic accelerator in enhancing the selective hydrolysis of cellulose to sugar, cellulose is hydrolyzed in low acid aqueous system with catalytic accelerator. And then sugar products are extracted and fermented by yeast. By the assistance of catalytic accelerator, cellulose conversion rate and total reducing sugar yield are 95.7% and 90.9%. And the glucose yield is as high as 73.6%. The sugar products with high glucose content can be easily extracted from cellulose hydrolysate. Low toxicity of the sugar products to yeast is found during yeast fermentation. The glucose in cellulose hydrolysate can be fully consumed after 12 h. A highly actual ethanol yield is exhibited, which is equal to the actual yield level of standard glucose solution. The important role of catalytic accelerator in aqueous hydrolytic system to produce fermentable sugar is clearly reflected. Furthermore, a simple but effective way is established to efficient utilization of cellulose as an applicable carbon source for the conversion of more value-added chemicals and materials.
This study applied an in vitro fermentation model, whereby the catabolism of Porphyra haitanensis polysaccharides (PHP) was monitored coupled with the variations of microbiota composition and the concentration of short-chain fatty acids (SCFAs), so as to assess the effects of PHP on human intestinal microbiota. After 24 h anaerobic incubation, the level of microflora diversity increased significantly, as the microbiome structure was reshaped through promotion of intestinal probiotics proliferation and inhibition of pathogens growth. Besides, the final concentration of total SCFAs increased to 32.32 ± 1.81 mmol/L, and contained high amounts of acetic, propionic and butyric acid. Furthermore, the molecular weight of PHP decreased from 2.623 × 10 5 g/mol to 2.308 × 10 4 g/mol. The degree of polymerization of oligosaccharide products ranged from 2 to 9, with the main linkage patterns being 1 → 3 and 1 → 4 linked Gal p . The current study provides new insight on the probiotic activity of PHP within the human gastrointestinal tract.
危险品化学品经营许可证（带存储）