Optimization Production of Lactobacillus reuteri Exopolysaccharides and Its Bioactivity Analysis
| Autor: | Pin-Chieh Chen, 陳品潔 |
|---|---|
| Rok vydání: | 2017 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 105 Lactobacillus reuteri DSM17938 is a human-borne probiotic that has some beneficial to human health, such as improving infantile abdominal cramps, increasing Helicobacter pylori eradication, tooth care and improving gastrointestinal symptoms. In this study, we discuss the antioxidant and anti-inflammatory effects of extracellular polysaccharide produced by L. reuteri DSM17938. The results showed that L. reuteri DSM17938 fermentation broth was centrifuged after 18 hours of culture, and had the antioxidant effect of DPPH radical was 84.28 ± 0.37%, ferrous ion chelation rate was 97.78 ± 0.32%, reducring power was 236.53 ± 20.9 g/L, the trolox equivalent antioxidant capacity was 405.32 ± 8.17μM. The optimum experiment was carried out by using the response surface methodology (RSM) and choose three factors, which is galactose concentration (17 ± 5%), temperature (22.6 ± 5 ℃) and pH (6.8 ± 1). The results showed that the concentration of galactose 17.12%, culture temperature 22.9 ℃, pH 6.5, L. reuteri DSM17938 extracellular polysaccharide production reached the highest content of 643.32 ± 10.7 mg/L, the yield was higher than the original culture method 2.3 times. The original culture method: glucose concentration 2%, temperature 37 ℃, PH 6.4, the extracellular polysaccharide production yield 220.92 ± 0.94 mg/L. The antioxidant and anti-inflammatory effects of the extracellular polysaccharides in the fermentation broth were collected by alcohol precipitation. The DPPH free radical scavenging power, reducing power and trolox equivalent antioxidant capacity were observed that the antioxidant capacity of the supernatant was significantly larger than that of extracellular polysaccharide, But the chelating rate of extracellular polysaccharide was 97.47 ± 0.47%, which was significantly higher than original fermentation supernatant 70.11 ± 0.53%. Extracellular polysaccharide was inferred the Fe2 + - Ferrozine complexes, have the ability to capture and chelate metal ions. In the anti-inflammatory experiment, using LPS induced RAW264.7 macrophage inflammation, the amount of nitric oxide production was 33.36 ± 2.12 μM, adding extracellular polysaccharide 200 mg/L, the amount of nitric oxide production decreased significantly to 12.96 ± 1.07 μM. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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