Zhang Le, Zhao Bo, Liu Chen-Jian, Yang En
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 Yunnan China.
Indian J Microbiol. 2020 Sep;60(3):334-345. doi: 10.1007/s12088-020-00865-8. Epub 2020 Apr 2.
SP8, isolated from traditional Chinese pickle juice, was utilized for the production of exopolysaccharides (EPSs), but the EPS yield was low under normal MRS medium. The single factor experiment and response surface methodology were used to optimize the medium components and culture conditions and the optimal conditions for EPS production were successfully obtained. Results showed that the optimum condition was glucose 22 g/L, yeast extract 30 g/L, fermentation temperature 35.6 °C, fermentation time 22 h and the theoretical EPS yield was 282.494 mg/L. The results were similar to the actual yield, 280.105 mg/L. By optimizing the culture conditions, the yield of SP8 EPS was improved by nearly 19 times. In the gas chromatography analysis, it was found that SP8 EPS consisted of d-rhamnose, arabinose, galactose, and d-acetylglucosamine, but glucose was not included, which was quite different from the reported heteropolysaccharide component of . Furthermore, the antioxidant activity of SP8 EPS was evaluated with the in vitro scavenging abilities on DPPH·, and ·OH. The in vitro antioxidant activity study indicated that SP8 EPS possessed certain antioxidant activity. All results demonstrated the potential of SP8 in the food and dairy industry.
从中国传统泡菜汁中分离出的SP8用于生产胞外多糖（EPSs），但在普通MRS培养基下EPS产量较低。采用单因素实验和响应面法对培养基成分和培养条件进行优化，成功获得了EPS生产的最佳条件。结果表明，最佳条件为葡萄糖22 g/L、酵母提取物30 g/L、发酵温度35.6℃、发酵时间22 h，理论EPS产量为282.494 mg/L。结果与实际产量280.105 mg/L相近。通过优化培养条件，SP8 EPS的产量提高了近19倍。在气相色谱分析中，发现SP8 EPS由d-鼠李糖、阿拉伯糖、半乳糖和d-乙酰氨基葡萄糖组成，但不包括葡萄糖，这与报道的杂多糖成分有很大不同。此外，通过对DPPH·、 和·OH的体外清除能力评估了SP8 EPS的抗氧化活性。体外抗氧化活性研究表明，SP8 EPS具有一定的抗氧化活性。所有结果证明了SP8在食品和乳制品行业的潜力。
