Pseudomonas simiaeMHR6产胞外多糖条件优化及抗氧化活性

Optimization of culture conditions and antioxidantactivity of exopolysaccharides produced byPseudomonas simiae MHR6

摘要:

【目的】 研究培养条件对Pseudomonas simiae MHR6 生长及胞外多糖（EPS）产量的影响，并探究其抗氧化活性，为新型农业生物制剂的开发利用提供可靠的理论依据。【方法】 以EPS 产量为指标，通过单因素试验对菌株MHR6 产EPS 条件进行优化，并对EPS 的羟基自由基（OH-）、超氧阴离子（O2·-）和过氧化氢（H2O2）的清除作用进行了研究。【结果】 经优化后，MHR6 产EPS 的最佳培养条件是：培养时间5 d、温度28 ℃ 、初始pH 值8、接种量3%。当EPS 质量浓度为1. 0 mg/mL 时，其OH-、O2·-和H2O2 的清除率分别为56. 94%、64. 08% 和31. 69%。【结论】 最佳培养条件下EPS 产量达到最大值，为6. 16 mg/mL，比优化前提高了24. 9%。抗氧化实验结果表明MHR6 所产的EPS 具有良好的抗氧化活性。

Abstract:

【Objective】 In this paper，the effects of culture conditions on the growth of Pseudomonas simiaeMHR6 and the production of exopolysaccharides（EPS） were studied， and the antioxidant activity of P. simiaeMHR6 was investigated，providing a reliable theoretical basis for the development and utilization of new agriculturalbiological agents.【Method】 With the yield of EPS as the index，the EPS production conditions by MHR6 was optimizedby the single factor test. Subsequently，the antioxidant activity was determined by OH- ，O2·- and H2O2 scavengingrate of EPS.【Result】 The results showed that after optimization， the optimal culture conditions for MHR6 toproduce EPS were as follows：culture time 5 d，temperature 28 ℃ ，initial pH value 8，inoculation amount 3%. Whenthe mass concentration of EPS was 1. 0 mg/mL，the scavenging rates of OH-，O2·- and H2O2 were 56. 94%，64. 08%and 31. 69% respectively.【Conclusion】 Under the optimal culture conditions，EPS yield reached the maximum valueof 6. 16 mg/mL，which was 24. 9% higher than that before. Antioxidant activity results showed that EPS had strongantioxidant activity.